lagunas mediterraneas temporales

1

MediterraneanTemporary PoolsVolume 1 – Issues relating to conservation, functioning and management

Grillas P., P. Gauthier, N. Yavercovski & C. Perennou

Production: Station biologique de la Tour du ValatDesign: Tapages PublicsIllustrations: Sonia Viterbi

Translated from French by Janet Clayton and John Phillips Cover: photos Jean Roché (above) and Dominique Rombaut (right)

© 2004 Station biologique de la Tour du ValatLe Sambuc - 13200 Arles - France

Readers are invited to reproduce texts and illustrations featured in this publicationprovided credit is given to the authors and to the Station Biologique de la Tour du Valat.

All photos rights reserved. No photographic part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying

except as may be expressly permitted in writing from the publisher.ISBN : 2-9103-6850-5

The LIFE “Temporary Pools”project

The LIFE “Temporary Pools” project took place during the period1999-2004. Its main objectives were to achieve the integratedmanagement of seven sites in Mediterranean France and todevelop management tools and methods for these fragile habitatswhich could be transferred to the Mediterranean scale.

The project was organised into seven site sections (cf. map) andtwo overarching theme-based sections “Awareness raising” and“Integrated management”). The Tour du Valat was in charge ofthe “Integrated management” section as well as the generalcoordination of the project. The other sections were delegated tosix local operators. The cost of the project was around 1,000,000 €,of which 50% was financed by the EU and the rest by 12 or sopartners.

PartnersEuropean Commission, Ministère de l’Ecologie et du Développe-ment Durable (MEDD) and its Directions régionales de l'environne-ment (PACA, Languedoc-Roussillon and Corsica), Languedoc-Roussillon region (Agence Méditerranéenne de l’Environnement),Corsica region (Office de l’Environnement de Corse), Provence-Alpes-Côte d’Azur region (Agence Régionale pour l’Environnement:ARPE), Agence de L’Eau Rhône-Méditerranée-Corse, Conservatoirede l’Espace Littoral et des Rivages Lacustres, Conservatoire Bota-nique National de Porquerolles, Conservatoire des Espaces NaturelsLanguedoc-Roussillon, Conservatoire Etude des Ecosystèmes deProvence Alpes du Sud (CEEP), Association de Défense de la Naturedes Pays d’Agde (ADENA), Association de Gestion de la RéserveNaturelle de Roque-Haute, Ecosphère, Institut Méditerranéend'Ecologie et de Paléoécologie (Université d'Aix-Marseille III),Ecole Pratique des Hautes Etudes (EPHE), Départements du Gardet de l’Hérault, Office National des Forêts (Gard and Var).

AchievementsThe project’s activities covered six major areas:

The furthering of knowledge and the drawing-up of managementplans Inventories of the fauna, flora and human activities were madeat most of the sites as well as more detailed studies of the speciesor locally important themes: perception of the pools by users andlocal players, a detailed inventory of the cupular micro-pools,monitoring of threatened species, etc. The results of these studiesserved as the basis for measures proposed in the managementplans drawn up for three of the sites.Finally, an initial inventory of the temporary pools in Medi-terranean France was carried out, enabling over 100 sites sup-porting almost 1000 pools to be identified.

Control over land ownership and land useControl over land use by organisations for the protection of naturalhabitats is an essential prerequisite for any management of tem-porary pools. In total, over 83 hectares were acquired within theframework of the project. In addition, management agreementswere made with owners (private or communal) on at least twosites, significantly increasing the area for which usage can be con-trolled in the mid term.

Management workExperimental management work took place on most of the sites:Scrub clearing, cleaning out, digging-out of a pool, pulling upinvasive exotic species, restoration of a filled-in pool, etc. Mostof this work was accompanied by careful monitoring of its impact,in order to draw lessons that could be transposed elsewhere.

Raising awarenessThe various site teams regularly interacted with and providedregular information to local inhabitants, elected political repre-sentatives and users. Numerous awareness-raising, communica-tion and environmental education initiatives took place:European “Green Days”, events for schools, leaflets, informationpanels, web pages, posters, educational module, press articles, TVprogramme, video cassette, etc. Local events were organised toencourage local inhabitants to protect the temporary pools.On the global scale, a resolution calling for the conservation oftemporary pools was drawn up by the project and adopted at theeighth Ramsar Conference in November 2002.

Integrated managementThis section provided the framework for discussion prior to allthe management work undertaken. It also allowed permanentexchanges to take place between the managers of sites and thescientists involved in the project: exchange visits between sites,theme-based workshops, coordination of the network, etc.Finally, this management handbook was published. A final inter-national conference was also organised, bringing together almost100 participants from all over Europe and the Mediterranean region.

CoordinationPermanent coordination between all these various activities andpartners was organised throughout the project. A steering com-mittee was set up and meetings organised, regular contacts weremaintained with the European Commission and all the partnersin the project.

Map of LIFE Programme Temporary Pool sites

CorsicaC1: Padulu

Languedoc-RoussillonL1: Etang de ValliguièresL2: Notre-Dame de l’AgenouilladeL3: Roque-Haute

Provence-Alpes-Côte d’AzurP1: Besse et FlassansP2: Colle du RouetP3: Plaine des Maures

Mediterranean Sea

Provence-Alpes-Côte d’Azur

Languedoc-Roussillon

Corsica

The operators and partners of the LIFE-Nature projet “Conservation of Mediterranean Temporary Pools” n° 99/72049

The operators

ADENA: Association de Défense de la Nature des Pays d’AgdeDomaine du grand Clavelet, F-34300 Agde, FranceTél.: +33 (0)4 67 01 60 23, fax: +33 (0)4 67 01 60 [email protected]

AGRN.RH: Association de Gestion de la Réserve Naturelle de Roque-Haute1, rue de la Tour, F-34420 Portiragnes, FranceTél. / fax: +33 (0)4 67 90 81 [email protected]

CEEP: Conservatoire Etudes des Ecosystèmes de Provence Alpes du Sud890, chemin de Bouenhoure Haut, F-13090 Aix-en-ProvenceTél.: +33 (0)4 90 47 02 01, fax: +33 (0)4 90 47 05 [email protected]

2. CEEP Var 1, place de la Convention, F-83340 Le LucTél: +33 (0)4 94 50 38 39, fax: 04 94 73 36 86

CEN-LR: Conservatoire des Espaces Naturels du Languedoc-Roussillon20, rue de la République, Espace République, F-34000 MontpellierTél.: +33 (0)4 67 22 68 28, fax: +33 (0)4 67 22 68 [email protected]

OEC: Office de l'Environnement de la CorseAvenue Jean Nicoli, F-20250 CorteTél.: +33 (0)4 95 45 04 00, fax: +33 (0)4 95 45 04 01

TDV: Station Biologique de la Tour du ValatLe Sambuc, F-13200 ArlesTél.: +33 (0)4 90 97 20 13, fax: +33 (0)4 90 97 20 [email protected], web site: www.tourdu valat.org

The partners

AME: Agence Méditerranéenne de l’EnvironnementEspace littoral de l’Hôtel de Région, 417, rue Samuel Morse, F-34000 MontpellierTél.: +33 (0)4 67 22 94 05, fax: +33 (0)4 67 22 94 [email protected]

ARPE: Agence Régionale Pour l'Environnement PACAParc de la Duranne, avenue Léon Foucault, immeuble Le LevantBP 432000, F-13591 Aix-en-Provence Cedex 03Tél.: +33 (0)4 42 90 90 90, fax: +33 (0)4 42 90 90 91

Agence de l’Eau RMC: Agence de l’Eau Rhône-Méditerranéee et CorseDirection de la Planification et de la Programmation, Unité Planification,2-4, allée de Lodz, F-69363 Lyon Cedex 07Tél.: +33 (0)4 72 71 26 00, fax: +33 (0)4 72 71 26 03

CBNMP: Conservatoire botanique national méditerranéeen de Porquerolles Castel Sainte-Claire, F-83418 Hyères cedexTél: +33 (0)4 94 12 82 30, fax: +33 (0)4 94 12 82 [email protected]

2. Antenne du Languedoc-RoussillonInstitut de Botanique, rue Auguste Broussonet, F-34090 MontpellierTél.: +33 (0)4 99 23 22 11, fax: +33 (0)4 99 23 22 [email protected]

CELRL: Conservatoire de l’Espace Littoral et des Rivages Lacustres1. Délégation Languedoc-Roussillon165, rue Paul Rimbaud, F-34184 Montpellier Cedex 4Tél.: +33 (0)4 99 23 29 00, fax: +33 (0)4 99 23 29 [email protected]

2. Délégation PACA3, rue Marcel Arnaud, F-13100 Aix-en-ProvenceTél.: +33 (0)4.42.91.64.10, fax: +33 (0)[email protected]

Collectivité territoriale de Corse22, cours Grandval, BP 215, F-20187 Ajaccio cedexTél.: +33 (0)4 95 51 64 64

Communauté d'Agglomération Hérault MéditerranéeZI le Causse, BP 26, F-34630 Saint-ThibéryTél.: +33 (0)4 99 47 48 49, fax: +33 (0)4 99 47 48 50

Commission EuropéenneDG ENV D1, BU 9 02/1, 200 Rue de la loi, B-1049 Bruxelles

Commune de Besse-sur-IssoleHôtel de ville, place Noël Blache, F-83890 Besse-sur-IssoleTél.: +33 (0)4 94 69 70 04, fax: +33 (0)4 94 59 65 57

Commune du Cannet des MauresHôtel de Ville, place de la Libération, F-83340 Le Cannet-des-MauresTél.: +33 (0)4 94 50 06 00, fax: +33 (0)4 94 73 49 61

Commune de Flassans-sur-IssoleHôtel de ville, avenue du Général de Gaulle, F-83340 Flassans-sur-IssoleTél: +33 (0)4 94 37 00 50, fax: +33 (0)4 94 69 78 99

Commune du MuyHôtel de Ville, 4, rue Hôtel de Ville, F-83490 Le MuyTél.: +33 (0)4 94 19 84 24, fax: +33 (0)4 94 19 84 39

Commune de PortiragnesHôtel de Ville, avenue Jean Moulin, F-34420 PortiragnesTél.: + 33 (0)4 67 90 94 44, fax: +33(0)4 67 90 87 00

Commune de ViasHôtel de Ville, 6, place des Arènes, F-34450 ViasTél.: +33 (0)4 67 21 66 65, fax: +33 (0)4 67 21 52 21

Commune de ValliguièresMairie de Valliguières, F-30210 ValliguièresTél.: +33 (0)4 66 37 18 64, fax: +33 (0)4 66 37 36 45

Conseil Général du GardHôtel du Département, rue Guillemette, F-30044 Nîmes cedex 9Tél.: +33 (0)4 66 76 76 76

Conseil Général de l’HéraultHôtel du Département, 1 000, rue d’Alco, F-34087 Montpellier cedex 4Tél.: +33 (0)4 67 67 67 67, fax: + 33 (0)4 67 67 76 41

Conseil Régional du Languedoc-RoussillonHôtel de Région, 201, avenue de la Pompignane, F-34064 Montpelliercedex 2Tél.: +33 (0)4 67 22 80 00, fax: +33 (0)4 67 22 81 92

Conseil Régional de Provence-Alpes-Côte-d’AzurHôtel de Région, 27, place Jules Guesde, F-13481 Marseille cedex 20Tél.: +33 (0)4 42 90 90 90, web site: www.cr-paca.fr

DIREN LR: Direction Régionale de l’Environnement du Languedoc-Roussillon58, avenue Marie de Montpellier, CS 79034, F-34965 Montpellier cedex 2Tél.: +33 (0)4 67 15 41 41, fax: +33 (0)4 67 15 41 15pré[email protected]

DIREN PACA: Direction Régionale de l’Environnement de PACALe Tholonet, BP 120, F-13603 Aix-en-Provence cedex 1Tél.: +33 (0)4 42 66 66 00, fax: +33 (0)4 42 66 66 01pré[email protected]

DIREN Corse: Direction Régionale de l’Environnement de CorseRoute d’Agliani, Montesoro, F-20600 Bastia Tél.: +33 (0)4 95 30 13 70, fax: +33 (0)4 95 30 13 89pré[email protected]

Ecosphère3 bis, rue des remises, F-94100 Saint-Maur-des-FossésTél.: +33 (0)1 45 11 24 30, fax: +33 (0)1 45 11 24 [email protected]

EPHE: Ecole pratique des hautes étudesLaboratoire de Biogéographie et Ecologie des vertébrés, Case 94Université de Montpellier II, place E. Bataillon, F-34095 Montpellier cedex 5Tél.: +33 (0)4 67 14 32 90, fax: +33 (0)4 67 63 33 27

MEDD: Ministère de l’Ecologie et du Développement DurableDirection de la Nature et des paysages, 20, av. de Ségur, F-75302 Paris 07 SPTél.: +33 (0)1 42 19 20 21, web site: www.environnement.gouv.fr

ONF Var: Office National des forêts, Agence Départementale du VarUnité Spécialisée Développement, (A.D. O.N.F. 83)101, chemin de San Peyre, F-83220 le PradetTel: +33 (0)4 98 01 32 50, fax: +33 (0)4 94 21 18 [email protected]

ONF Gard: Office National des Forêts, Agence Départementale du Gard1, impasse d’Alicante, BP 4033, F-30001 Nîmes Cedex 5Tél.: +33 (0)4 66 04 79 00, fax: +33 (0)4 66 38 99 [email protected]

Université d’Aix Marseille III – IMEPInstitut Méditerranéen d'Ecologie et de Paléoécologie - CNRS UMR 6116Université d'Aix-Marseille IIIEuropole méditerranéen de l'Arbois, bâtiment Villemin, BP 80F-13545 Aix-en-Provence cedex 04, FranceTél.: +33 (0)4 42 90 84 06, fax +33 (0)4 42 90 84 48

Pole-relais "Mares et Mouillères de France"Institut Européen du Développement Durable, Centre de Biogéographie-Ecologie66, rue de France, 77300 FontainebleauTél.: +33 (0)1 60 72 19 61, fax: +33 (0)1 60 72 08 [email protected]

Mediterranean Temporary Pools

volume 1

Issues relating to conservation, functioning and management

Editors: Grillas P., P. Gauthier, N. Yavercovski & C. PerennouAssociate editors: Thiéry A., M. Cheylan, C. Jakob, F. Médail, G. Paradis, L. Rhazi, F. Boillot & F. Ruchon

Besnard A. (EPHE), Boillot F. (CBNMP), Boutin J. (CEEP1), Catard A. (CEEP2),Chauvelon P. (TDV), Cheylan M. (EPHE), Duborper E. (TDV), Emblanch C.(université d’Avignon), Félisiak D. (TDV), Gauthier P. (TDV), Genthon S.(AGRN.RH), Grillas P. (TDV), Hébrard J. P. (université d’Aix-Marseille III –IMEP1), Heurteaux P. (CNRS ad., perso. 1), Hugonnot V. (ad. perso. 2), Jakob C.(EPHE et TDV), Lombardini K. (EPHE), Marsol L. (ONF Var), Martin C. (uni-versité d’Avignon), Médail F. (université d’Aix-Marseille III – IMEP2), Paradis G.(université de Corse, ad. perso. 3), Perennou C. (TDV), Pichaud, M. (TDV),Quézel P. (université d’Aix-Marseille III – IMEP, ad. perso. 4), Rhazi L. (uni-versité Hassan II), Rhazi M. (TDV, université d’Aix-Marseille III – IMEP2),Rombaut D. (CEEP2), Ruchon F. (AGRN-RH), Samraoui B. (universitéd’Annaba), Scher O. (université de Provence, Aix-Marseille I), Soulié-Märsche I. (université Montpellier II), Thiéry A. (université de Provence, Aix-Marseille I) and Yavercovski N. (TDV)

AGRN.RH (Genthon S., Ruchon F.)Association de Gestion de la Réserve Naturelle de Roque-Haute, 1, rue de la Tour, F-34420 PortiragnesTél/fax: +33 (0)4 67 90 81 [email protected]

CBNMP (Boillot F.)Conservatoire botanique national de Porquerolles, Castel Sainte Claire,F-83418 Hyères cedexTél: +33 (0)4 94 12 82 30, fax: +33 (0)4 94 12 82 [email protected]

CEEP1 (Boutin J.)Conservatoire Études des Écosystèmes de Provence Alpes du Sud, 890, chemin de Bouenhoure Haut, F-13090 Aix en ProvenceTél: +33 (0)4 90 47 02 01, fax: +33 (0)4 90 47 05 [email protected]

CEEP2 (Catard A., Rombaut D.)Conservatoire Études des Écosystèmes de Provence Alpes du Sud-Var, 1, place de la Convention, F-83340 Le LucTél: +33 (0)4 94 50 38 39 / 06 16 97 82 [email protected]@wanadoo.fr

EPHE (Besnard A., Cheylan M., Jakob C., Lombardini K.)Ecole pratique des hautes études, Laboratoire de Biogéographie et Ecologiedes vertébrés, Case 94, Université de Montpellier II, Place E. Bataillon, F-34095 Montpellier cedex 5Tel: +33 (0)4 67 14 32 [email protected]@[email protected]

ONF Var (Marsol L.)Unité Spécialisée Développement / Agence Départementale du Var del'Office National des Forêts (AD ONF 83), 101, chemin de San Peyre, F-83220 le PradetTél: +33 (0)4 98 01 32 50, ligne directe: +33 (0)4 98 01 32 78, fax: +33(0)4 94 21 18 [email protected] / [email protected]

TDV (Chauvelon P., Duborper E., Félisiak D., Gauthier P., Grillas P, Jakob C.,Perennou C., Pichaud M., Rhazi M., Yavercovski N.)Station Biologique de la Tour du Valat, Le Sambuc, F-13200 ArlesTél: +33 (0)4 90 97 20 13, fax: +33 (0)4 90 97 20 [email protected]

Université d’Aix-Marseille III – IMEP1 (Hébrard J.P.)Institut Méditerranéen d'Ecologie et de Paléoécologie - CNRS UMR 6116,Université d'Aix-Marseille III, Faculté des Sciences et Techniques de Saint-Jérôme, Case 461, F-13397 Marseille cedex 20Tél: +33 (0)4 91 28 85 35, fax: +33 (0)4 91 28 80 51

Université d’Aix Marseille III – IMEP2 (Médail F., Rhazi M.)Institut Méditerranéen d'Ecologie et de Paléoécologie - CNRS UMR 6116,Université d'Aix-Marseille III, Europole méditerranéen de l'Arbois, bâtiment Villemin, BP 80, F-13545 Aix-en-Provence cedex 04Tél: +33 (0)4 42 90 84 06, fax: +33 (0)4 42 90 84 [email protected]

Université de Provence, Aix-Marseille I (Scher O., Thiéry A)E.A. Biodiversité et environnement, Université de Provence, 3, place Victor Hugo, F-13331 Marseille cedex 3Tél: +33 (0)4 91 10 64 25, fax: 04 91 10 63 03 [email protected]

Université d’Avignon1 (Emblanch C.)Laboratoire d’Hydrogéologie, Université d’Avignon et des pays de Vaucluse,F-84000 [email protected]

Université d’Avignon (Martin C.)Laboratoire de Biologie, Université d’Avignon et des pays de Vaucluse, F-84000 [email protected]

Université de Montpellier II (Soulié-Märsche I.)Laboratoire de Paléobotanique - UMR 5554 du CNRS, Université Montpellier II,C.P. 062, Place E. Bataillon, F-34095 Montpellier cedex 5Tél: +33 (0)4 67 14 39 78, fax: +33 (0)4 67 14 30 [email protected]

Université d’Annaba (Samraoui B.)Laboratoire de recherche des zones humides, Université d’Annaba, 4, rue Hassi-Beïda, Annaba, Algé[email protected]

Université Hassan II (Rhazi L.)Faculté des Sciences Aïn Chock, Laboratoire de Biologie et PhysiologieVégétale, BP 5366, Maarif Casablanca, MarocTél.: (212) 037 86 33 10, fax: (212) 022 23 06 [email protected]

ad. perso. 1 (Heurteaux P.)24, rue Pierre Renaudel, F-13200 ArlesTél: +33 (0)4 90 52 09 00, fax: +33 (0)4 90 52 08 [email protected]

ad. perso. 2 (Hugonnot V.)Le Bourg, F-43270 Varennes Saint HonoratTél/Fax: +33 (0)4 71 00 23 [email protected]

ad. perso. 3 (Paradis G.)7, cours Général Leclerc, F-20000 AjaccioTél: +33 (0)4 95 50 11 [email protected]

ad. perso. 4 (Quézel P.)Chemin du Cabrol, F-13360 [email protected]

Acknowledgments The Station biologique de la Tour du Valat would like to warmly thank all theeditors, authors and everyone who collaborated on this volume, as well asMohand Achérar (CEN-LR), Joël Bourideys (DIREN PACA), Christine Bousquet(AME), Jean Boutin (CEEP), Thomas Calvière (TDV), Maddy Cancemy (OEC),Marie-Luce Castelli (OEC), Paul Chemin (DIREN LR), Claire Chevin (MEDD),Béatrice Coisman (CEEP), Natacha Cotinaut (Mairie du Cannet-des-Maures),Geneviève Coutrot (TDV), Daniel Crépin (DIREN LR), Florence Daubigney (TDV),Christian Desplats (CELRL PACA), Aude Doumenge (AGRN-RH), RenaudDupuy de la Grandrive (ADENA), Roger Estève (CELRL PACA), Sabine Fabre(CEN-LR), Mauricette Figarella (DIREN Corse), Guy-François Frisoni (RéserveNaturelle des Bouches de Bonifacio), Jérôme Fuselier (ADENA), StéphanieGarnéro (CEN-LR), Jean Giudicelli (Maison régionale de l’eau, Barjols), DenisGynouvès (ONF Var), Jean-Claude Heidet (CEEP), Claudie Houssard (CEN-LR),Bruno Julien (Commission Européenne), Emilio Laguna (Generalitat deValence, Espagne), Olivier Limoges (Pôle relais Mares et Mouillères), StéphanieLieberherr (CEEP Var), Gilles Loliot (CELRL Languedoc-Roussillon), IsabelleLourenço de Faria (Commission Européenne), Margarida Machado (Universitéd’Algarve, Portugal), Marc Maury (Ecosphère), Leopoldo Medina, OlivierNalbone (ARPE), Georges Olivari (Maison régionale de l’eau, Barjols), EricParent (Agence de l’Eau RMC), Jean-Claude Pic (TDV), Marlène Savelli (OEC),Pierre Quertier (ONF Var), Bertrand Sajaloli (Pôle relais Mares et Mouillères),Nathalie Saur (Agence de l’Eau RMC), Alain Sandoz (TDV), Hassan Souheil(AGRN-RH), Laurine Tan Ham (TDV), Florence Verdier (CELRL LR) and MyriamVirevaire (CNBMP) for their contribution to the LIFE “Temporary Pools” project.

Editors, associate editors, authors and collaborators

Preface

Temporary pools are without doubt some of the most remarkable yet most threatened habitats in theMediterranean region. They comprise an ensemble of highly complex biotopes linked to the major char-acteristics of the Mediterranean climate: the alternation, during the course of a year, of one or moreflooded phases during the cooler seasons with a dry phase, essentially in the summer.

It is in this mosaic of habitats that highly specific, long-established and often residual plant and animalpopulations have become differentiated. Various biological groups - mainly plants but also crustaceansand batrachians - have individualised ensembles of particular genera and species here; others, mean-while, have developed only commonplace or generalist* species.Some of these groups – such as the microarthropods or the arachnids – remain practically unknown,while others, such as the phyllopods, have recently benefited from detailed taxonomic analysis. For overtwo centuries now, botanists have been interested in the higher plants and the bryophytes*. They havealso evidenced, in the vegetation component of these pools, the remarkable analogies existing betweenthe communities of the various Mediterranean regions, thus highlighting the extreme length of timeduring which many of the genera have been present, especially the vascular cryptograms Isoetes,Marsilea and Pilularia.

The adaptive strategies put in place by a number of temporary-pool species to ensure their survival areoften remarkable and complex. From this point of view, these habitats are ideal material for analysingthe impact of drastic ecological conditions on the adaptive or ecological processes occurring in popula-tions which are often reduced and whose habitat is extremely fragmented.

Awareness of the major biological interest of Mediterranean temporary pools is recent and unfortunatelyonly too frequently linked with their progressive destruction: for a long time considered as mere curiosi-ties, they now belong to the priority habitats of the European Union. The increasing degradation, gen-erally anthropogenic in origin, which affect these habitats has resulted in drastic perturbations or evendisappearances, such as at the pools of Grammont, Saint-Estève or Biot in southern France for example.

In these conditions, a comprehensive approach, from the inventory to the drawing-up of a methodologyfor the management and restoration of Mediterranean temporary pools, has proved to be vital. It shouldtake into account the updating of inventories, especially for groups still insufficiently known, and theanalysis of all the kinds of threats currently weighing on these biotopes. This process should result inmedium and long-term monitoring programmes as well as in the awareness-raising of the public anddecision-makers (local authorities, public services, management organisations, etc.) regarding theexceptional natural-heritage and biological interest of these habitats.

It was with this aim in mind that the LIFE European programme was launched in 1999. It has culminatedtoday in this “management handbook” which, for the first time, draws up the balance sheet, analysesthe impact of the threats facing these habitats and puts forward a number of measures to ensure theirconservation in the medium and long term.

Quézel P.

Summary

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2. Biodiversity and conservation issues. . . . . . . . . . . . . . . . . . 11

a. Habitats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

b. Plant species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

c. Amphibians . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

d. Macrocrustaceans . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

e. Insects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

3. Ecosystem and population functioning and dynamics . . . . 34

a. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

b. Hydro-climatic characteristics . . . . . . . . . . . . . . . . . . . 35

c. Vegetation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

d. Amphibians . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

e. Invertebrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

f. Population dynamics and genetics . . . . . . . . . . . . . . . . . 52

4. Threats to Mediterranean temporary pools . . . . . . . . . . . . 61

5. Management and restoration methods . . . . . . . . . . . . . . . 69

a. From site assessment to management plan . . . . . . . . 69

b. Land management and uses . . . . . . . . . . . . . . . . . . . . 76

c. Management of habitats and populations . . . . . . . . . 79

6. Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

a. Why and how to conduct monitoring . . . . . . . . . . . . . 88

b. Hydrological monitoring . . . . . . . . . . . . . . . . . . . . . . . . 90

c. Vegetation monitoring . . . . . . . . . . . . . . . . . . . . . . . . . 94

d. Amphibian monitoring . . . . . . . . . . . . . . . . . . . . . . . . . 98

e. Crustacean monitoring . . . . . . . . . . . . . . . . . . . . . . . . 102

f. Insect monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

7. Education and communication . . . . . . . . . . . . . . . . . . . . . . 105

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

11

Introduction Grillas P.

Introduction

Temporary pools are unusual habitats, neither truly aquatic nortruly terrestrial, where alternating phases of flooding and dryingout, as well as their isolation, favour the establishment of uniqueand diverse plant and animal communities (Box 1). These habi-tats are characteristic of climatic conditions typified by long dryseasons, in the Mediterranean region and also in various parts ofthe world subject to more or less arid climates: Mediterraneanand arid climatic regions of North and South Africa, the Americas(USA, Chile) and Australia. Mediterranean temporary pools arevery variable in size, from the large pools of Provence or thedayas of North Africa (several hectares) to cupular pools a fewtens of centimetres square on rocky substrates (Provence, Sicily,Malta), via isolated pools of a few hundred square metres.

Rich and varied habitats

Temporary pools have a number of ecological characteristics incommon. However, they do not constitute a homogenous groupand they vary considerably depending on the biogeographicaland climatic region (see next chapter). The hydrological regime,soil type, nature of the underlying rocks and physicochemicalcharacteristics of the water play a major role in their ecology. Inthese habitats, subjected to extreme and unstable ecologicalconditions, often isolated and continually alternating between theaquatic and the terrestrial environments, the flora has developedremarkable adaptations for survival: a wide range of differentsizes, growth forms, modes of reproduction and life-historystrategies (Chapter 3). The fauna has also had to adapt to thesame constraints, with the result that these habitats support adiverse genetic heritage of great value: there are many rare specieshere and many have unique ways of life. Hence, amphibiansconstitute a very important group in Mediterranean temporarypools, with many rare or localised species (Chapter 2c). Several

invertebrate groups such as phyllopod crustaceans (Chapter 2d)and some insects (Chapter 2e) are characteristic of temporarypools and are particularly well adapted to the alternating dry andflooded phases.

Regarding temporary wetlands, the European Union Directive92/43/EEC of 21 May 1992 (known as the “Habitats Directive”118),limits the Mediterranean Temporary Pools category to two maintypes of habitat (Box 2) which are given priority: exclusivelyfreshwater* habitats on non-calcareous substrates, and habitatson slightly brackish substrates that are often calcareous.Mediterranean temporary pools on non-calcareous substratesare characterised by their floristic richness and have earned thedescription “floristic gems”54. They are found in the five regionsof the world with a Mediterranean climate, where their vegeta-tion is characterised by species of the genera Isoetes, Marsileaand Pilularia313. On a calcareous substrate, other kinds of vegeta-tion may be found in temporary pools, also including rare speciesof the genera Ranunculus, Damasonium and Elatine.

Vulnerability and threats

Temporary pools are very vulnerable habitats due to their shal-low depth of water and their frequently small surface area.Further, the species which colonise them are often inconspicuousand little known. Despite an improving public perception of wet-lands over recent years, temporary pools are often poorly identifiedand their importance not appreciated, leaving them vulnerable tounintentional destruction. Within the Mediterranean Basin, theconservation of temporary pools has for thousands of years beencompatible with, and even favoured by, agricultural activity. Today,economic conditions along both shores of the Mediterranean areundermining the conditions for their conservation. Modern agri-culture enables these generally flat and only slightly floodedareas to be easily drained to create good agricultural land. Theyare also endangered by industrialisation and the developmentof tourism. A less common threat is their conversion to quasi-permanent water bodies to form reservoirs, for use in flood regu-lation or protection against fire or even to be managed forhunting, fish farming or wildlife conservation.

Objectives and limitations of the management guide

This book has the objective of aiding the conservation ofMediterranean temporary pools by taking into account their rich-ness and their ecological functioning. It is aimed first and fore-most at site managers throughout the Mediterranean region. Itaims to provide them with the information necessary to identifythese habitats, to improve their understanding of their functioningand the ecology of the species which inhabit them and, finally, toenable them to manage and restore degraded sites.

Box 1. The Ramsar definition of temporary pools16

Temporary pools are small (generally <10 ha), shallow wetlandscharacterised by alternating phases of drought and floodingand by very self-contained hydrology. They occur in depressions,which are often endorheic*, that are submerged for sufficientlylong periods of time to allow the development of hydromor-phic soils, aquatic or semi-aquatic vegetation, and specificanimal communities. However, and equally importantly, they dry out for longenough to exclude the more commonplace plant and animalcommunities which are characteristic of more permanent wet-lands.

This definition specifically excludes habitats that are in directphysical contact with permanent water bodies (fringes of lakes,permanent marshes, large rivers, etc.), which generally do notallow the most characteristic species of these habitats todevelop.

Box 2. Mediterranean temporary pools15

Temporary, very shallow water bodies (a few centimetres deep)existing only in winter or at the end of spring, with a semi-aquatic Mediterranean vegetation consisting of therophytes*and geophytes* belonging to the Isoetion, Nanocyperion flaves-centis, Preslion cervinae, Agrostion salmanticae, Heleochloionand Lythrion tribracteati alliances.

12

Mediterranean temporary pools

The book has been produced as part of the LIFE-Nature project,“Conservation of Mediterranean Temporary Pools No. 99/72049”.This project, which is dedicated to Mediterranean temporarypools in southern France, will eventually be named LIFE “Tem-porary Pools”. It draws widely on management experiments car-ried out over the course of this programme, but also on theliterature and the expertise of scientists from a range of disci-plines throughout the Mediterranean region. The analysis of theirecological functioning provides a basis for this discussion. Theguide has therefore been conceived not as a series of directlyapplicable “recipes” but rather as a framework for activities tai-lored to each individual situation. It is supplemented, in the secondvolume, with a series of detailed notes on some important speciesof Mediterranean temporary pools.

The scope of this guide principally covers the European Unionpriority habitats and in particular oligotrophic* temporary pools.However, while the species may be different, the ecological pro-cesses are very similar to those of other types of temporary wet-lands. Many points are therefore equally applicable to othertemporary habitats (pools in brackish conditions, for example)and so examples have occasionally been borrowed from othertypes of temporary pools.

A remarkable temporary pool, the Catchéou pool in the Bois de Palayson(Var, France)

Roch

é J.

Flooding regime

Ephemeral

Episodic

Intermittent

Seasonal

Near-permanent

Predictability and duration of flooding

Filled only after unpredictable rain and by run-off. The floodedarea dries out during the days following the flooding and rarelysupports macroscopic aquatic organisms.

Dry for 9 years out of 10, with rare and very irregular flooding (orwet periods) which may last for a few months.

Alternating wet and dry periods, but at lower frequency than sea-sonal wetlands. Flooding may persist for months or years.

Alternating wet and dry periods every year, in accordance with theseason. Usually fills during the wet season of the year, and dries outin a predictable way on an annual basis. The flooding lasts for sev-eral months, long enough for macroscopic animal and plant organ-isms to complete the aquatic stages of their life cycle.

Predictable flooding, though water levels may vary. The annualinput of water is greater than the losses (does not dry out) in 9years out of 10. The majority of organisms living here will not tol-erate desiccation.

13

2. Biodiversity and conservation issues

a. Habitats Yavercovski N., P. Grillas, G. Paradis & A. Thiéry

Introduction

A “temporary wetland” is a habitat defined by alternating phasesof flooding and drying out, irrespective of the duration or fre-quency of these phases. A wide range of wetlands fall within thisdefinition: the fluctuating fringes of permanent water bodies(lakes, lagoons, ponds, etc.), temporary pools and streams, flood-plains, and also artificially modified habitats such as ricefields orsaltworks. Their distribution is principally determined by climaticcharacteristics (rainfall/evaporation regime), and to a lesser extentby the geomorphology of the site and of its catchment area. Themajority are found in regions subject to a marked alternation ofdry and wet seasons, i.e. in tropical, Mediterranean, arid andsemi-arid climates16, 47 (see chapter 1). There are temporary poolsin practically all the countries of the Mediterranean Basin andtheir islands (see Chapter 2b and Box 3).

Most of the classifications relating to temporary wetlands arebased on the predictability of flooding and its duration (Tab. 1).

Table 1. Simplified classification of temporary wetlands (modified from Boulton & Brock47)

10 years

10 years

10 years

2years

2 years

Jan. Jan.

Temporary pools are known by a wide range of names through-out the world: dayas in Morocco (not to be confused with dayet,a permanent lake), turloughs in Ireland (pools whose water levelvaries with the tide), polje (karstic subsidence basins) in Slovenia,potholes or vernal pools in North America, vleis in South Africa,padule in Corsica, etc. Each of these names reflects different hydro-logical, morphological, geographical and cultural features. Despitethe wide range of environmental conditions to which they aresubjected, certain groups of organisms (plants, ostracod and bran-chiopod crustaceans, amphibians, etc.) are characteristic of tem-porary pools all around the world.There are a number of different classifications for temporarypools. They are distinguished by the relative importance attachedto different classification criteria: duration and frequency of floo-ding, origins, substrate, hydrological regime, physical and chemicalproperties of the water. The CORINE Biotope system34, for exam-ple, is a system for classifying habitats within the European Union,defined on the basis of phytosociological classification of plantcommunities (Box 4). In the Mediterranean, these habitats share two common charac-teristics: • flooding, almost always following rainfall, mostly in autumnand spring, • invariably a period of drying out, which is variable in lengthbut always for several months.Within the general classification of wetlands (Tab. 1) Mediterra-nean temporary pools are associated with seasonal temporarywetlands, i.e. those having a predictable flooding regime.

14


The diversity of Mediterranean temporary pools

Various types of Mediterranean temporary pools may be distin-guished, depending on their origin, the substrate on which theylie, their morphology and their formation. Very different sub-strate types confer specific physicochemical characteristics. Theunderlying substrate may be basic (limestones, etc.) or acid(granite, rhyolite, etc.) and may be compact rock or more or lesspermeable. They may be perched on rocky bars or situated incoastal plains. A proportion of these pools are of natural origin,resulting from various geomorphological processes. However, insome regions, pools of artificial origin, constructed for specificpurposes (watering places for livestock for example), or resultingindirectly from human activities (mineral extraction, etc.), arecommon. Very ephemeral habitats, such as ruts, are not discussedhere, even though organisms which are characteristic of tempo-rary pools, particularly crustaceans, can live in them.

Box 4. Phytosociology, the basis for the classification ofhabitats in the European UnionPhytosociology is the study of plant communities and of the wayin which plant species can be grouped within biotopes with pre-cise ecological and site-specific characteristics. Formulated inparticular by Braun-Blanquet53, 55 during his vegetation studiesin the Mediterranean Languedoc, phytosociology allows a detailedtypology of plant communities to be drawn up. The key elementof phytosociology based on the plant list is the floristic associa-tion, of which several definitions have been proposed; initially inthe strictest sense of the term: “a floristic association is a group-ing of a defined floristic composition which appears in the sameform wherever the same local conditions are found. It is by defi-nition an ensemble of species whose coexistence dependsdirectly on the environment”269, this definition gradually becamebroader: “a floristic association is a unique combination ofspecies of which some, defined as characteristic, are specificallyassociated with the association, the others being defined as com-panion species”176. Barbero24 suggested that “the characteristicspecies are, within a given bioclimatic complex, the species mostintimately linked to a habitat, and sometimes to a complex ofhabitats, where they attain their optimum development”. Thefloristic association, an abstract concept, is represented in thefield by individuals belonging to the association (homogenousplant community observed in the field and belonging to theassociation in question), which may be characterised by com-plete plant lists drawn up for a given area, and considered by thephytosociologist to be homogenous with regard to the flora andthe vegetation.To name an association, the phytosociologist selects one ortwo characteristic or dominant species. The suffix -etum isadded to the root of the genus name of the main, determiningspecies, and the species part of its name is put into the geni-tive case. The second qualifying species is also placed in thegenitive, but its generic name ends in o, i or ae. Hence, theassociation characterised by Isoetes duriaei and Nasturtiumaspera will be named Isoeto duriaei-Nasturtietum asperae. Theassociations are grouped according to floristic affinity intoAlliances, which are themselves collected into Orders.

Based on Quézel & Médail315

Box 3. Temporary pools in Algeria and the Maghreb

In Algeria, temporary pools are the commonest and mostcharacteristic hydrosystems. Among the organisms most typi-cal of these habitats, calanoid copepods (microcrustaceanstraditionally categorised as zooplankton) occupy a prominentposition340. Examples include species which are endemic* toNorth Africa or which have a restricted distribution around theMediterranean Basin, such as Copidodiaptomus numidicus andHemidiaptomus gurneyii. Some calanoids are rare, such asDiaptomus cyaneus, or associated with brackish or saline pools,such as Arctodiaptomus salinus and Arctodiaptomus wierze-jskii. In the Maghreb, many species of water fleas (other micro-crustacea) of the genus Daphnia swarm only in temporarypools.Among aquatic insects, many species have developed strate-gies for survival and breeding (migration, developmental dia-pause*, etc.) that are adapted to the fact that their habitatdries out for long periods. For example, the dragonflies Aeshnamixta, Sympetrum meridionale and Sympetrum striolatummigrate to high mountain woodlands to spend the summermonths. In autumn they leave this refuge and come back downto breed337. The Zygoptera (damselflies) Lestes barbarus andLestes viridis spend the summer around stands of alders, wherethe ambient microclimate protects them from desiccation. Thisextended sexual maturation (3-4 months) allows many speciesto avoid breeding at an unfavourable time338.Amphibians are also adapted to the vicissitudes of theMediterranean climate (precocious breeding among specieswith slow development; delayed egg laying for those with rapiddevelopment). The Algerian Ribbed Newt, Pleurodeles poireti, aspecies endemic to Algeria and Tunisia, depends on temporaryfreshwater pools405, where amphibians generally encounterfewer predators, despite the frequent presence of the LittleEgret, Egretta garzetta, which feeds preferentially in thesehabitats.Since the pioneering work of Gauthier159, few studies havebeen carried out into Algerian pools. However, recently, theLaboratoire de Recherche des Zones Humides (AnnabaUniversity) has carried out a series of studies of the biodiver-sity, structure and functioning of temporary pools. The pre-liminary results suggest that ecological factors such as soiltexture and salinity determine the spatial structure, whiletemporal patterns are closely linked to the seasonal regulationof the various taxa.

Samraoui B.

The drought, which until recently was still considered to be a“terrible catastrophe” for the biological communities of thesehabitats, has, on the contrary, proved to be the most importantfactor in maintaining their biological uniqueness (richness, diver-sification of adaptive strategies, high productivity, resilience,etc.). In all these regions, the vegetation and fauna of the poolsshows similarities, such as the presence of rare pteridophytes(Marsilea spp., Isoetes spp., Pilularia spp.) or the abundance ofphyllopod, cladoceran, ostracod and copepod crustaceans.

15


Pools of natural originThe natural processes leading to the creation of the pools areprincipally erosion and siltation.Erosion may result from the physicochemical action of water(dissolution of limestone for some cupular pools and poljes, withremoval of sediments), from wind action (removal of fine sedi-ments), from geomorphological processes associated with therealignment of watercourses, and also from these processes incombination, perhaps combined with the effects of the fauna oreven the flora49, 263, 380.Natural siltation limiting drainage or run-off may contribute tothe formation of pools (e.g. the series of endorheic* depressionsnorthwest of Benslimane in Morocco, or the pools on the Permiansubstrates of the Plaine des Maures). The origins of temporarypools have important consequences for their richness and theirfunctioning, particularly their hydrological regimes (see chapter3b) and the potential connections between populations of ani-mals or plants (see chapter 3f). A large number of types of natural pools may be distinguishedaccording to their origins. A few characteristic types are describedbelow.

Cupular poolsThese pools, which are small (a few tens of square centimetres orsquare metres) and which have very reduced catchment areas(Box 7), are created by erosion within blocks of bedrock or rocklayers. Their water supply comes entirely from rainfall. Their sedi-ments become extremely desiccated during the dry phase. Thesepools are characterised by a shallow soil and by an inconspicuousvegetation consisting of small and often rare species. They arefound for example in Morocco on the limestone layers of theChaouia380, in Malta on the limestone layers of Kamenitzas21, 223,on the island of Capri in Italy277, and in France on rhyolite in the

Box 5. Mediterranean temporary pools in France An initial inventory, carried out in 2003 in the French Medi-terranean region391, allowed 106 sites to be identified, repre-senting more than 900 temporary pools, the majority relevantto Habitat 3170, “Mediterranean Temporary Pools”. SomeMediterranean temporary pools are found to the north of theMediterranean region (especially Poitou-Charente). Three major types of pools may be distinguished on the basisof the substrate260:• brackish temporary pools of coastal wetlands: Camargue,Basse Crau, coastal fringes of Languedoc, Corsica, • temporary pools of fairly mineralised water, more often thannot on calcareous substrates. These are the pools of the gar-rigues of Languedoc (the garrigues of Montpellier and Uzès, laGardiole, the Causses méridionaux) and, in Provence, theEstagnolet pool at La Barben, the pool on the Cengle plateau,and the pools of the central Var, • temporary freshwater pools, on generally thin soils with asandy or silty texture, poor in humus, with acid pH or weaklyalkaline. In the Provence-Alpes-Côte d’Azur (PACA) Region,from east to west, are to be found: the Biot and Estérel mas-sifs, the Colle du Rouet, the Plaine de Palayson, Plaine desMaures and Plaine de Crau. In Languedoc-Roussillon, from eastto west, lie: the Etang de Capelle, the Costière Nîmoise, theAgde area, the basaltic plateau of Pézenas, the Plaine deBéziers, the plateaux of Roque-Haute and Vendres, the poolsof Saint-Estève and the Plateau de Rodès. In Corsica, fromnorth to south, lie the pools of Cap Corse, the Agriates, thecoast of the southwest, Porto-Vecchio and Bonifacio.

Although they amount to a very small total area (beyond doubtless than 1000 ha), Mediterranean temporary pools support, inFrance, several hundred plant species (see chapter 2b), 14 speciesof amphibians (Chapter 2c), 18 species of anostracan crus-taceans (Chapter 2d) and many species of insects (Chapter 2e).

Yavercovski N., M. Cheylan & A. Thiéry

Box 6. The dayas of Morocco Morocco is considered to be the foremost country in theMediterranean Basin for its richness in temporary pools, locallyknown as dayas. They are widely distributed across the wholeof the country, at low density in the east, the south and at highaltitudes, and at high density in the western coastal zonebetween Tangiers and Tiznit. The degree of flooding decreasesfrom north (six to eight months) to south (one to two months),and from west to east.From a biogeographical point of view, there is a very distinctpredominance of Mediterranean and cosmopolitan species,while Atlantic taxa are poorly represented.In Morocco, the wide range of climatic, geological and geo-morphological conditions is the basis of a remarkable diversityof dayas. Research carried out on crustaceans by Ramdani318

and Thiéry380 has enabled four principal groups of dayas to bedistinguished:

• Dayas of the arid eastern plateaux close to the Algerian bor-der and of the Saharan zones south of the Atlas mountains:confined to plains at altitudes between 900 and 1400 m whichreceive less than 200 mm of irregularly distributed precipita-tion per year, the duration of flooding is from 15 to 75 daysand they may remain dry for several years. They are shallowand, for the most part, of natural origin.• Dayas of the interior arid plains (Jbilets and the Haouz nearMarrakech): situated on plains with an arid bioclimate at 300to 1000 m altitude, receiving 200 to 400 mm of water per year,the flooding period is from 2 to 4 months. The substrate isschistose and produces a clayey soil by weathering. • Dayas of the coastal Atlantic plains (Gharb, Rabat with theCork Oak forests of Mamora, the Benslimane region, fromCasablanca to Settat and Essaouira): in the Atlantic low-alti-tude plains (<500 m) in a sub-humid and semi-arid climate,receiving 400 to 800 mm of water per year, these dayas havea flooded period of between 5 and 7 months. The soil is eitherhydromorphic over a sandstone or schist substrate (Benslimanedayas), or sandy over an impermeable clay layer (Mamoradayas). • Mountain dayas (Middle Atlas, High Atlas, Rif mountains):these are situated at high altitudes (>2000 m) in a humid bio-climate, and receive over 800 mm of water per year, directlyfrom rainfall and indirectly from melting snow. The floodingperiod is from 3 to 6 months. The substrate here is of basalt,dolomitic limestone or Permian-Triassic red sandstone.

Rhazi L.

16


Var (Esterel), on limestone in the Bouches du Rhône (Lamanon),and on granite outcrops in Corsica.

Poljés and dolinesThese pools are created by karstic dissolution and/or subsidence.They form depressions characterised by more or less complexhydrological links with the subterranean karst, and support a veryrich flora and fauna. (cf Box 13, Chapter 3b). They are found for example in France in Provence (central Var),Languedoc (the Lac des Rives on the Causse du Larzac, Valliguièrespool in the Gard), in Corsica (in the Bonifacio limestone: Padulu andMusella pools), in Slovenia (whence their name), and in Morocco, inthe Middle Atlas (limestone plateau of Ain Leuh, Azrou, etc.) and onthe plains of the west, in the south of Benslimane Province.

Pools associated with river dynamics (but not connected with thewatercourse)Close to the main beds of watercourses, these slight depressions,less than one metre deep, may be filled by rainfall and/or fluc-tuations in the water table, depending on the situation. In France,

the pools of the Ile de la Barthelasse at Avignon, and the poolsof Cerisières at the Tour du Valat in the Camargue belong to thistype of formation.

Pools in slight depressions in the land surface These pools occur on impermeable clayey-silty substrates, mostoften isolated from the water table and often shallow. In Corsica(France), the Tre Padule are examples of this type of pool.

Pools of dune systems These pools occupy the slacks between the dunes in active or fossildune systems. They are well developed on the Moroccan coast(Benslimane Province) where consolidated dunes are aligned atright angles to the general slope of the plateaux and form obsta-cles to the flow of watercourses111, 323. They may also be seen onthe Languedoc coast and in Spain.

Pools of artificial origin People have created ponds and pools for use in livestock farming,transport networks, irrigation and water storage. Over time these

Box 7. The cupular pools of the Colle du Rouet

At the Colle du Rouet (Var), cupules, hollowed out in rhyolitictabular formations often form, on the same pavement, systemsconsisting of tens of pools. The presence of connections betweenthe pools imply that they function as communicating basins.Through the action of periodic storms, sediments that accumu-late at the bottom of cupules situated at high levels are carriedaway by the water and may on occasion be redistributed intoneighbouring cupules. This type of functioning would explain:• the maintenance of vegetation of a pioneer* type in the majorityof cupules;• the spread of species from one cupule to another;• the occurrence of very variable water levels and vegetationalstages in different cupules.For the plants and crustaceans of the temporary pools, the effectof storms will therefore be positive to the extent that it counter-acts the threat posed by infilling, but negative when the wholeof the seedbank and all eggs are washed away.In a study of the cupular pools of the island of Gavdos (Greece),small pools (<1 m2 and <50 cm deep) hollowed out in calcareousor ophiolitic rocks, Bergmeier30 found a clear relationship betweenthe depth of the pools, which influences their drying-out date,and their vegetation. He defined five types of pools on this basis:from the more aquatic pools flooded up to May, with Zanichelliaand Callitriche pulchra as characteristic species, to more terres-trial pools, holding water only up to the beginning of March,with Tillea alata and Crepis pusilla.At the Colle du Rouet, the vegetation of 14 cupules situated onthe same rhyolitic surface (Fig. 1) was studied using the quadrattransect method. In each cupule, the plant species richness(range: 1 to 22) was strongly correlated with the mean depth ofthe sediment (range: 1 to 8 cm). A classification of pools carriedout on the basis of pool depth and mean sediment depth revealsfour quite different groups:• shallow cupules (mean 5 cm) with skeletal soils, very species-poor with Crassula vaillantii,

• deep cupules (mean 10 cm) with thin soils, species-poor withCallitriche brutia, Isoetes velata, Crassula vaillantii and a fewamphibious species,• deep cupules with deep soils (>5 cm on average) wet enoughto support perennials such as Isoetes velata, Mentha pulegiumand several small annual rush species (Juncus bufonius, etc.),• shallow cupules with deep soils (2.4 cm on average) with manyspecies and richer in terrestrial species than the other groups.

These cupular pools are populated by invertebrates with short lifecycles166: a few anostracan branchiopods such as Tanymastixstagnalis, cladocerans, ostracods and cyclopoid copepods. As wellas these crustaceans there are a few insects, most commonlyDiptera (larvae of Culicidae, Ceratopogonidae and Chironomidae).In all cases these are migrant insects of unspecialised habitats,described as opportunists.

Pichaud, M., E. Duborper & N. Yavercovski

A system of cupular pools (Colle du Rouet, Var, France)

Cata

rd A

.

17


habitats have been colonised by biological communities whosecomposition and structure change fairly frequently according tothe age of the habitat. Among the wide range of different types,the following may be mentioned:

“Lavognes” on the Causses (Southern France)These watering places for sheep consist of small circular depres-sions with a natural bottom, lined with stone or concrete. Theperiod for which they hold water is very variable from site to site.They can constitute very important habitats in these regions,which are lacking in natural watering places.

Rock extraction sites Temporary pools today fill the holes formed in former quarries bythe excavation of various rocky materials. In France, the pondsamong the limestone peaks north of the Etang de Berre, and theRoque-Haute Nature Reserve with its 205 pools deriving mostlyfrom basalt extraction97, provide examples.

A pool created by basalt excavation at Notre-Dame de l’Agenouillade(Hérault, France)

Roch

é J.

Relative elevation (m)

0 1 2 m

1.8 +

1.8 - 1.7

1.7 - 1.6

1.6 - 1.5

1.5 - 1.4

1.4 - 1.3

1.3 - 1.2

1.2 - 1.1

1.1 - 1

1 - 0.9

0.9 - 0.8

0.8 - 0.7

0.7 - 0.6

0.6 - 0.5

0.5 - 0.4

0.4 - 0.3

0.3 - 0.2

0.2 - 0.1

0.1 - 0

Boundaries of catchment areas

Boundaries of deposits

Overflows

Map

: M. P

icha

ud &

E. D

ubor

per

- St

atio

n bi

olog

ique

de

la T

our

du V

alat

Figure 1. An ensemble of cupular pools on rhyolitic rock layer (Colle du Rouet, Var, France): topographical map

18


Water reservoirs Some pools develop from small reservoirs, used for irrigation (theCatchéou pool in the Var, pools close to villages in Morocco, etc.)or for fire-fighting (Plaine des Maures). In Corsica, in the easternplain, huge reservoirs, almost completely dry from May to Sep-tember, have been built in the valleys and depressions for use inarboriculture as well as sheep and cattle raising. The reservoir atTeppe Rosse, near Aléria, is the most interesting from the pointof view of plant biodiversity. Its gradually sloping banks promotethe establishment of summer species rare in Corsica (Gratiolaofficinalis, Pulicaria vulgaris, etc.), depending upon how muchwater is drawn off for irrigation289, 290.

Storm-water tanks and pollution-control tanks built alongsidemotorways These artificial habitats, whose purpose is to protect againstflooding and pollution, have proved to be veritable hotspots ofbiodiversity, for plants as well as animals (invertebrates andamphibians343, 344, 345). Their substrates may be natural or formedfrom liners with a thin layer of sediment. These sites are goodmodels for use in analysing the effects of pollutants (metals,hydrocarbons, etc.) on living organisms202.

The legislative and institutional framework

The European Directive of 21 May 1992 on the conservation ofnatural habitats and wild fauna and flora118 is more commonlyknown as the Habitats Directive. It classifies as being “of Euro-pean Community Interest” the habitats listed in its Annexe I,among which are distinguished some particularly noteworthy habi-tats, categorised as “priority habitats”. It also lists, in Annexe II,a number of animal and plant species whose habitat should besubject to conservation measures. The member countries of theEU are committed to the protection of the habitats of Annexe Iof the Habitats Directive and the habitats of the species inAnnexe II, through the designation of “Special Areas of Conser-vation” which make up the “Natura 2000 Network”. Among the wide range of temporary pool habitats, some areconsidered by the EU to be particularly important because ofheightened conservation issues associated with the rarity anduniqueness of their animal and plant communities and with theirspecialised ecology. They are grouped within two habitats ofAnnexe I of the Habitats Directive, with the following codifica-tion and description:• Oligotrophic,* weakly mineralised waters on usually sandysoils in the western Mediterranean (Natura 2000 code: 3120),• Mediterranean temporary pools (Natura 2000 code: 3170), ahabitat given priority designation.

The Manual of Habitat Interpretation published by the EU15 givesmore precise definitions and allocates these habitats to basichabitat types, listed together with their characteristic species. InFrance, the basic habitats are the subject of detailed notes in theHabitats Register158, where they are described at their most mostdetailed level, i.e. that of the plant association.

It is important to distinguish the pool, which is an ecological,functional and landscape unit, from the “MediterraneanTemporary Pools” habitats recognised to be of EC-wide interestin the Habitats Directive. In a single pool both the habitat of ECinterest and the priority habitat (3120 and 3170 respectively)may coexist, as is often the case at the Plaine des Maures in the

Box 8. How are the habitats designated as of EC-wideinterest or priority to be identified in a temporary pool?

This simplified key to habitat identification is not a key to theidentification of phytosociological units. However, it shouldenable the site manager to determine whether or not a poolcontains a habitat of EC interest or priority. It applies only tohabitats in mainland France and Corsica (Fig. 2).

The identification of Habitats 3120 and 3170 is based on whetherthe substrate has an acidic or basic character, the length of theflooding period and the composition of the amphibious plantcommunities: the non-exhaustive lists of “key species”, used tocharacterise the habitats, include species belonging to variousregions and to different vegetation units.

1.- Siliceous (acid) substrate, flooding during winter and all orpart of spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 – Substrate neutral or basic lime-rich, delayed drying out(summer or autumn) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.– Flooding limited (saturation), irregular, mostly winter,Serapias grasslands in the crystalline areas of Provence:Habitat 3120: oligotrophic*, very weakly mineralised waterover usually sandy soils of the West Mediterranean (phyto-sociological alliance: Serapion, Aubert & Loisel, 1971). Key species: Serapias spp., Oenanthe lachenalii, Chysopogongryllus, Isoetes histrix.– Flooding more regular and for longer periods, spring or sum-mer amphibious species. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3.– Shallower than 0.4 m, amphibious species growing in earlyspring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4– Deeper than 0.4 m, species growing in late spring or summer:

Habitat 3170: Amphibious Mediterranean grasslandsflooded for long periods (phytosociological alliance: Preslioncervinae Br.-Bl. Ex Moor 1937).Key species: Mentha cervina, Artemisia molinieri, Trifoliumornithopodioides, Oenanthe globulosa.

4.- Groupings dominated by species of the genus Isoetes: Habitat 3170: Mediterranean temporary pools with Isoetes(phytosociological alliance: Isoetion Br. Bl. 1936).Key species: Isoetes spp., Marsilea strigosa, Pilularia minuta,Litorella uniflora, Ranunculus revelieri, Crassula vaillanti.- Grassland dominated by Agrostis pourretii. A little later thanthe Isoetion vegetation, they follow after them over the courseof the season in Corsica291:Habitat 3170: phytosociological alliance Agrostion salmanti-cae Rivas Goday 1958 (= Agrostion pourretii Rivas Goday1958).Key species: Agrostis pourretii, associated with Lythrum borys-thenicum or Illecebrum verticillatum.

19


Var. In addition, Habitat 3170 includes a large number of plantcommunities of which several may sometimes be seen togetheror may succeed one another over time in a single pool, in accor-dance with environmental gradients. Similarly, a pool may includea habitat recognised as being of EC-wide interest by the EU injust a part, small or large, of its area. Finally, in accordance withthe interannual variability of the Mediterranean climate, theplant communities have an equally variable spatial distributionwithin the pool, from one year to another. It may even happen thatsome plant communities of the priority habitat do not appear incertain years. These factors often cause difficulties for the non-specialist inidentifying habitats in the context of the Habitat Directives (Box 8).In each case, management needs to be undertaken on an appro-priate scale, which is at the very least that of the pool, but whichmust often also include its catchment area.

5.- Amphibious species growing in summer and autumn innutrient*-rich, sometimes brackish substrates:Habitat 3170: Mediterranean halonitrophilous amphibiousgrassland (phytosociological alliance: Heleochloion Br.-Bl inBr.-Bl., Roussine & Nègre 1952).Key species: Heliotropium supinum, Crypsis aculeata, Crypsisschoenoides, Cressa cretica. - Amphibious species growing in spring and summer, colo-nising richer, calcareous or basic substrates:Habitat 3170: Mediterranean annual amphibious grassland(phytosociological order: Nanocyperetalia Klika, 1935)Key species: Damasonium polyspermum, Lythrum tribractea-tum, Cyperus flavescens, Cyperus fuscus, Elatine macropoda,Teucrium aristatum.

Yavercovski N. & G. Paradis based on Gaudillat & Haury158

Figure 2. Localisation of habitats of EU interest in Mediterranean continental France and Corsica

Habitats of European community interestSite Diffuse

distribution Serapion ■

Priority habitatsIsoetion ■ Higt densityPreslion ■ ? DisappearedAgrostion ■Heleochloion ■Nanocyperetalia ■

Mediterranean Sea

Perpignan

Narbonne

NîmesArles?

Avignon

Aix en Provence

Nice

Cannes

MarseilleToulon

Bastia

Porto Vecchio

Bonifacio

Ajaccio

Béziers

Montpellier 0 50 km

Map: M. Pichaud & Nicole Yavercorvski - Station biologique de la Tour du Valat

20


b. Plant species Médail F.

Introduction

From the point of view of the flora and the vegetation, oligo-trophic freshwater* temporary pools are classified among the mostbiologically and biogeographically interesting ecosystems in theMediterranean region.The relevant floristic assemblages are mainly distributed in thewestern Mediterranean: Spain330, Balearics238, Portugal201,Morocco49, 263, 323, 326, Algeria76, 77, Tunisia306, southern France260,Corsica242, 260, 291, Sardinia274 and Sicily67, 248. Structurally similarvegetational associations have also been reported from Libya66,mainland Greece and some of the islands of the Aegean Sea30, 31, 126,and more sporadically from Turkey214 where, however, there aresome interesting but little-known areas (cf. the remarkablerecent rediscovery of Pilularia minuta in the Izmir region178), as isalso true of Syria (P. Quézel, pers. com.). While these habitats and plants are well known in some areas, itis for many reasons difficult to obtain a precise idea of the con-servation issues at the Mediterranean level. Unspectacular andephemeral, these habitats have often been under-recorded (espe-cially in the eastern Mediterranean, where information has onlyrecently begun to be obtained); the periods when the plants areabsent during unfavourable years may give the impression thatthey have disappeared, whereas in fact they are still present inthe form of the soil seedbank. These habitats bear the full bruntof human depredations (urban development, drainage, conver-sion to agriculture, eutrophication) and some very valuable areasare becoming rapidly degraded (notably in North Africa). Finally,the functioning of these complex systems remains poorly known,and conservation or restoration activities must rely on a limitedbody of knowledge. It is not easy therefore to produce a thoroughsummary for the whole peri-Mediterranean zone. However, thanksin part to surveys carried out within the LIFE “Temporary Pools”project, satisfactory information regarding temporary pools insouthern France will be available from now on.

Species richness and plant diversity in Mediterraneantemporary pools

Mediterranean temporary pools support plant communities thatare very rich in rare and threatened species. This high biodiver-sity is explained by the functional characteristics and dynamicsof these systems. The unstable conditions and low productivityallow the coexistence of plants that are usually annual, weaklycompetitive and small in size. However, there is a high degree ofspatio-temporal heterogeneity in this diversity and in the floris-tic composition which is closely dependent on variations in thedates of flooding37 (Chapter 3c).The usually positive relationship between number of species andsurface area constitutes one of the oldest laws in ecology andbiogeography*. This relationship has been confirmed for a suite ofmid-European pools283, but not for the north Moroccan dayas323.In addition, temporary pools are generally larger in North Africathan in Europe76: an Isoetes velata pool a kilometre long and ahundred metres wide has, for example, recently been recorded inTunisia. It is also usually agreed that in similar ecological condi-tions the temporary pools of North Africa have a greater floristic

Box 9. Floristic diversity and human activities: theexample of the temporary pools of northwest MoroccoA detailed study of the factors determining the development offloristic diversity was carried out at 30 pools (dayas) inBenslimane Province (Morocco). These pools are heavily influ-enced by people through continual agricultural activities, veryheavy grazing pressure, and their use for washing by the localcommunities. These uses result in pollution by phosphates andby nitrogen-based fertilizer, and eventually in eutrophicationof the water. However, the total floristic diversity of pools isnot significantly different either between pools whose catch-ment area is used for agriculture or forestry or between differ-ent types of use (grazing only or crop growing plus grazing).Among the environmental parameters considered, only pH playsa significant role. The area of the pools has no effect. However,basing the analysis purely on the total number of species givesa poor indication of the effects of human uses, since a veryspecialised suite of rare plants, typical of the pools, is replacedby common plants that are more adapted to human distur-bance (ruderal or generalist* species).Considering only the characteristic pool species, pools in wood-land have more species than those in cultivated areas. Poolswhich are only grazed show a distinctly higher diversity of charac-teristic plants than those in areas which have been cultivatedand then grazed (26 v. 20 species). This diversity increases withincreasing maximum depth of water, the diameter of the waterbody in spring and the duration of flooding, but pH does not playa significant role. The ecosystems present in the area surroundingthe pools also contribute to their floristic richness: the flora ofCork-Oak woodlands accounts for about 14% of the totalspecies richness of woodland pools, and weeds of cultivation forabout 20% of the total species richness of pool surrounded byagriculture. In spite of the major human activities, these dayastherefore conserve a significant series of characteristic species,since the long period of flooding in the centre of the pools gene-rally constrains the degree of access by livestock and the poten-tial for conversion to agriculture. However, rare plants are lesscommon in disturbed pools.

Médail F. and L. Rhazi based on Rhazi323; Rhazi et al.,326; Rhazi et al.327

Damasonium polyspermum and Elatine brochonii, two rare species in adaya in the dry phase (Benslimane, Morocco)

Gril

las

P.

21


diversity than those in Europe. A group of small pools will alsocontain more species and will be more valuable from the natural-heritage point of view than a single pool of equivalent surfacearea283. Even so, a conservation strategy should not of courseneglect larger pools, since the risk of local population extinctionsdecreases with increasing size of their habitats.

Plants dependent on Mediterranean pools: biogeographical aspects

The unique character of the flora of Mediterranean temporarypools derives in the first place from a diverse assemblage ofpteridophytes (Isoetes, Marsilea, Pilularia), often closely confinedto these habitats. Their water requirements are variable. Next tothese are plants that are strictly dependent on flooding, such asspecies of Callitriche or the various aquatic Ranunculus. Amongother well-represented genera, Lythrum, Eryngium and Solenopsismay be mentioned. The distribution of the species of temporary pools is often frag-mented, with populations separated by several hundred kilometres.Should they be seen as the vestiges of a formerly far wider andmore continuous distribution, or as resulting from random disper-sal over long distances by the wind (pteridophyte spores) or bybirds? (Box 26 Chapter 3f). In the absence of any detailed studies,it is at present impossible to answer this biogeographical ques-tion. At all events, the main centre of radiation for the plantspecies under consideration lies in the western part of the Medi-terranean Basin: Quézel313 estimated that fewer than a quarter ofthe species present in the west occur also in the eastern Medi-terranean.In contrast with those in California205, the temporary pools of theMediterranean Basin are characterised by a rather low degree ofplant endemism (17 endemic* taxa , i.e. 17.5% of the total listof species characteristic of the pools: see Tab. 2). There are only afew endemic species, for example Eryngium atlanticum in Morocco,Isoetes heldreichii in Greece, Ranunculus revelieri (Corsica andProvence), Marsilea batardae and Ranunculus longipes (IberianPeninsula), Solenopsis bicolor (Algeria and Tunisia) and Artemisiamolinieri (Provence). The process of speciation has been incompletein a number of cases where various endemic subspecies (8 taxa)have been described (e.g. Isoetes velata, Polygonum romanum,Ranunculus isthmicus, R. revelieri, Solenopsis minuta).The processes whereby these pools have been colonised have clearlybeen complex, and a number of different lineages may be distin-guished: a typically Mediterranean lineage, most frequent, (Dama-sonium, Elatine, Kickxia, Lotus, Lythrum, Trifolium, etc.), a mid-European lineage including Mediterranean-Atlantic taxa (Isoetes,Cicendia, Exaculum, Illecebrum, Littorella, Juncus, etc.), and a tropi-cal plant lineage (Alternanthera, Marsilea, Oldenlandia, Lauren-bergia).

Conservation issues and levels of protection around the Mediterranean

Despite our limited knowledge of the distribution of the charac-teristic plants of Mediterranean temporary pools, a preliminarysynthesis (Tab. 2) has attempted to draw up a list of the rarespecies (country by country). This list is based on information invarious inventories, floras and Red Lists, drawn up at the nationallevel and supplemented by some unpublished data.

This assessment currently includes 108 taxa of specific or sub-specific rank. Spain, France and Italy each have a little over 60%of the total number of species listed; next come Morocco andAlgeria with about 50% of the species. These countries are there-fore of the highest priority as regards conservation issues, bear-ing in mind that it is in the Maghreb that the most criticalanthropogenic threats occur. In the eastern Mediterranean Basinwe note the fairly large number of plants recorded for Greece (42taxa, i.e. 39% of the total), the result of surveys carried out

Box 10. Important conservation issues affecting bryophytes* Mediterranean temporary pools and marshes are importantbiotopes for bryophytes, especially Hepaticae (liverworts).However, only Riella (Riella helicophylla [see species notes], R. affinis, R. cossoniana, R. parisii, R. notarisii, R. numidica, R. bialata, etc.) are strictly dependent on these habitats. Thesetaxa depend fundamentally on the flooding/drying regime tocomplete their development cycle. Around the poolsSphaerocarpos texanus is also found, a fairly close taxonomicrelative of Riella but with different ecology. Although liver-worts of the genus Riccia are not strictly confined to the areasaround temporary pools, this is nevertheless a favoured habi-tat for them. About twenty species of Riccia (see speciesnotes), may be observed in these situations (Riccia macro-carpa, R. michelii, R. beyrichiana, R. canaliculata, R. perennis,R. crystallina, etc.). The coexistence of many species in thisgenus at one locality is an important factor when one isattempting to assess the natural heritage value of a site. OtherMarchantiales such as Oxymitra incrassata and Corsiniacoriandrina are the typical inhabitants of the bottoms and sur-roundings of temporary depressions that are in the process ofdrying out. Fossombronia species (F. angulosa, F. crozalsii, F. pusilla, F. husnotii, etc.) are equally well represented. Theleafy liverworts, such as Gongylanthus ericetorum, are, gener-ally speaking, less well represented in these habitats. Theanthocerotes are fairly frequent (Anthoceros agrestis,Phaeoceros bulbiculosus, P. laevis, etc.).There are also many tiny mosses in temporary pools. ThePottiaceae, a major family in the Mediterranean region, areespecially well represented by the genera Phascum, Pottia,Acaulon, Weissia, Tortula, etc. The Funariaceae (Funariamicrostoma or the genus Entosthodon, including E. obtusus,E. mouretii), species of the genus Bryum (Bryum alpinum, B. barnesii, B. bicolor, B. gemmiparum, B. klinggraeffii, B. pal-lens, B. tenuisetum), many members of which have effectivemethods of vegetative reproduction*, are generally abundant.The Ephemeraceae, minute and very delicate species, may alsocolonise the areas around temporary pools. Archidium alterni-folium (Archidiaceae) may form large colonies in some tempo-rary pools. There are many bryophyte species in these habitats which arerare at the national scale or around the whole of theMediterranean, but through lack of knowledge they are notgenerally cited in lists of species of conservation concern or ofprotected species. Riella helicophylla is an exception to therule in that it is subject to various designations (see speciesnotes), including citation in Annexe II of the Habitats Directive.

Hugonnot V. & J.P. Hébrard

22


66 49 66 68 9 8 11 42 16 34 23 17 18 20 18 31 58 58

Agrostis pourretii Willd. Poaceae RAiropsis tenella Poaceae RR

Alternanthera sessilis (L.) R. Br. Amaranthaceae E?Antinoria insularis Parl. Poaceae V VU RRApium crassipes (Koch) Reichenb. fil. Apiaceae ENApium inundatum (L.) Reichenb. Fil. Apiaceae RR

• Artemisia molinieri Quézel, Barbero et Loisel Asteraceae E EBaldellia ranunculoides (L.) Parl. Alismataceae CR AC• Benedictella benoistii Maire Fabaceae I ICallitriche brutia Petagna Callitrichaceae ACCallitriche lenisulca Clav. Callitrichaceae RRCallitriche lusitanica Schotsm. Callitrichaceae RCallitriche naftolskyi Warb. & Eig Callitrichaceae

Callitriche palustris L. Callitrichaceae ENCallitriche platycarpa Kütz Callitrichaceae VUCallitriche pulchra Schotsman Callitrichaceae ENCallitriche truncata Guss. subsp. occidentalis Callitrichaceae

Callitriche truncata Guss. subsp. truncata Callitrichaceae R RR RR R?

Cardamine parviflora L. Brassicaceae VU RR

• Centaurium bianoris (Sennen) Sennen Gentianaceae

Cicendia filiformis (L.) Delarbre Gentianaceae RR• Coronopus navasii Pau Brassicaceae CRCrassula vaillantii (Willd.) Roth. Crassulaceae RR ARCyperus hamulosus M. Bich Cyperaceae RDamasonium bourgaei Coss. Alismataceae EN V ACDamasonium polyspermum Coss. Alismataceae CR RRElatine alsinastrum L. Elatinaceae DD RRR RR RRElatine brochonii Clavaud Elatinaceae VU E RR R• Elatine gussonei (Sommier) Brullo et al. Elatinaceae R CR RElatine macropoda Guss. Elatinaceae CR RR RR RR• Eryngium atlanticum Batt. & Pitard Apiaceae V VEryngium corniculatum Lam. Apiaceae

• Eryngium galioides Lam. Apiaceae

Eryngium pusillum L. Apiaceae E RR R RRExaculum pusillum (Lam.) Caruel Gentianaceae RR RGlinus lotoides L. Molluginaceae ? E? RHeliotropium supinum L. Boraginaceae EX? ? ACIllecebrum verticillatum L. Illecebraceae RRIsoetes duriei Bory Isoetaceae R• Isoetes heldreichii Wettst. Isoetaceae V VIsoetes histrix Bory Isoetaceae EX? AC• Isoetes olympica A. Br. Isoetaceae

Isoetes setacea Lam. Isoetaceae V RR• Isoetes velata A. Braun subsp. intermedia (Trabut) Maire & Weiller Isoetaceae RR RR• Isoetes velata A. Braun subsp. perralderiana Isoetaceae

Isoetes velata A. Braun subsp. tegulensis Batt. & Trabut Isoetaceae RR RRIsoetes velata A. Braun subsp. velata Isoetaceae V VU AC R?Isolepis setacea (L.) R. Br. Cyperaceae V R KKickxia cirrhosa (L.) Fritsch Scrophulariaceae ? RRR R?Kickxia commutata (Reichenb.) Fritsch subsp. commutata Scrophulariaceae ? AC ACLaurenbergia tetrandra (Schoot.) Kanitz in Martius Haloragaceae RRR• Legousia juliani (Batt.) Briq. Campanulaceae

Limosella aquatica L. Scrophulariaceae ? RRLittorella uniflora (L.) Ascherson Plantaginaceae VU RRLotus angustissimus L. Fabaceae RR RRLotus conimbricensis Brot. Fabaceae AR AC• Lythrum baeticum Silvester Lythraceae EN RLythrum borysthenicum (Schrank) Litv. Lythraceae RRR R ACLythrum thesioides M. Bieb. Lythraceae V EWLythrum thymifolium L. Lythraceae V ? R RLythrum tribracteatum Salzm. ex Sprengel Lythraceae V AC ACMarsilea aegyptiaca Willd. Marsileaceae RR• Marsilea batardae Launert. Marsileaceae I CR VMarsilea minuta L. Marsileaceae E? RRMarsilea quadrifoliaL. Marsileaceae CR V VUMarsilea strigosa Willd. Marsileaceae V VU RMentha cervina L. Lamiaceae V DD RR RRMolineriella minuta (L.) Rouy Poaceae AC• Morisia monanthos (Viv.) Ascherson Brassicaceae VMyosotis sicula Guss. Boraginaceae ? R ACMyosurus minimus L. Ranunculaceae RR RRMyosurus sessilis S. Watson Ranunculaceae

Myriophyllum alterniflorum DC. Haloragaceae VU R RR

• Nananthea perpusilla (Loisel.) DC. Asteraceae V LR• Oenanthe lisae Moris Apiaceae

Oldenlandia capensis L. fil. Rubiaceae RR E? ROphioglossum azoricum C. Presl. Ophioglossaceae V LROphioglossum lusitanicum L. Ophioglossaceae RR ROphioglossum polyphyllum A. Braun Ophioglossaceae RRR RRPilularia globulifera L. Marsileaceae EN CR ?Pilularia minuta Durieu ex A. Braun Marsileaceae VU V VU VU RR RR• Polygonum romanum Jacq. subsp. gallicum (Raf.) Raf. & Vill. Polygonaceae

Pulicaria sicula (L.) Moris Asteraceae CC RRPulicaria vulgaris Gaertn. Asteraceae ? RRRanunculus batrachioides Pomel Ranunculaceae VU RRRanunculus isthmicus Boiss. subsp. isthmicus Ranunculaceae LR RR• Ranunculus isthmicus Boiss. subsp. tenuifolius Ranunculaceae R RRanunculus lateriflorus DC. Ranunculaceae V VU ? RR R R• Ranunculus longipes Lange ex Cutanda Ranunculaceae

Ranunculus ophioglossifolius Vill. Ranunculaceae EX? AC• Ranunculus revelieri Boreau subsp. revelieri Ranunculaceae V V E• Ranunculus revelieri Boreau subsp. rodiei (Litard.) Tutin Ranunculaceae V VRanunculus saniculifolius Viv. Ranunculaceae ? RRRanunculus trilobus Desf. Ranunculaceae EX?• Solenopsis balearica (E. Wimm.) Aldasoro et al. Campanulaceae VU• Solenopsis bicolor (Batt.) Greuter & Burdet Campanulaceae RSolenopsis laurentia (L.) C. Presl. Campanulaceae AR• Solenopsis minuta (L.) C. Presl subsp. annua Greuter, Matthäs & Risse Campanulaceae R R• Solenopsis minuta (L.) C. Presl subsp. corsica Meikle Campanulaceae

Solenopsis minuta (L.) C. Presl subsp. minuta Campanulaceae

• Solenopsis minuta (L.) C. Presl subsp. nobilis (Wimm.) Meikle Campanulaceae ETeucrium aristatum Pèrez Lara Lamiaceae R R ETeucrium campanulatum L. Lamiaceae EN RR RTrifolium cernuum Brot. Fabaceae R?Trifolium ornithopodioides Oeder Fabaceae

Verbena supina L. Verbenaceae ? AR ACWahlenbergia lobelioides (L. fil.) Link subsp. nutabunda (Guss) Murb. Campanulaceae VU E RR

Rare vascular plants of Mediterranean temporary pools Families Char. Intern. protec. UICN 1997

Cro

atia

Gre

ece

Alb

ania

Mal

ta

Ital

y

Port

ugal

Fran

ce

Spai

n

Cyp

rus

Turk

ey

Syri

a

Leba

non

Isra

el

Egyp

t

Lybi

a

Tuni

sia

Alg

eria

Mor

occo

Berne C.

HD II et IV

HD II et IV

Berne C., HD II et IV

Berne C.

Table 2. List of the rare and generally characteristic vascular plants (flowering plants and pteridophytes) of Mediterranean temporarypools (Médail, unpublished)

• Mediterranean endemics*vulnerable-threatened species according to their global distribution area, their population number and present threats

Indications of the categories of threats sensu IUCN395 or rarity according to National Red Data Books and Red Lists or plant guides.International protection: Berne C.: Berne Convention or “Convention relating to the conservation of the wildlife and the natural environment in Europe” of19 September 1979; HD: Habitats Directive of 21 May 1992118.General source of data: Med-Checklist170 and Flora Europaea392 for the European area of the Mediterranean region, supplemented by the following plant guides and publica-tions: Spain and the Balearics: Castroviejo71 and indications of IUCN criteria based on Dominguez Lozano119 ; France: Médail et al.260 and indications of IUCN criteria based onOlivier et al.285 ; Italy: Pignatti299 and indications of IUCN criteria based on Conti et al.87 ; Malta: indications of IUCN criteria based on Lanfranco222 ; Greece: Economidou126 andBergmeier & Raus31, indications of IUCN criteria based on Phitos et al.297 ; Cyprus: Meikle262 ; Turkey: Davis102, Davis et al.103 ; Syria-Lebanon: Mouterde276 ; Israel: rarity criteriabased on Shmida et al.358 ; Egypt: Boulos45, 46 ; Libya: Brullo & Furnari66 ; Tunisia: Pottier-Alapetite307 ; Algeria: rarity criteria based on Quézel & Santa316 ; Morocco: rarity cri-teria based on Fennane & Ibn Tattou138 and Rhazi (unpublished.). The chorology of Damasonium is based on the work of Rich & Nicholls-Vuille329.

23


mainly over the last decade, and to a lesser degree for Turkey (34 taxa). The countries of the Near East and especially the Balkanssupport a fairly limited share of species, perhaps due to under-recording. Nevertheless, some are of the very highest degree ofconservation importance (e.g. Callitriche naftolskyi in Israel andSyria). The importance of some of the large Mediterraneanislands, notably Corsica and Sardinia, should also be stressed. Onthe other hand, pools have suffered from significant impacts orhave locally disappeared on other islands such as Malta and Sicily,where the richest areas now appear to be confined to varioussatellite islands (Pantelleria, Lampedusa, Favignana, etc.) thathave been less affected by humans.Based on their overall range and on information about the rarityof the various species in different countries, it is possible to pro-duce a preliminary list of 38 of the rarest and most threatenedplants of temporary pools around the Mediterranean perimeter(Tab. 2). Among these taxa, Benedictella benoistii, endemic to north-west Morocco, has not been seen for several decades. Severalpteridophytes characteristic of the pools (Pilularia minuta, P. glo-bulifera, Marsilea minuta, M. strigosa, Isoetes setacea) are alsoseriously threatened at the majority of their sites. In North Africa,the status of a number of taxa of tropical origin (Alternantherasessilis, Laurenbergia tetrandra, Marsilea minuta, M. aegyptiaca andOldenlandia capensis), which are highly localised in the form of bio-geographical isolates, is currently completely unknown. FurthermoreCallitriche and Elatine appear to be threatened across their range.Priority for conservation should in the first instance be given tovery localised endemic plants such as Artemisia molinieri, Lythrumbaeticum, Legousia juliani, Solenopsis balearica and/or Coronopusnavasii. At the international level, the plants of temporary pools are stillsubject to very limited and clearly inadequate protection measures.Only four taxa are listed in the Habitats Directive118: Marsilea

Box 11. The role of charophytes* in temporary pools Charophytes are green plants which resemble macrophytesand which are attached to the substrate by rhizoids*. These pio-neer* plants quickly form a dense submerged vegetation knownas “charophyte meadows”. They are of considerable importancein the functioning of temporary pool ecosystems, where theirdry biomass may reach 400 to 500 g/m2 (130). These carpets ofplants provide shelter and egg-laying sites for invertebratesand fish. It is common to see “swarms” of ostracod eggs laid inthe shelter of the whorls of the charophytes.

The Characeae are eaten by many invertebrates (crustaceans,amphipods and molluscs). In lakes they also provide food forfish, crayfish and some birds, for example Red-crested Pochard(Netta rufina)398 and may form up to 90% of the diet ofAnatidae177. Charophytes also provide an indirect dietaryresource; the thalli provide a surface covered with thousandsof epiphytes which are grazed by invertebrates.

The Characeae as a whole are found over a wide range ofphysicochemical conditions, from slightly acid to stronglyalkaline water, with a pH range from 6 to 9.5. Their tempera-ture tolerance ranges from the boreal zone to the equator,depending on species. Species of the genus Chara play a partin the carbonate cycle through the massive incrustations oftheir thalli with microcrystalline calcite and through the calci-fication of their gyrogonites*130, 390. They also contribute signifi-cantly to the oxygenation of the water401.

Characeae are able to survive in temporary habitats thanks totheir oospores* which, uniquely in the plant world, are spiral-shaped. In many species the oospores become calcified duringthe lifetime of the plant and are then known as gyrogonites.The gyrogonites allow species to be identified in the “seed-bank”, including rare species360. Charophytes are known fromas long ago as the Upper Silurian (420 mya) thanks to fossilgyrogonites.

Dispersal is carried out mainly by birds, which carry the gyro-gonites not only in their plumage but also in their digestivetrack. Passage through a duck’s gut in no way affects the via-bility of the gyrogonites309. This is why bird migration routesfrom Scandinavia to southern Europe are “signposted” with achain of lakes in which the boreal species Nitellopsis obtusa isfound. During the Holocene wet phases when there were suit-able lake habitats in North Africa, this chain extended as far asSudan and Senegal, where gyrogonites characteristic of N. obtusacan be found in the fossil state213, 270, 359.

Charophytes are still too frequently neglected in the manage-ment of wetland habitats although their role as a structuralfactor has been recognised by many ecologists. CharophyteRed Lists already exist for many European countries, Australiaand Japan348, 351, 364, 416. It is now vital that France follows theexample of these countries and acts to create a CharophyteRed List and takes efficient measures for the protection ofthese plants.

Soulié-Märsche I.

Artemisia molinieri, a species endemic to a few pools of the Centre-Var(France)

Roch

é J.

24


Agrostis pourretii Willd.Airopsis tenella (Cav.) Asch. & GraebnerAnagallis arvensis L. subsp. parviflora (Hoffm. & Link) ArcangeliAnagallis minima (L.) E.H.L. Krause (= Centunculus minimus)Antinoria insularis Parl.Apium crassipes (Koch) Reichenb. fil.Artemisia molinieri Quézel, Barbero et LoiselCallitriche brutia PetagnaCallitriche truncata Guss. subsp. occidentalis (Rouy) Br.-Bl.Callitriche truncata Guss. subsp. truncataCardamine parviflora L.Chaetonychia cymosa (L.) SweetCicendia filiformis (L.) DelarbreCrassula vaillantii (Willd.) Roth.Crypsis aculeata (L.) AitonCrypsis schoenoides (L.) Lam.Damasonium polyspermum Coss.Elatine brochonii ClavaudElatine alsinastrum L.Elatine macropoda Guss.Eryngium barrelieri Boiss.Exacullum pusillum (Lam.) CaruelGlinus lotoides L.Gratiola officinalis L.Heliotropium supinum L.Illecebrum verticillatum L.Isoetes duriei BoryIsoetes histrix BoryIsoetes setacea Lam.Isoetes velata A. Braun subsp. velataIsolepis cernua (Vahl) Roemer & Schultes (= Scirpus savii Seb. & Mauri)Isolepis setacea (L.) R.Br. (= Scirpus setaceus L.)Juncus bufonius L.Juncus capitatus WeigelJuncus pygmaeus L.C.M. RichardJuncus tenageia L. fil.Kickxia cirrhosa (L.) FritschKickxia commutata (Reichenb.) Fritsch subsp. commutataLittorella uniflora (L.) AschersonLotus angustissimus L. subsp. angustissimusLotus angustissimus L. subsp. suaveolens (Pers.) O. Bolos & VigoLotus conimbricensis Brot.Lotus pedonculatus Cav.Lythrum borysthenicum (Schrank) Litv. (= Peplis erecta, P. hispidula)Lythrum hyssopifolia L.Lythrum thesioides M. Bieb.Lythrum thymifolium L.Lythrum tribracteatum Salzm. ex SprengelMarsilea strigosa Willd.Mentha cervina L.Mentha pulegium L.Moenchia erecta (L.) P. Gaertner, B. Meyer & Scherb. s.l.Molineriella minuta (L.) RouyMontia fontana L. subsp. chondrosperma (Fenzl) Walters (= M. minor C.C. Gmelin)Morisia monanthos (Viv.) AschersonMyosotis sicula Guss.Myosurus minimus L.Myosurus sessilis S. WatsonMyriophyllum alterniflorum DCNananthea perpusilla (Loisel.) DC.Oenanthe globulosa L. Ophioglossum azoricum C. Presl.Ophioglossum lusitanicum L.Pilularia minuta Durieu ex A. BraunPolygonum romanum Jacq. subsp. gallicum (Raffa.) Raffa. & VillarPulicaria sicula (L.) MorisPulicaria vulgaris Gaertn.Radiola linoides Roth.Ranunculus lateriflorus DC.Ranunculus nodiflorus L.Ranunculus ophioglossifolius Vill.Ranunculus revelieri Boreau subsp. revelieriRanunculus revelieri Boreau subsp. rodiei (Litard.) TutinSisymbrella aspera (L.) Spach s. l. (= Nasturtium asperum (L.) Boiss.)Solenopsis laurentia (L.) C. Presl. Solenopsis minuta (L.) C. Presl. subsp. corsica MeikleTeucrium aristatum Pèrez LaraTrifolium angulatum Waldst. & Kit.Trifolium ornithopoides OederTriglochin bulbosum L. subsp. laxiflorum (Guss.) Rouy Verbena supina L.Veronica acinifolia L.Veronica anagalloides Guss.

Table 3. Characteristic plants of the temporary pools ofMediterranean France; based on Médail et al.259, modified andadded to

batardae, M. quadrifolia, M. strigosa and Riella helicophylla, anda revision of the Red Lists is also necessary (Boxes 10 and 11).Inclusion in Red Lists or official protection decrees is very incon-sistent between countries, and an improved prioritisation at theMediterranean level of the threats facing these species, based onthe current criteria of the IUCN395, is clearly required. At the pre-sent time, the latest IUCN Global Red List408 only takes 11 taxa intoaccount, and there are many major omissions. At the nationallevel, the rare books or Red Lists available (Spain, France, Israel,Italy, Malta) highlight the vulnerability of a large number of theseplants, with the exception of that for Greece297, which includesonly Callitriche pulchra and Pilularia minuta (Tab. 2).

Figure 4. Localisation of the important temporary pools for vas-cular plants in Corsica, grouped into five main sectors (based onLorenzoni & Paradis, in Médail et al.260). Ephemeral pools, with avery small surface area and present in various places below theridges of Cap Corse, in Les Agriate and in the north of Porto-Vecchio, have not been indicated.

2827

2625

2423

21

22 201918

17

1615

1413

1211 10

9

87

65 4

32

1

•

•

•

Ajaccio

Bonifacio Lavezzi Islands

Bastia

Saint Florent

•

Cap Corse:1: Capandola

Agriate: 2: shooting range at Casta3: Taglia Carne (Malfalcu)

Around Porto-Vecchio: 4: north of the Etang d’Arasu5: Mura dell’Unda6: Alzu di Gallina7: Muratellu8: Padulellu

Bonifacio area: 9: Tre Padule

and Padule Maggiore (Suartone) 10: Rondinara 11: Tre Padule de Frasseli 12: pools to the southeast of Frasselli 13: Padulu and Paraguano pool14: Musella and east of Musella 15: Cavallo Island 16: Lavezzu Island

Southwest coast: 17: Tonnara 18: Ventilegne19: Testarella 20: Capineru 21: Chevanu 22: Arbitru 23: Tour d’Olmeto and Furnellu 24: Capu di Zivia 25: Cala di Barbaju 26: Senetosa 27: Salina 28: Canusellu

25


Noteworthy plants of temporary pools Protection

Agrostis pourretii Willd. PACA x x x x xAiropsis tenella (Cav.) Asch. & Graebner x x 0? x x x xAntinoria insularis Parl. Corsica - Red data book x x x xApium crassipes (Koch) Reichenb. fil. x x x 0?Artemisia molinieri Quézel, Barbero & Loisel Nat - livre rouge xCallitriche truncata Guss. subsp. occidentalis (Rouy) Br.-Bl. 0? 0Callitriche truncata Guss. subsp. truncata xCardamine parviflora L. 0Cicendia filiformis (L.) Delarbre PACA x x 0 x x x x xCrassula vaillantii (Willd.) Roth. PACA, LR 0? x x x 0? x x x xCrypsis schoenoides (L.) Lam. x x x x x x xDamasonium polyspermum Coss. Nat x x x 0 x x xElatine brochonii Clavaud Nat - Red data book xElatine macropoda Guss. LR 0 x 0? 0?Eryngium pusillum L. Nat - Red data book xExaculum pusillum (Lam.) Caruel PACA x x 0 0 x x 0 x x xGratiola officinalis L. Nat x x x x 0 x 0 x xHeliotropium supinum L. LR x x x 0 0 0? x x xIsoetes histrix Bory Nat 0? x 0 x xIsoetes setacea Lam. Nat - Red data book 0 0 x x x xIsoetes velata A. Braun subsp. velata Nat - Red data book x x 0 0 x x x x x xKickxia cirrhosa (L.) Fritsch Nat x x x x x xKickxia commutata (Reichenb.) Fritsch subsp. commutata Nat 0? x x x 0? x x x x x x xLittorella uniflora (L.) Ascherson Nat 0? x xLotus conimbricensis Brot. PACA, LR x 0? x 0 x 0? x x x xLythrum thesioides M. Bieb. Nat - Red data book x 0?Lythrum thymifolia L. Nat - Red data book x x x x x 0 x x x x x x xLythrum tribracteatum Salzm. ex Sprengel Nat - Red data book x x x x x x x xMarsilea strigosa Willd. Nat - Red data book 0 x x xMentha cervina L. PACA - Red data book x 0? 0 0 x 0 xMolineriella minuta (L.) Rouy Nat x x xMorisia monanthos (Viv.) Ascherson Nat - Red data book x xMyosotis sicula Guss. LR x x X x x x xMyosurus sessilis S. Watson x 0? x x x x xNananthea perpusilla (Loisel.) DC. Nat - Red data book xOphioglossum azoricum C. Presl. Nat - Red data book x x x x x xOphioglossum lusitanicum L. PACA, LR x x x 0 x x xPilularia minuta Durieu ex A. Braun Nat - Red data book 0? x x x x xPolygonum romanum Jacq. subsp. gallicum (Raf.) Raf. & Vill. Lang. x x x x xPulicaria sicula (L.) Moris PACA, LR 0? 0? 0? x x x x xPulicaria vulgaris Gaertn. Nat. x x 0 0 x x x x x x x x xRanunculus lateriflorus DC. Nat - Red data book 0 x xRanunculus nodiflorus L. Nat - Red data book xRanunculus ophioglossifolius Vill. Nat x x x x x x x x x xRanunculus revelieri Boreau subsp. revelieri Nat - Red data book x x x xRanunculus revelieri Boreau subsp. rodiei (Litard.) Tutin Nat - Red data book x xSolenopsis laurentia (L.) C. Presl. PACA 0? x x 0? x x x x xSolenopsis minuta (L.) C. Presl. subsp. corsica Meikle x xTeucrium aristatum Pèrez Lara Nat - Red data book xTrifolium angulatum Waldst. & Kit. 0 0Trifolium ornithopodioides Oeder LR 0 0 x 0? 0? 0?Triglochin bulbosum L. subsp. laxiflorum (Guss.) Rouy Nat x x x xVerbena supina L. PACA x 0?

Provence - Côte d'Azur Languedoc - Roussillon Corsica

Table 4. List of vascular plants, rare, protected or threatened, present within the 20 zones studied in Mediterranean France (based onMédail et al.260, supplemented by the data of Lewin235, Jeanmonod203 and INFLOVAR195)

Protection (Decrees of 20/01/1982 and 31/08/1995): National: protected species throughout the national territory; PACA: protected species inProvence–Alpes-Côte-d’Azur; Corsica: protected species in Corsica; Languedoc-Roussillon: protected species in Languedoc-Roussillon; Red Data Book:species included in “Red Data Book of the threatened flora of France, priority species”285.Status: X: taxon currently present at the studied site; 0?: taxon not seen for over 10 years at the studied site; 0: taxon probably disappeared from thestudied site.

Conservation issues and levels of protection inMediterranean France

Of the 83 plant species characteristic of temporary pools inFrance (Tab. 3 et 4), 53 are considered to be threatened in all orpart of their French range (Tab. 4). These are mostly protectedspecies (44 taxa in total) whether at a national level (28 taxa)or on the Regional scale in Corsica (1 taxon), Languedoc-Roussillon (9 taxa) or Provence-Alpes-Côte d’Azur (10 taxa). It is also to be noted that 20 taxa are listed in the Red Bookof the threatened plants of France, priority species285, whichillustrates the magnitude of the conservation issues regardingthese species and their habitats in Mediterranean France.Based on data available in the literature and provided by fieldsurveys, 20 “key areas” of the French Mediterranean havebeen selected for their richness in characteristic plants oftemporary pools, 15 on the mainland and 5 in Corsica (seeMédail et al.,260 for descriptions of the various areas) (Tab. 4,Fig. 3).

The present status of the plant communities of Mediterraneanpools gives much more cause for concern in mainland Francethan in Corsica (Tab. 4). In Corsica (Fig. 4), the overall conser-vation status of these communities appears to be fairly satis-factory at present apart from the pools of the eastern plain,which have mostly been destroyed or drained, such as thosewith Eryngium pusillum at Vix or those with Pilularia minutanorth of Aléria and near the Tour de Vignale. These examples,admittedly still in a minority, suggest that the degradation oftemporary pools can take place quickly at low altitudes andon the coast. The temporary pools of southern Corsica are veryrich, with 60% of French rare characteristic species recorded260.The conservation issues in the Bonifacio and Porto-Vecchioareas are particularly acute and are notable in the Mediter-ranean Basin context242, 291.On the mainland, three groups of pools have practically dis-appeared or have been profoundly altered by humans: theSaint-Estève pool (Pyrénées-Orientales) has been converted intoa permanent pond11; the series of depressions of the Costière

26


Nîmoise (Gard) were drained and brought under cultivation, thencompletely destroyed during the 1970s; the flooding of theGrammont pool (Hérault) has hastened the disappearance of itscharacteristic species including Isoetes setacea230. In the Alpes-Maritimes, urban pressures encroach further each day onto theBiot Massif, and Pilularia minuta has not been seen for somedecades at its solitary site. In 50% of cases in MediterraneanFrance (Tab. 4), taxa characteristic of temporary pools are cate-gorised as having disappeared (0) or not having been seen for over10 years (0?) at the site in question. However, due to the adap-tations of these plants to spatio-temporal environmental varia-tions, care must always be taken before stating that they havecompletely disappeared from a site. The example of the recentrediscovery of Marsilea strigosa, Isoetes setacea, Lythrum thymi-folia and L. thesioides near the destroyed Saint-Estève pool under-lines the key role of the soil seedbank in assuring the medium- orlong-term survival of these species.

c. Amphibians Cheylan M.

Introduction

The life cycle of amphibians is characterised by a larval stage whichmakes them dependent on an aquatic habitat, with the exceptionof some species which are able to give birth to fully developedyoung (the Black Salamander, for example). This aquatic phase isthe first stage of their life, and very different from the terrestriallife of the adults. The larvae of anurans (tadpoles) go through aspectacular metamorphosis resulting in significant morphologi-cal and physiological transformations: the development of pul-monary respiration, the growth of legs, resorption of the tail andthe transition from herbivorous feeding to an insectivorous regime.This larval stage, which is variable in length, is a key stage for thesurvival of amphibians, hence the importance of breeding sites fortheir conservation. It is all the more important if the amphibiansare only found at a limited number of sites.

Among the numerous aquatic sites in the Mediterranean region,only a few can be used by amphibians. The eggs and larvae are verysensitive to disturbance and predators, which limits the choice ofbreeding sites. Though some species can reproduce in fast-flowing

ITALY

SPAIN

Mediterranean SeaPerpignan

Béziers

Montpellier

NîmesAvignon

Arles

Aix-en-Provence

Marseille

Toulon

0 100 km

Cannes

Nice

1: Biot Massif; 2: massifs of the Estérel and the Colle du Rouet and the Plaine de Palayson; 3: Plaine des Maures;4: pools of the Centre-Var; 5: Plaine de Crau; 6: Etang de la Capelle; 7: Costière Nîmoise; 8: Grammont pool; 9: Agde region; 10: Plateau de Pézenas; 11: Plaine de Béziers; 12: Plateau de Roque-Haute; 13: Plateau de Vendres;14: St-Estève pool and surroundings; 15: Plateau de Rodès.

Figure 3. Localisation of 15 determinant temporary pool areas for vascular plants, in Mediterranean continental France (based on Médailet al.260, modified)

27


water (Salamanders, Euproctus), most seek calm waters, usuallyisolated from the hydrographic network. As a result, temporarypools are preferred breeding places as they are usually isolatedand contain few predators (fish, water snakes, birds). These habi-tats are also favourable from a thermal point of view, and rich inthe phyto- and zooplankton consumed by larvae. Unlike fast-flowing water, the pools also provide abundant aquatic vegeta-tion, favourable to egg laying. For all these reasons, most speciesonly reproduce in the Mediterranean region in pools, and usuallyonly in temporary pools. These habitats are thus essential for thesurvival of this group. The breeding cycles show to what extentamphibians have adapted to these habitats, notably through thesynchronism between egg laying and submersion periods, whichare very irregular in the Mediterranean region (see Chapter 3d).

The conservation issues remain poorly understood, notably inthe southern and eastern Mediterranean. There are still very fewnational or thematic studies, apart from some recent studies19, 121,

302, 355. Attempts at more global approaches are often restricted tosingle European countries85, 91, 192, 225 and there are no Mediterra-nean action plans for the conservation of amphibians as there arefor plants108 or wetlands13. Thus on the basis of the documentsavailable, it is difficult to identify the issues from a geographicalpoint of view, apart from for a very specific region or country.

The threats to temporary pools are numerous (see below andChapter 4). In this context, amphibians are excellent bio-indicators.They are sensitive to physical disturbances in the habitat (declinein breeding sites) as well as to chemical (pollutants, fertilisers,etc.) or biological (trampling by animals, introduced species, etc.)disturbances. In addition, they are bio-indicators of the terres-trial habitat surrounding the breeding site. Damage to one ormore components of the system quickly leads to losses of speciesor populations.

Our knowledge of the biology of Mediterranean species remainslimited. Numerous questions remain unanswered, for example aboutthe factors triggering breeding or the terrestrial life of the ani-mals (dispersal distance, type of refuge used, habitat sought,etc.). Important questions can also be asked regarding the viabilityof populations: what is the distance needed between subpopula-tions in order for a species to be maintained on a given territory?What exchanges take place between pools? What is the mini-mum effective number* for an isolated population? Furthermore,very few conservation or restoration experiments have been con-ducted, other than the research on Triturus cristatus within thecontext of the LIFE “Temporary Pools” project (see Boxes 26 and50) and the research carried out in the Balearics on Alytesmuletensis332.

What kinds of temporary pools are used by amphibians?

Reservoirs, large watercourses and brackish lagoons are rarely ifever occupied by amphibians. Apart from those, amphibiansmake use of very diverse sites: coastal ponds rich in macrophytes,dune slacks, dayas, watering places, natural depressions on rockyground, wadis in the process of drying out, artificial basins, aban-doned quarries, etc. The temporary nature of the sites is a key factor (see Chapter 3d)for many Mediterranean amphibians. Of the 71 species recorded

in the west of the Basin, 14 species are virtually totally depen-dent on temporary pools, and temporary pools are the preferredbreeding habitat for 25 species (53% of all species, Tab. 5). Mostspecies breeding in temporary pools prefer an open or lightlywooded habitat. The presence of livestock is therefore usuallyfavourable for them.

Richness and diversity of communities

The Mediterranean Basin has been recognised as a global biodi-versity “hotspot”38, 279, 314 but its batrachian richness remains lowbecause of the climatic conditions, which are unfavourable forthis zoological group. With 78 species, this fauna occupies anaverage position with regard to species richness, on a par withthe southwest USA. Compared with tropical regions, this richnessis characterised, given an equal number of species, by a greaternumber of genera and families. Maximum richness peaks ataround 50°N latitude156 i.e. outside the Mediterranean zone(northern France and southern Germany). In the MediterraneanBasin, the species richness of amphibians decreases from west toeast, in relation to the aridity gradient: 71 species in the west v. 14 in the east78. The countries richest in species are situated inthe northwest of the Basin: Spain and the Italian peninsula with25 species, France and Portugal with 18 species, then the Balkans(11 to 16 species) and finally the Maghreb (7 to 11 species) (Tab.5). The islands have fewer species (maximum 8 species inSardinia, minimum 1 in the Balearics if introduced species areexcluded). Considering only species dependent on temporarypools, the maximum richness occurs in the western Iberianregion (22 species), followed by the Italian region (13 species),

Juvenile Triturus marmoratus in a pool with Isoetes setacea and Marsileastrigosa (Roque-Haute Nature Reserve, Hérault, France)

Jako

b C.

28


URODELES

Proteidae Proteus anguinus NU VU B1+2bc, C2a II,IV

Salamandridae Salamandra salamandra A S VU NTSalamandra corsica A SSalamandra algira A NT1

Salamandrina terdigitata NUChioglossa lusitanica NU VU A2c II, IV VU KTriturus cristatus I LR/cd II,IV VTriturus carnifex I IV ITriturus karelinii I IVTriturus marmoratus D IV V LC NTTriturus pygmaeus D VU NT 4

Triturus alpestris (incl. cyreni) I VUTriturus vulgaris ITriturus boscai D LC NTTriturus helveticus D S LC KTriturus italicus D IVEuproctus asper NU IV R NTEuproctus montanus A IV REuproctus platycephalus A CR A1ac, B1+2bcd IVPleurodeles waltl D NTPleurodeles poireti D

Plethodontidae Speleomantes italicus NU IVSpeleomantes ambrosii NU II,IVSpeleomantes strinatii NU II,IV 2 RSpeleomantes genei NU LR/nt II,IVSpeleomantes flavus NU VU C2b, D2 II,IVSpeleomantes supramontis NU LR/nt II,IVSpeleomantes imperialis NU LR/nt II,IV

ANURANSDiscoglossidae Discoglossus pictus (incl. auritus) I IV I I(lc)

Discoglossus scovazzi IDiscoglossus galganoi I IV LC NTDiscoglossus jeanneae I II, IV NTDiscoglossus sardus I II,IV R RDiscoglossus montalentii A VU A2c, B2c+3d, C2a II,IV RAlytes obstetricans I IV I NT NTAlytes dickhillenii A VU B1+2cd VUAlytes maurus IAlytes muletensis A CR B1+2bc II+,IV CRAlytes cisternasii I IV NT NT

Bombinatoridae Bombina variegata (incl. pachypus) I II,IV V

Pelobatidae Pelobates fuscus D IV MPelobates syriacus I IVPelobates cultripes D IV V NT NTPelobates varaldii D

Pelodytidae Pelodytes punctatus D V M LCPelodytes ibericus D DD NT

Bufonidae Bufo bufo (incl. spinosus, verrucosissimus) I S LC NTBufo mauritanicus I I (nt)Bufo viridis D IV V I (vu)Bufo brongersmai IBufo calamita D IV S LC NT

Hylidae Hyla arborea I LR/nt IV NT NTHyla intermedia (= H. italica) I IV3

Hyla sarda I IV3 SHyla meridionalis I IV S NT NT I

Ranidae Rana dalmatina A IV S ? ENRana italica A IVRana graeca A IVRana latastei A LR/nt II,IV MRana iberica NU IV VU NTRana lessonae (incl. bergeri) A IV I? IRana shqiperica ARana epeirotica ARana kl. esculenta (incl. hispanica, maritima) A VRana bedriagai (= R. levantina) A IRana kurtmuelleri (= R. balkanica) A I?Rana cerigensis ?Rana cretensis ARana kl. grafi IRana perezi I V S LC NT IRana saharica (incl. riodeoroi) IRana ridibunda V I I

Exotic species Rana catesbeiana I I I

total indigenous species: 71 18 6 (7?) 25 5 8 14 16 14 16 11 14 15 3 25 18 1 11 9 7species exclusive to the territory 0 3 5 0 5 0 0 0 0 0 0 1 1 2 0 1 3 0 0introduced species 5 (6?) 1? 1 0 1 0 0 0 0 0 0 0 0 3 0 3 0 0 0

Impo

rtan

ce o

f poo

ls

UIC

N c

ateg

orie

s (2

001)

Hab

itats

dire

ctiv

e

Fran

ce m

ainl

and

Cors

ica

Ital

y m

ainl

and

Sici

ly

Sard

inia

Slov

enia

Croa

tia

Bosn

ia-H

erze

govi

na

Serb

ia

Mac

edon

ia

Alba

nia

Gre

ece

Cret

e

Spai

n m

ainl

and

Port

ugal

Bale

aric

s

Mor

occo

Alge

ria

Tuni

sia

Table 5. List of amphibians present in the north and southwest of the Mediterranean region (Cheylan & Geniez, unpublished)

Importance of temporary pools for species: D: determinant, I:important, A: not essential, NU: not used.IUCN world categories (version 2001395): CR: seriously threatened with extinction, VU: vulnerable, LR: low riskRed Data List categories France256: E: Endangered species, V: vulnerable, R: rare, I: indeterminate status, S: surveillance necessary.Red Data List categories Spain302: DD: insufficient data, CR: critically endangered species, EN: endangered, VU: vulnerable, NT: near threatened, LC: leastconcernRed Data List categories Portugal141: V: vulnerable species, R: rare, I: indeterminate status, K: insufficiently known, NT: not threatened.Categories for Italy (Environment Ministry): M: threatenedI: Introduced species

Endemic species

1. Spanish possessions in Morocco 2. as sub species of ambrosii 3. as sub species of arborea 4. as sub species of marmoratus + priority HD species

29


North Africa (12 species) and the Balkans (10 species). The faunaof the islands contains few species, in accordance with their sur-face area (Tab. 6). At a local scale (from 10s to 100s of km2), the species richnesscan be given for four regions: • In Provence, an inventory of 16 pools in the centre and southof the Var département (Joyeux A., pers. com.) revealed a speciesrichness of between 3 and 6 species (average: 4.5), for a total of7 species in the whole of the area studied. • In Languedoc, an inventory of 11 temporary pools in the Mont-pellier region and 16 pools in the Roque-Haute Nature Reservenear Béziers enabled the species richness to be estimated in twodistinct geographic sectors. In the first sector, the number of speciesbreeding in a given year in a pool oscillates between 3 and 7,with an average value of around 5.09, for a total of 9 species inthe whole of the zone sampled72. In this area there is a singlepool containing 7 species, a record number for the region. At Roque-Haute, the number of species oscillates between 2 and 5 per pool,for an overall total of 7 species. The average number of speciesis between 3.12 (1996) and 3.5 (1997), and around 10 pools areneeded to obtain all the species present in a given year200.• In Andalusia (Spain), Diaz-Paniagua116 compiled an inventoryof 15 temporary pools in the Doñana Nature Reserve. In this region,the average number of species per pool is 4.6 (min 2, max 7) andbetween 8 and 10 pools are needed to obtain the 10 species pre-sent in the area studied. • In Morocco, El Hamoumi127 compiled an inventory of an ensem-ble of temporary wet habitats (dayas, gueltas, temporary pools)in the region of Mamora and the Merja Sidi Boughaba. In this case,the average number of species per breeding site was 2.6 (min 1,max 4) and between 4 and 6 pools were needed to obtain the 6 species present in the region. Only Rana saharica was missingfrom this inventory, in accordance with its preference for wells inthis part of Morocco. From these few figures, it can be deduced that on average 10 poolsare needed to “capture” all the species present in a given region.A small number of sites are thus sufficient for all the species to berepresented. Occasionally, one to two pools can contain almost allthe species but these are exceptional cases, due to particularlyfavourable habitat conditions: a large structurally diverse pool,with no aquatic predators and a long submersion period withbrief but regular dry periods. At Doñana, Diaz-Paniagua115, 116

showed that it is the largest and most perennial pools that con-tain the most species, which is confirmed by the data of Jakob etal.197, 198 at Roque-Haute in the Hérault and by Alcazar & Beja6 insoutheast Portugal. For the latter authors, there is also a signifi-cant relationship between the length of the hydroperiod* and thenumber of natural-heritage species, which tallies with the obser-vations made in the French Mediterranean region.The different submersion periods of pools often enable a largernumber of species to coexist. Generally speaking, an ensemble ofsmall pools with varied water regimes seems preferable to onesingle large pool. This diversity of water regimes and ecological con-ditions (surface area, depth, etc.) gives more stability to the systemby enabling greater regularity of breeding for the various species.

Distinctiveness of the fauna, biogeography* and endemism

The Mediterranean batrachian fauna is highly distinctive, proba-bly due to geographical complexity (numerous islands, peninsulas,mountainous zones) as well as the isolation of this biogeographical

region compared with the hotspots of tropical diversification sit-uated to the south of the Sahara and in southeast Asia. • Species endemism here reaches 58.7%, which is higher thanmost other botanical and zoological groups (50% in vascularplants312, 44% in freshwater fishes95, 46% in butterflie188, 17% inbirds38) with the exception of reptiles79 (62%). The main hotspotsof endemism are found in the Iberian Peninsula with 13 endemicspecies out of a total of 30 (43.3%), in Corsica-Sardinia with 9 species out of 12 (75%), in the Italian peninsula with 9 speciesout of 25 (36%), in North Africa with 7 species out of 13 (53.8%),then in the Balkans with 6 species out of 22 (27.3%). Crete andthe Balearics only have one endemic species and Sicily none. In theNear East, 3 species out of 14 are endemic, i.e. 21% endemism. Ifjust the species linked to temporary pools are taken into consid-eration, the classification is only slightly modified (Tab. 6). In thiscase, it is the Corsica-Sardinia region which comes first (66.6%)followed by North Africa (58.3%), western Iberian region (36.3%),the Italian region (23%) and finally the Balkans (10%). • The taxonomic diversity of amphibians is also high, with 19 genera, 10 families and two orders, i.e. 4.3%, 22.2% and66.6% respectively of the global total. The best-represented families are Discoglossidae with 73.3% ofglobal species (11 out of 15), Pelodytidae with 66.6% of globalspecies (2 out of 3), Salamandridae with 35.8% and Proteidae with16.6% of global species. As regards the genera, 7 of the 19 generapresent in the Mediterranean region are strictly endemic: Disco-glossus, Chioglossa, Euproctus, Salamandrina, Pleurodeles, Proteusand Speleomantes, and several are mainly found here: Pelodytes,Pelobates, Alytes, Mertensiella and Triturus. Of these, many belongto ancient lineages with a high natural-heritage value. This is thecase with: the genus Pleurodeles, which comprises two speciesbelonging to a very primitive group of Salamandrids22; the genusEuproctus, comprising one species in the Pyrenees, one in Corsicaand one in Sardinia; the genus Chioglossa, which is distinctlyrelictual, with only one species in the northwest of the IberianPeninsula; the genus Discoglossus, endemic in the Mediterranean,with a marked species differentiation in the Iberian Peninsula andthe Tyrrhenian islands; the genus Pelobates, sole representativeof the family in Europe, with four species more or less exclusiveto the Mediterranean region; the genus Pelodytes, sole genus inthe family Pelodytidae, today comprising three species of whichtwo are Mediterranean and one Caucasian; the genus Alytes, com-prising five species distributed in the west of the Mediterranean,sometimes with very limited ranges such as the Mallorcan MidwifeToad, the Moroccan Midwife Toad and the Cisternas Midwife Toad

Discoglossus sardus, an amphibian endemic to the French and ItalianTyrrhenian islands

Chey

lan

M.

30


found in the southwest of the Iberian peninsula. Several of theseancient lineages are in a phase of decline, i.e. comprising veryfew species, sometimes only one, often geographically localisedand generally monotypic: Proteus, Salamandrina, Chioglossa,Euproctus and Pleurodeles. Others, on the other hand, are diver-sifying (Speleomantes, Discoglossus, Alytes), which shows that theprocesses of adaptive radiation do not only involve younger lineages(the genera Rana, Hyla, Triturus for example).

Main threats

On the global scale, a rapid and worrying decline of certain am-phibian populations has been observed since the 1980s7, 68, 180, 193.It has become manifest in very diverse regions sometimes untouchedby human activity: Australia393, Costa Rica237, the former USSR216

and the Pyrenees251. The causes of this decline remain largelyunexplained68. Numerous hypotheses have been put forward: cli-matic changes, epidemics, acidification of habitats, increase ofUV-B radiation and the introduction of exotic species, and thesehypotheses are undoubtedly not mutually exclusive, as indicatedby most recent studies. Up until now, this global decline has only been observed locallyin the Mediterranean region: in the Ebro Delta (Santos pers.com.), the Central System in Spain252, 288 and in Portugal6. On theother hand, a study in Languedoc has shown that amphibian popu-lations have remained stable over the last 25 years98. The imple-mentation of biological monitoring thus seems essential, as hasbeen carried out in several regions of the world72.

Conservation issues and protection measuresfor the western Mediterranean

Table 5 presents an up-to-date list of the amphibians present insouthern Europe and North Africa. This list is based on an updatedcompilation, hence the appearance of taxa not listed in someguides. The position of some taxa in the classification has not yetbeen unanimously accepted and this list could thus be modifiedin the future. To the 39 species mainly (25 species) or exclusively(14 species) dependent on temporary pools, two species can beadded which have recently become established in the region: Ranacatesbeiana introduced in 1932 in the Mantova region of Italyand Rana ridibunda introduced into southern France in the 1980sand now in a phase of expansion.

Of these 39 species, 30 merit particular attention due to theirrarity or to the threats which they face (Tab. 7). Six of them canbe considered as priority species at the Mediterranean scale: • Triturus cristatus is only represented by two isolated popula-tions in southern France, one of which is situated in a zone under-going urbanisation63. • Pleurodeles poireti is endemic in Tunisia and eastern Algeria. Itis a species with a poorly known status, but appears to be threat-ened in a part of its range (Samraoui, in Morand272). • Discoglossus jeanneae occupies the eastern half of the IberianPeninsula. Its populations are fragmented and in low numbers inthe main part of its range apart from in western Andalusia wherethe species is still abundant (Martínez-Solano and García-París,in Pleguezuelos et al.302). • Alytes maurus is an endemic Moroccan species, known at only19 sites in the extreme north of the country (Rift mountain, BouNaceur massif and Jbel Tazzeka)43. • Pelobates cultripes is endemic in Iberia and southern Francewhere it occupies a fairly wide area. It is a species which is cur-rently in decline, both in the Iberian Peninsula (Tejedo & Requesin Pleguezuelos et al.302) and southern France. In this latter region,it is known in only 100 or so sites (Cheylan and Thirion, in Duget& Melki121) and has disappeared from several localities over thelast 20 years. • Pelobates varaldii is only found in Morocco, in the form of dis-continuous populations situated on the Atlantic coast, from Larachein the north to Oualidia in the south99. It occupies very populatedzones, in which the pressures of urbanisation have alreadycaused the disappearance of several populations (Thévenot, pers.com.).

With regard to legislation and the recognition of real conserva-tion status, amphibians are still insufficiently taken into accountdespite the considerable progress made in recent years. The IUCNGlobal Red List396 only includes two species with a wide distribu-tion, not threatened on the global scale (Triturus cristatus and Hylaarborea), and does not include endemic taxa with very limiteddistribution such as Pelobates varaldii or Pleurodeles poireti. TheHabitats Directive118 includes 22 species in Annexe IV and 4 speciesin Annexe II: Bombina variegata, Discoglossus jeanneae, D. sar-dus and Triturus cristatus. During a seminar on re-establishmentprojects for amphibian and reptile species held at El Hierro, CanaryIsles, in October 1993, a group of experts meeting under the aegisof the permanent committee of the Berne convention establisheda list of species in need of restoration plans85. The species included

area (km2)561 800141 500221 300597 90025 5008 700

23 80032 5008 3304 934

number of species22131012433321

numb. of endemic species8317000200

endemism (%)36,423,110,058,30,00,00,066,70,00,0

Western Iberian regionItalian regionBalkansMaghrebSicilyCorsicaSardiniaCorsica-SardiniaCreteBalearics

Table 6. Species richness and levels of endemism in the main biogeographical sectors of the western Mediterranean (species solelydependent on temporary pools)

31


for the western Mediterranean were the following: Triturus cris-tatus, T. italicus, T. karelinii, Alytes obstetricans (in southernSpain, actually considered as a separate species: Alytes dickhil-lenii), Pelobates fuscus insubricus and Bufo viridis. On a national scale, Red Lists have been established in a numberof countries (France, Spain, Portugal, Italy) but only Spain302 hasproduced a reference work calling for objective criteria and moredetailed knowledge of the status of species. Comparison of theSpanish and Portuguese lists reveals disparities which can be putdown more to differences of assessment than to differences instatus. Harmonisation of criteria for all the Mediterranean coun-tries would seem to be essential.

Conservation issues and protection measures in Mediterranean France

The French Mediterranean region supports 24 indigenous amphi-bians and three introduced species, currently spreading in theregion (Tab. 8). Of these 24 species, at least 14 can be consideredas vulnerable or threatened due to very reduced distribution, adecline noticed in recent decades or real threats to habitats. Fourspecies are now particularly in danger: three closely linked totemporary pools (the Crested Newt, the Yellow-bellied Toad andPelobates cultripes) and one less specifically linked (the AgileFrog).

• The Crested Newt was fairly common in the lower Rhône val-ley at the beginning of the 20th century. It is today known atonly five sites, two recently discovered south of Valence (Blache,pers. com.), one in the Ardèche and two in the lower Rhône valley63.Of these five populations, only one is currently the subject ofconservation measures (Valliguières in the Gard), thanks to theinclusion of the site in the Natura 2000 network (See box 26Chapter 3f). • The Yellow-bellied Toad is a species in severe decline through-out most of its range, and particularly in the French Mediterra-nean region where it was abundant less than a century ago254.Today, it only survives in the central Durance Valley (20 or so sitesin the Embrun-Gap sector14 and in certain parts of the highArdèche and the Diois90. For the moment, it is not the subject ofany conservation measures. • Pelobates cultripes is more widespread, with more than 70 breeding sites in Languedoc, 30 or so in Provence and somesites in the lower Ardèche and southern Drôme. It is nonethelessa threatened species, due to the specificity of its habitats and avery long larval cycle. In Provence, it disappeared from severalknown sites in the 1970s-1980s, in particular in the Var and theVaucluse. Fifteen sites are the subject of conservation measures,including several included in the LIFE “Temporary Pools” project:Catchéou and Gavoty pool in the Var, Etang de Valliguières in theGard, Roque-Haute Nature Reserve in the Hérault80. • The Agile Frog has a relict distribution in southern France. InProvence, it is only found in the crystalline massifs of the Maures,the Esterel and the Rouet and their immediate surroundings (amainly Permian depression). In Languedoc, it is only found in theforest of Valbonne in the Gard and in the west of the MontagneNoire, in the Aude and the Tarn (Revel, Castelnaudary, Mazamet).It is primarily a woodland species, dependent on old broad-leaved forests: Cork Oak, Downy Oak, and Chestnut. Its popula-tions appear fairly stable but given their isolation, the frequencyof forest fires and possible competition with the invasive speciesRana ridibunda, their future is not assured.Among the species classified as vulnerable, some can be locallyendangered. This is the case with Alytes obstetricans in LowerProvence (Var and Bouches-du-Rhône) and Discoglossus sarduson the Ile du Levant.

With regard to the conservation issues, great disparities can beobserved between the three regions, with an overall satisfactoryconservation status in Corsica and a poor conservation status inProvence and Languedoc. In the latter two regions, the coastalzones are the most affected; the habitats they provide are oftendegraded or in the process of becoming so. The abandonment offarmland is very marked, which contributes to the loss of biodi-versity and the transformation of natural areas into artificialareas. Our state of knowledge does not really enable zones withamphibian conservation issues to be prioritised from a geographi-cal point of view. Nonetheless, some sites have emerged: thePlaine des Maures - Bois de Palayson - Plateau de Besse - Flassanscomplex in the Var, the Alpilles and the Camargue in the Bouches-du-Rhône, the Causse d’Aumelas and Roque-Haute in the Hérault,the pool at Opoul and around Salses in the Pyrénées-Orientales.In Corsica, the status of amphibians can be considered as satis-factory, despite concerns for Euproctus and the Green Toad374.Aquatic habitats are overall in a good state of conservation, evenif threats exist to temporary pools, notably in certain coastal sec-tors subject to growing urbanisation.

Triturus marmoratus D 1Triturus pygmaeus D 1 1Triturus boscai D 1Triturus helveticus D 1Triturus italicus D 1 1Pleurodeles waltl D 1 1Pleurodeles poireti D 1 1Pelobates fuscus D 1 1Pelobates cultripes D 1 1Pelobates varaldii D 1 1Pelodytes punctatus D 1 1Pelodytes ibericus D 1 1Bufo viridis D 1 1 1 1 1 1 IBufo calamita D 1Triturus cristatus I 1Triturus carnifex I 1 1 1Triturus karelinii I 1 1Triturus alpestris (incl. cyreni) I 1 1 1Triturus vulgaris I 1 1Discoglossus pictus I I 1 1Discoglossus scovazzi I 1 1Discoglossus galganoi I 1 1Discoglossus jeanneae I 1 1Discoglossus sardus I 1 1 1Alytes obstetricans I 1Alytes maurus I 1 1Alytes cisternasii I 1 1Bombina variegata (incl. pachypus) I 1 1 1 1Pelobates syriacus I 1Bufo bufo (incl. spinosus, verrucosissimus) I 1 1 1 1Bufo mauritanicus I 1 1Bufo brongersmai I 1 1Hyla arborea I 1 1 1 1Hyla intermedia (= H. italica) I 1 1 1Hyla sarda I 1 1Hyla meridionalis I 1 1 1 IRana kl. grafi I 1 1Rana perezi I 1 1 IRana saharica (incl. riodeoroi) I 1 1

22 8 13 3 10 1 12 7 4 3 1 2 0

Wes

tern

Iber

ian

regi

on

Ende

mic

s

Ital

ian

regi

on

Ende

mic

s

Balk

ans

Ende

mic

s

Mag

hreb

Ende

mic

s

Sici

ly

Cors

ica-

Sard

inia

Endé

mic

s

Cret

e

Bale

aric

s

Pool

s im

port

ance

Table 7. List of amphibians which could be considered asthreatened in the western MediterraneanD: Very important; I: Important

URODELES

Salamandridae

Salamandra salamandra A

Salamandra corsica A

Triturus cristatus D LR II,IV

Triturus marmoratus D IV

Triturus helveticus D

Euproctus asper NU IV

Euproctus montanus A IV

Plethodontidae

Speleomantes strinatii NU II, IV 2

ANURANS

Discoglossidae

Discoglossus pictus I IV I

Discoglossus sardus I II, IV

Discoglossus montalentii A VU II, IV

Alytes obstetricans D IV

Bombinatoridae

Bombina variegata I II, IV

Pelobatidae

Pelobates cultripes D IV

Pelodytidae

Pelodytes punctatus D

Bufonidae

Bufo bufo I

Bufo calamita D IV

Bufo viridis D

Hylidae

Hyla sarda I IV 3

Hyla meridionalis I IV

Ranidae

Rana dalmatina A IV

Rana lessonae bergeri A IV I ?

Rana bedriagai I

Rana kurtmuelleri I ?

Rana kl. grafi I

Rana perezi I V

Rana ridibunda V I I

total indigenous species 15 14 6 (7)

total vulnerable species 6 5 3

total threatened species 3 2 0

not threatened species 6 7 3

Pool

s im

port

ance

Cors

ica

Lang

uedo

c

Prov

ence

Hab

itats

Dire

ctiv

e

UIC

N c

ateg

orie

s (2

001)

32


Initiatives committed-to or ongoing

For the moment, there are no concerted initiatives at the Medi-terranean level in favour of amphibians. Nonetheless, some coun-tries are committed to conservation initiatives, which are ambitiousto a greater or lesser extent. This is the case with Spain, whichhas just produced a Red Book of the reptiles and amphibians ofSpain302 which describes the current status of species on a nationaland regional scale. For each species, there is information detailingthe reasons behind the attribution of its national status (basedon IUCN methodology), the biological factors important for itsconservation, the threats, and an inventory of the more threatenedpopulations. One chapter summarises the current knowledgeof the conservation of amphibians and reptiles, and there is a list ofprogrammes being conducted at the national and regional level.No fewer than 30 programmes are concerned with the amphibiansin this list. Among the initiatives committed to, it is interestingto note the experimental creation of pools in the Zamora regionwithin the context of a LIFE project “Cigüeña negra en Los Arribesdel Duero”4. The work also puts forward an audit of the situationfor each region and a catalogue of the important areas for Spanishherpetofauna, based on a precise methodology. In France, an action plan for reptiles and amphibians was drawnup by the Ministry for the Environment in 1996. It has not yetbeen put into practice. In the Mediterranean region, there havebeen two LIFE projects concerned in part with the conservationof temporary pools and the fauna associated with them: the“Conservation of the natural habitats and plant species of priorityinterest in Corsica” project conducted by the Office de l’Envi-ronnement de Corse between 1994 and 1997, and the “Protectionof the coastal lagoons of Languedoc-Roussillon” project conductedby the Conservatoire du Littoral et des Rivages Lacustres from1995 to 1997. Within the context of the LIFE “Temporary Pools”project, an inventory of the temporary pools of Provence andLanguedoc-Roussillon is due to start in 2004. It should enablethe most important pools for amphibian conservation to be iden-tified. Other studies have also been conducted on some species:the Crested Newt within the context of the LIFE “TemporaryPools” project, Discoglossus for which a restoration plan has beendrawn up at the request of the Ministère de l’Ecologie et du Déve-loppement Durable, and Pelobates cultripes in Provence.In Italy, a number of regional or local programmes are dedicatedto the protection of amphibians12, 335, 355 but there is no nationalcoordination as in Spain. In Portugal, the Instituto de Conservação da Natureza (ICN) hasinitiated a Red Book of the vertebrates of Portugal which will beaccompanied by an atlas of the reptiles and amphibians of Portugal.Under the impetus of the Sociedade Portuguese de Herpetologia,created in 1994, there have been numerous conservation initiativesin this country over the last ten years in favour of amphibians. In the Maghreb countries, we do not have any knowledge of anycurrent initiatives for the conservation of amphibians.

Table 8. List of amphibians which could be considered asthreatened in the French Mediterranean region

Importance of temporary pool for species: D: very important, I: important, A: accessory, NU: non used

not threatened threatened

vulnerable I: introduced

33


d. Macrocrustaceans Thiéry A.

There is a great diversity of crustaceans in temporary habitats.Microcrustaceans, with an adult size of less than 1 mm, are themain components of zooplankton, with Cladocera (Daphnia), Cope-poda and Ostracoda, which are benthic organisms. The macro-crustaceans, with a size of between 1 mm and several centimetresin the case of Notostraca (Triops and Lepidurus), are representedby the Branchiopoda other than Cladocera. Details on the mor-phology, anatomy and biology of these branchiopods can befound, among others, in Thiéry383 and Dumont & Negrea124.

The inventories and species distribution in the countries of theMediterranean Basin are well known (Tab. 9, second volume). Fiftyor so species can be counted around the Mediterranean, with amaximum of 4 to 6 species (rarely 7) coexisting at a single site382,most sites only supporting 2 or 3.

The class Branchiopoda (branchiopods) contains several orders(Tab. 10):• The order Anostraca, predominant as regards number of species,with three main families: – Branchipodidae, represented by the sole genus Branchipus, B. schaefferi being the common species in the MediterraneanBasin,– Tanymastigidae, with the genera Tanymastix, (T. stagnalis witha wide distribution, T. stellae endemic to Corsica-Sardinia, T. motasi endemic to Romania) and Tanymastigites in North Africa,– Chirocephalidae, with Chirocephalus diaphanus, very commonand abundant in the Mediterranean Basin, and the genus Linde-riella, represented by three endemic species (Provence-France,Spain, Middle Atlas-Morocco).

• The order Notostraca is only represented by a single family,Triopsidae, with the genera Triops and Lepidurus.

• Representatives of the order Spinicaudata are rarer, with some-times very localised populations, as is the case in Provence whereonly two sites are known for Cyzicus tetracerus, two sites forImnadia yeyetta and one site for Eoleptestheria ticinensis, while,for example, Chirocephalus diaphanus and Branchipus schaefferiare known on tens of sites.

Because of their origins which go back to the Devonian383, thebranchiopods are fascinating for their primitive morphologyand morphological stability to the extent that they have beenincorrectly described as “living fossils”. Their highly resilient eggs

ANOSTRACAArtemia parthenogenetica Barigozzi, 1974Artemia salina (L., 1758)Artemia tunisiana Bowen et Sterling, 1979Branchinecta ferox (H. Milne Edwards, 1840)Branchinecta orientalis G. O. Sars, 1903Branchinectella media Schmankewitsch, 1873Branchinella spinosa (H. Milne Edwards, 1840)• Branchipus blanchardi Daday, 1908• Branchipus cortesi Alonso & Jaume, 1991• Branchipus intermedius Orghidan, 1947• Branchipus serbicus Marincek & Petrov, 1991Branchipus schaefferi Fischer, 1834• Chirocephalus brevipalpis (Orghidan, 1953)• Chirocephalus carnuntanus (Brauer, 1877)Chirocephalus diaphanus Prévost, 1803• Chirocephalus ruffoi Cottarelli & Mura, 1984• Chirocephalus spinicaudatus Simon, 1886 (n)• Linderiella africana Thiéry, 1986• Linderiella massaliensis Thiéry & Champeau, 1988• Linderiella sp. Streptocephalus rubricaudatus (Klunzinger, 1867)Streptocephalus torvicornis (Waga, 1842)Streptocephalus torvicornis bucheti Daday, 1910• Tanymastix affinis Daday, 1910• Tanymastix motasi Orghidan, 1945Tanymastix stagnalis (L., 1758)• Tanymastix stellae Cottarelli & Mura, 1983• Tanymastigites mzabica (Gauthier, 1928)• Tanymastigites brteki Thiéry, 1986• Tanymastigites perrieri (Daday, 1910)• Tanymastigites cyrenaica Brtek, 1972

NOTOSTRACALepidurus apus lubbocki Brauer, 1873Lepidurus couesii Packard, 1875Lepidurus apus apus (L., 1758)Triops cancriformis mauretanicus (Ghigi, 1921)Triops cancriformis simplex (Ghigi, 1921)Triops cancriformis cancriformis (Bosc., 1801)Triops numidicus (Grube, 1865)

SPINICAUDATA• Cyzicus bucheti (Daday, 1913)• Cyzicus grubei (Simon, 1886)Cyzicus tetracerus (Krynicki, 1830)Eoleptestheria ticinensis (Balsamo-Crivelli, 1859)Imnadia yeyetta Hertzog, 1935Leptestheria dahalacencis (Rüppel, 1837)Leptestheria mayeti Simon, 1885Limnadia lenticularis (L., 1761)• Maghrebestheri maroccana Thiéry, 1988

LAEVICAUDATALynceus brachyurus Müller, 1776 (n)

NB: All the species mentioned depend on temporary pools with the exception ofthe species of the genus Artemia, which are dependent on salt marshes

• Endemic species(n) Species of northern France

Table 9. Inventory of the macrocrustacean species in the countriesof the Mediterranean Basin

Portugal Spain France Italy Malta Yugoslavia Morocco Algeria Tunisia IsraelAnostraca 3 11 12 13 2 10 11 11 6 7Notostraca 2 3 2 4 1 2 4 3 2 2Spinicaudata 2 4 4 5 1 4 4 3 2 5Laevicaudata* 0 0 1 0 0 0 0 0 0 1Total 7 18 19 22 4 16 19 17 10 15Endemic 0 3 2 5 0 4 6 2 0 0

Table 10. Number of branchiopod species in some Mediterranean countries (based on the data of Alonso8, Gauthier159, 160, Cotarelli &Mura93, Samraoui & Dumont340, Thiéry379, 380, 381, Brtek & Thiéry65, Petrov & Petrov296, etc.)

* Laevicaudata are Palaearctic species present in the northern part of some countries of the Mediterranean Basin.

34


(see Box 32 Chapter 3b) are good markers in the monitoring ofranges. The species of the genus Linderiella, for example, illus-trate continental drift. On the European, American and Africancontinents, there are five endemic vicariant* species of tempo-rary pools living in a Mediterranean climate (L. Africana, L. sp. inSpain, L. santarosae and L. occidentalis in California, and L. mas-saliensis in Provence) which all derive, by allopatric speciation*,from a parent species. Cases of endemism are possible as for thegenus Tanymastigites confined to North Africa (five specieslisted). The Balkans and mountainous regions, because of their iso-lation during the Quaternary, are also hotspots of endemism65 forseveral genera (Branchinecta, Branchipus, Tanymastix,Chirocephalus of the spinicaudatus group).

These species, which have survived various climatic crises withoutreal damage, are currently at the mercy of anthropogenic actions.The main threats are the introduction of fish (for example, frequentintroduction of Pumpkinseed Sunfish, Lepomis gibbosus, Mos-quitofish, Gambusia affinis, etc.), the destruction of sites (filling-in, digging out), and modifications to the chemical compositionof water which can inhibit hatching during submersion periods.In all cases, populations separated from each other by fragmen-tation of their distribution areas are weakened by the reductionof interchanges between them (connectivity*).

From a scientific point of view, the branchiopods are the choicesubjects for the study of metapopulations*, the understanding ofgenetic stability within populations, the diapause* phenomenaof resting eggs, ecophysiological adaptations in response to anoxia*,thermo-tolerance (secretion of protective proteins: HSPs), etc.

For all these reasons, the branchiopods are true symbols of tem-porary pools. They should be the object of conservation measuresand afforded protection status as is the case in California133 andMalta224.

e. Insects Thiéry A.

The entomological fauna of the temporary pools of the Medi-terranean Basin is now broadly known. Among the major groupsa

regularly colonising these habitats, the following can be found:• Ephemeroptera with two genera, Cloeon and Caenis,• numerous Odonata (dragonflies), with Zygoptera (Lestes, Isch-nura, Coenagrion) and Anisoptera (Sympetrum, Aeschna, Anax,Crocothemis, etc.),• numerous Heteroptera (water bugs): Notonecta, Plea, Sigara,Corixa, Micronecta and Gerris,• Coleoptera: Dytiscidae (Dytiscus, Agabus, Noterus, Coelambus),Gyrinidae (Gyrinus), Helophoridae (Helophorus, Berosus, Hydrous,Anacaena), Haliplidae (Haliplus), etc.,• some Trichoptera (Limnephilus, etc.),• Diptera, mainly represented by the Chironomidae, Ceratopo-gonidae and Culicidae.

Ephemeroptera, Odonata, Trichoptera and Diptera are only pre-sent in water in the larval form; Heteroptera and Coleoptera, onthe other hand, also the use the habitat in the adult state (ima-gos). In all cases, the biological cycles of the insects include anaerial phase and an aquatic phase, unlike those of the crusta-ceans of permanent aquatic habitats (Cladocera, Copepoda, etc.),all the life stages of which occur in aquatic habitats. From the biogeographical point of view, the majority of insectsinhabiting the temporary habitats of the Mediterranean regionare of Palaearctic origin, including those of North Africa. Endemicspecies are very rare, and most species have fairly extensive ranges.The composition of the insect communities of temporary pools isvery variable and to a large extent determined by the hydrologyof the habitat. The number of species of insects increases withthe duration of submersion (Tab. 11):• If the habitat is ephemeral, only some generalist* Diptera arefound, with short life cycles, such as the chironomids and someculicids (mosquitoes). These species interact only very little with thecrustacean fauna which is dependent on this habitat (Chapter 2d):the system functions with isolated entities, with no trophic* inter-actions.• When the submersion period is longer, colonisation by someinsects can be seen (Ephemera: Cloeon, hydrophilid Coleoptera:Berosus, Helophorus, dytiscid Coleoptera: Coelambus, Agabus);usually herbivores or detritivores. These insects may lay eggs inthe pool allowing the invertebrate community to become morecomplex.• When water remains in the pool for several months, a secondwave of colonising insects, often predators, arrives: the Odonata,Heteroptera (Notonecta, Plea, Corixa, Sigara) Coleoptera (Gyrinus,Gerris, Dytiscus). In these pools with a long submersion period,the species richness increases and trophic chains diversify.A massive arrival of insects is explained by migratory flights,described, for Coleoptera, by Fernando139, Fernando & Galbraith140,

a. For the taxonomic identification of insects see Tachet et al.368 which covers all theMediterranean Basin. For Odonata see D’Aguilar & Dommanget101 and for ColeopteraFranciscolo150 and Pirisinu301.Triops cancriformis, a flagship crustacean of temporary pools

Roch

é J.

35


Landin220, Landin & Vepsäläinen221. Numerous factors influencethe migratory movements of insects:• Meteorological factors (sunshine, clouds, temperature and airhumidity, winds). Colonisation experiments in artificial basins, con-ducted by day and by night, have shown that large Coleoptera(Agabus, Acilius, etc.) migrate on nights when there is a full moon,that the chironomid Diptera migrate regularly in overcast weather,while Notonecta (Heteroptera) prefer to migrate in sunny weather(Thiéry, original data). Incident light plays an important role inthe recognition of water bodies and thus in the colonisation oftemporary habitats (triggering a descent reflex after visual stim-ulation). Generally speaking, wind speed constrains migration.• These meteorological factors can be associated with biotic fac-tors such as the growing density of populations when the dryingout comes to an end. This density increases the frequency of con-tact between individuals and triggers migration flights in Sigarafor example.• Migration also depends on ecophysiological factors withinpopulations. Some species have an anatomical polymorphism, ofgenetic origin, which determines the development of the muscu-lature of the wings and thus their aptitude for flight. In corixidHeteroptera Corixidae415 and Gerridae, for example, cases of atro-phied musculature or wing reduction are frequent in permanenthabitats. In temporary pools, on the other hand, forms with com-plete wing musculature have a certain selective advantage forcolonisation and migration according to whether the habitat con-ditions are favourable or unfavourable.During periods favourable to migratory flight (appropriate airtemperature), the colour of the water appears to influence thecolonising species. This colour corresponds to the amount of dis-solved and suspended mineral and organic material, and thus tothe time elapsed since the flooding of the pool380.

The richness and diversity of entomological fauna also dependson the development of macrophytes, the dissolving of organicmaterial, the development of microbial populations, etc.Though most insects colonise varied habitats, some are depen-dent on a habitat, a type of vegetation or a plant species. TheColeoptera of the genus Haliplus feed on the calcified branchesof Characeae. Some Odonata are also dependent on macrophytes,plants with floating leaves347 or plants immersed in stagnantwater255. In Provence, the terrestrial coleopteran Agrilus lacus isstrictly dependent on Artemisia molinieri, and is thus endemic, asthat is, to three temporary pools.Some particular adaptations enable certain insects to survive intemporary pools. Some species can burrow and subsist, in a stateof reduced activity, in sediments in adult or larval form. TheColeoptera Helophorus and Berosus reach a depth of 3 to 6 cmin sediments with a water content of around 40 to 50%. In thecase of larval burrowing, larvae can pupate in a dry location, forexample Berosus guttalis376, or survive for several weeks until the

pool is submerged again, for example the anisopteran Sympetrumstriolatum190, and the chironomid Polypedilum pharao375.

Insects are an important part of aquatic biocenoses. Whether inMorocco380 or Provence372, 386, they constitute from 60 to 70% ofthe total number of species present over a complete hydrologicalcycle (for example, 118 insects out of 143 invertebrates in south-east France or 60 to 76% for pools in the arid zone of Jbilets,near Marrakech, Morocco).The Odonata of temporary habitats may only be transient (theaeshnid Anisoptera which can cross the Mediterranean) or may bedependent on temporary pools (around 20 species). These latterare adapted through their short biological cycles, with rapid lar-val development. Certain species also have an optional embryonicdiapause341 which enables them to adapt to the unpredictabilityof the habitat. These are some Lestes (L. viridis, L. barbarus),Libellulidae such as Tanetrum fonscolombei (syn. Sympetrumfonscolombei), some Sympetrum (S. sanguineum and S. striola-tum found at Lanau, in the poljés of the Var, etc.) or Crocothemiserythraea. Generally speaking, diversity of vegetation is one ofthe factors determining the number of species of Odonata of apool120. Though the Zygoptera, because of their jerky flight, donot cover large distances, the Anisoptera, in contrast, have morehomogenous distributions and cover larger areas229.In addition to the aquatic insects sensu stricto, a large number ofinsects living on the surface of the water, in vegetated fringingzones, etc. increases the species diversity of these habitats. Theimportance of these insects in the functioning of these habitatsis described in Chapter 3e.

Table 11. Diversity of Odonata (Zygoptera and Anisoptera), Heteroptera and Coleoptera in relation to the duration of submersion of thepool (based on Thiéry375, 380; Terzian372)

Ephemeral pool Provence(Esterel, France)

Temporary pool JbiletsMarrakech (Morocco)

Lanau pool (Crau, France)

Bonne Cougnelong submersion pool (Provence, France)

Duration of submersion (in months) 1 4 6 8Number of species of Odonata 0 2 8 14Number of species of Heteroptera 2 9 18 17Number of species of Coleoptera 3 22 47 13

Ischnura pumilio: its biology and ecology enable it to colonise temporar-ily flooded habitats with ease

Papa

zian

M.

36

3. Ecosystem and populationfunctioning and dynamics

a. Introduction Gauthier P. & P. Grillas

The essential ecological characteristic of temporary wetlands isthe alternation of flooded and dry phases. During each of thesephases, various environmental factors play an important role inthe structure and dynamics of these ecosystems. During theflooded, aquatic phase there is poor availability of dissolved oxy-gen and carbon dioxide for the plants which, to compensate forthese disadvantages, have developed anatomical and physio-logical adaptations (serrated leaves, reduction of cuticle thick-ness, use of carbonates instead of CO2 for photosynthesis, etc.).During the dry phase (summer), the dryness of the soil is a veryimportant limiting factor for the survival of organisms. It is linkedto the thickness and nature of the sediment (useable waterreserves for plants, damp refuges and crevices for the animals toretreat into). Several ecosystems could indeed be said to occupythe same place in turn via a succession of phases: the first sub-merged, with floating plants and swimming animals, followed bya progressive drying-out phase with amphibious plants, then adry phase with terrestrial vegetation and fauna.

A second important ecological characteristic of temporary poolsin a Mediterranean climate is the great interannual variation inrainfall (frequency and intensity) resulting in unstable submersionconditions (see Chapter 3b).

This succession of contrasting phases which varies from year toyear favours the emergence of varied and specialised plant andanimal communities which are particularly adapted to the insta-bility of the habitat157. In plants, annual species are favoured aswell as perennial species with anatomical structures enablingthem to withstand the dry phase260: bulbs of geophytes* (Isoetessetacea, etc.) and the fleshy roots of hemicryptophytes* (Menthapulegium, etc.).

Other environmental factors such as the level of calcium andnutrients* (nitrogen, phosphorous) are fundamental to the func-tioning of these temporary habitats. Many plants do not toleratethe presence of calcium, the concentration of which determinesthe establishment of major vegetation types. For example, habi-tats poor in limestone and more generally in dissolved elementsare favourable to formations of Isoetes. Formations of Heleochloion(Heliotropium supinum, Crypsis schoenoides, etc.), on the other hand,are often encountered on limestone-rich substrates. Similarly,crustaceans need calcium to build their carapace.

Eutrophication of natural (the accumulation of plant debris) oranthropogenic (input of fertiliser) origin can upset the balanceof communities and lead to their banalisation, i.e. the replace-ment of the characteristic species by more productive, non-specialised species (reeds, Scirpus, etc.). The eutrophication ofwater, combined with the phenomena of filling-in by fine or largesoil particles (aggradation*), also favours habitat closure by woodyspecies. This process leads not only to an increase in competition forlight among plants but can also modify the duration of flooding

(via evapotranspiration) and the temperature of the pools, whichaffects the flora and fauna. Other phenomena such as sedimentation or, inversely, erosionmodify the hydrological regime of pools and temporary streams.

Another essential factor for the plant and animal populationsdependent on temporary pools is their discontinuity. Their disper-sal at the scale of the Mediterranean Basin and their scattereddistribution within the same region create very isolated habitats.The species occupying these habitats thus appear in the land-scape in the form of fragmented populations within a matrix ofnatural (dry grasslands, maquis or forests) or anthropogenic(fields, vineyards, etc.) habitats.

The subjugation of species to environmental constraints varies inrelation to their life strategies and their mobility. Certain speciescomplete their entire life cycle in these habitats (plants and crus-taceans, for example). Others must of necessity complete a phaseof their life there (amphibians, for example). More opportunisticspecies are not dependent on temporary habitats but profit fromtemporarily favourable conditions to complete a part of theircycle there (dragonflies for example).

Converging life strategies have sometimes evolved in plants oranimal species of temporary habitats, including a great adapt-ability in the life cycle in response to modifications in the habi-tat18. Thus, for example, when water levels are reduced in thespring and the water temperature increases, development isaccelerated in some invertebrates or amphibians (advanced meta-morphosis) and plants (the early flowering characteristic of speciesknown as ephemerophytes*). Annual plants and crustaceanshave recourse to drought-resistant reproductive organs, seeds oroospores* for the former and eggs or cysts for the latter. Theseorgans constitute “banks” in the sediment enabling them to respondto unpredictable factors in the habitat by ensuring a stock thatgerminates or hatches, not simultaneously but over a number ofyears. In amphibians, the adult lifespan means that they need notattempt to breed in years when hydrological conditions areunfavourable.

37

3. Ecosystem and population functioning and dynamics

b. Hydro-climatic characteristics Chauvelon P. & P. Heurteaux

In temporary pools, as in all wetland biotopes, water is the mostessential, most formative element for the functioning of ecosys-tems. Temporary pools are characterised by fluctuations in waterlevels (Fig. 5) which determine ecological factors such as theduration of flooding, the dates of flooding and drying out, anddepth.

The volume of water in a pool varies, partly in relation to theinflow of rainwater (direct or indirect) and underground water,and partly in relation to losses by evaporation, overflow or infil-tration. The rains falling in the catchment area follow three routes:they evaporate, flow over the surface or infiltrate the soil. Theproportion which follows each of these routes depends on thenature of the substrate, the topography and the plant cover.Losses into the atmosphere (in the form of water vapour) are dueeither to vaporisation from wet substrates (open water, soil andcanopy dampened by the rain) or plant transpiration. Together,these two phenomena are known as evapotranspiration. Its impor-tance is in relation to the density and nature of the plant coverof the catchment area. Run-off and infiltration depend on thepermeability of the substrate and the slope. For example, run-offis greater on sloping compact rock, whereas infiltration is greateron a porous rock with shallow slopes. In the natural state, the seasonal and interannual variations in thevolume of water stocked in a pool result from temporal varia-tions in the ratio/balance of inflows (direct rains, surface run-off,inflow of underground water) and outflows (infiltration, overflowand evapotranspiration). This natural state can be perturbed byhumans (irrigation, drainage, domestic uses, for example).

Depending on the geological and geomorphological context, agreat diversity of hydrological regimes is encountered (Fig. 6). Toidentify to what major type of hydrological regime a given pool

The two extreme ecophases (flooded and dry) of a temporary Mediterraneanpool (Plaine des Maures, Var, France)

Figure 5. Variation in water levels in the temporary marshes of Cerisières Sud (Camargue) and in a marsh in the Marrakech region (basedon Grillas & Roché175, added to)

Stock = [rainfall (direct + run-off)] – [evaporation of the open water + transpiration] ± underground water ± anthropogenic actions

Cata

rd A

.

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er le

vel (

cm)

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1991-1992 1992-1993 1993-1994 1994-1995 1980-1981 1981-1982 1982-1983 1983-1984 1984-1985

S N J M M J

1995-1996

S N J M M J S N J M M J S N J M M J S N J M M J S N J M M J

La Cerisière sud marsh Camargue, France

Wetland near Marrakech Morocco

Surface run-off dominant

Hydrological basin catchment different from the surface water catchment area

Surface reservoirs in a karst system

Overflow of rivulets on an impermeable rock

Small cupules on impermeable rock

Boundary of the surface water catchment

Run-off

Water input from groundwater

Water loss towards groundwater

Permeable substrate

Impermeable bedrock

Marl

Limestone

Impermeable rock

rivulet

38


conforms to, the different hydroclimatic processes involved in thisregime must be characterised and quantified. It is a difficult under-taking, each case being unique not only because of the physicalparameters characterising the pool and its environment but alsobecause of the practical problems and budgetary constraintswith which the manager is confronted. Hydrometric equipment isexpensive and the cost of hydrological and hydrogeological studiesis always relatively high, thus too often difficult to finance.

The nature of the data to collect is very varied:

The geographical context

A reliable and updateable description of the physical and geo-graphical characteristics of the system being studied must be made.The following is a non-exhaustive list: topography, geology, pedo-logy and land use. Often, in the particular context of wetland areas,knowledge of certain characteristics of the socio-economic sys-tem can prove to be essential: agricultural practices in relationto water management, inventory and methods of managing thehydraulic infrastructures.

Figure 6. Typology and hydrological functioning of temporary pools

39


Hydroclimatic regime

As the basic issue in hydrology in the broadest sense, i.e. includinghydrogeology, consists in knowing the distribution and quantifyingthe terms of the hydrological balance, as much climatological dataas possible, which must be as accurate as possible, needs to begathered. It is essential to know:• the temporal distribution of rainfall because of its incidenceon the submersion of the aquatic habitat studied and significantconsequences for its biological communities,• the climatic factors determining the evaporating power of theatmosphere such as the saturation deficit, the air temperature,solar energy radiated (or the duration of insolation) and the windspeed. Evaporation of open water and plant transpiration increasewith the evaporating power of the atmosphere. The evaporationof open water is even higher if the thermal inertia of the waterbody is low (pools in drying-out phase). In addition, plant transpi-ration depends on the degree of humidity of the substrate and onthe species and its stage of development.

Underground water

Underground water occupies the gaps in porous rocks. It includesthe capillary water of the aeration zone of the ground which isthe reservoir drawn upon by vegetation and, deeper down, thegroundwater. The interface between the saturated zone andthe unsaturated zone forms the piezometric surface. In a permeableor semi-permeable habitat, the surface water and undergroundwater are interconnected and are involved in interchanges.Depending on the magnitude of inputs due to infiltrations ofrainwater and of losses by evapotranspiration from the ground,the position of the piezometric surface varies in relation to thebottom of the pool. The pool will tend to supply the groundwaterif the piezometric surface is situated under the bottom of the pool.If it is situated above the level of the open water, the ground-water will tend to supply the pool until the levels are balanced.For intermediate levels between the bottom and the water of thepool, the pool will supply the groundwater to a greater or lesserextent depending on the permeability of the land.Underground water cannot be seen. To study its dynamics, pro-cedures and measuring equipment need to be put in place whichare often sophisticated and expensive and only available to spe-cialists. Fortunately, satisfactory management of a temporary

pool does not require intimate knowledge of the relationshipbetween underground water and surface water. Usually all thatis needed for a “health check-up” of these to be made, is to regu-larly follow the progression of easily measurable parameters (watercycle, physicochemistry). Knowing the influence of underground water is nonetheless essen-tial in some cases, notably in relation to the physical planning ofa water body, or to assess the consequences of human activitieson the catchment area. In this case, it is advisable to call uponthe services of a research consultancy or specialist university labo-ratory.

An initial approach can be made using relatively simple methodsand will enable the necessity of starting further research to beassessed. A network of piezometers (see Chapter 6b) will provideinformation on the dynamics of underground water. However,their installation can prove to be difficult because of the natureof the terrain and the risks of vandalism. In certain cases, simplythe variations in the level and/or the electrical conductivity ofthe surface water will clearly reveal the involvement of under-ground water in the water cycle of a pool (Box 12).

Important factors for the biology

For a full understanding of the biological phenomena in pools, agreat number of variables are likely to be important. They shouldbe prioritised according to local situations. • When the topography is known, the volume of water is assessedby the regular measurement of the level and thus gives informa-tion about the dates of flooding and of drying out (duration ofsubmersion) which are the most important factors for the livingorganisms. • The hydric state of the sediments which have gradually emergedis a factor upon which the survival and development of indi-viduals (fauna and flora) after drying out depends. • The chemical composition of the water is always an importantfactor for fauna and flora. In addition to the usual physico-chemical characteristics (temperature, pH, dissolved oxygen,electrical conductivity), the ionic composition of the water canaffect the presence or abundance of certain species. In this respect,the lithology of the catchment area and the bottom of the pool(granite, schist, limestone, etc.) is a good indicator which can beconfirmed by an analysis of the ionic balance by a specialistlaboratory.

Box 12. An example of involvement of underground waterin the seasonal cycle of a temporary water body: The Etangde Valliguières (Gard)

The problems of water supply to the pool were dealt with in 4successive phases: Preliminary study of existing documents: topographical and geo-logical maps, aerial photos, reports of hydrogeological surveyThe depression of Valliguières is located in the centre of a broadkarstified limestone plateau (Cretaceous period). It is bordered byhigh, fairly steeply sloping rock faces, faulted at their base. The presence of water in the depression is attested to by theexistence of a large spring (which provides water for the village),of seepages marked on the IGN topographical map, and by thebrook of Valliguières. The Etang de Valliguières occupies a lowarea of around 2 ha at the foot of the rock face to the east of thedepression.

Preliminary field observations, late April 2000The Etang de Valliguières is an endorheic* temporary water bodywhich neither receives from nor supplies a stream. The limestonebottom of the water body is covered with a layer of fairly pebblyimpermeable marl of variable thickness. Two old watering places,dug out by humans, are the last holes to hold water before thesummer drought when it occurs. One (called below “Pool of thenewts”) is built up against the rock face, the other (known as the“Large pool”) is further away.Information from the local inhabitants indicates that the waterregime of the Etang de Valliguières tallies with that of the rains.It remains flooded in very wet years and dries out earlier or laterin the spring in dry years. However, field observations, added tothe features shown on the maps (spring, etc.), has led to anotherhypothesis of being put forward other than simply the opposingeffects of rain and evaporation.In late April 2000, there was around 25 cm of water in the “Poolof the newts” whereas the “Large pool” had already dried out.

As the bottom of the two pools was impermeable, the activity ofrain and evaporation alone was not enough to explain the diffe-rence in behaviour of the two pools during the spring. Furthermore,a hand auger bored into the marl at the bottom of the “Large pool”remained empty of water whilst another auger on the edge of the“Pool of the newts” filled with water up to the level of the pool.

A working hypothesis The seasonal hydrodynamics of the Etang de Valliguières is notdirectly governed by the action of rain and evaporation on thelevel of the water body itself, but indirectly by means of theunderground water of the limestone plateau which overhangs it.The water body is supplied by seeping from the karstic aquiferwhich penetrates the marl stratum by force through fissures atthe foot of the rock face.

Surveys on the ground (2000-2002) confirmed this hypothesis.• Monitoring of water levels (Fig. 7)Comparison of the actual change in water level with what wouldhave resulted just from the balance of rainfall contributions andlosses by evaporation showed a very clear discrepancy betweenthe two. The levels calculated were generally higher than thosemeasured in the period when there was a drop in the water levelof the water body and lower in the period of flooding. The waterlevel range* can exceed 5 m.• Monitoring of the electrical conductivity of the waterGenerally speaking, the conductivity of the water is higher in aperiod of flood (as a result of the input of the more mineralisedwater of the karstic aquifer) than in the period when there is adrop in level (no karstic input). The conductivity in the high waterperiod is comparable to that of the spring supplying the village(0.7 – 0.8 mS.cm-1 at 20°C).• The pool-karst complex functions according to the principle ofcommunicating basins (Fig. 8).

Heurteaux P. & P. Chauvelon

40


Figure 8. Interpretation of the seasonal dynamics of subterranean waters and water bodies (based on Heurteaux186)

■ Barremian Limestone■ MarlD drilling

■ Water of karstic origin■ Water arising from saturated marl■ Pond floodwater

Situation end of April 2000

Karst Pond Karst Pond Karst Pond

Situation end of July 2000

h D

Mar

e au

x tr

itons

Gra

nde

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e

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e au

x tr

itons

dry

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h

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Situation March 2003

Loss of hydraulic pressure caused by friction forces which counteractthe rise of water in the layer of marl at the bottom of the pool


Box 13. An example of complex functioning: the BonneCougne pool (Var)

The temporary Bonne Cougne pool has a water supply whichgives it a distinctive hydrological regime. This results in bothfloristic1, 361 and faunistic204, 386 richness.A bimonthly analysis of the physicochemical quality of the waterthroughout a hydrological cycle has enabled the origin of thewater and its changes over time to be determined130.

Four phases can be distinguished (Fig. 9):Phase 1: after the drying-out period corresponding to the drysummer season, the biotope is flooded by surface run-off water.Water chemestry is characterised by a low degree of mineralisa-tion (C20 <250 µS.cm-1) and a calcium bicarbonate facies.

Phase 2: around 2 months later, the karstic aquifer begins to flowand contributes to the pool’s supply; its water is clearly moremineralised (C20 600 to 750 µS.cm-1) with a raised sulphate level.The beginning of the mixing of the waters can be seen.

Phase 3: less water overflows. The mixing of the two types ofwater becomes more marked.

Phase 4: the supply is reduced and dries up, and the pool closes(water no longer overflows). Lowering of the water level occursonly by evaporation, the lake bottom being totally impermeable.Mineralisation of the water increases naturally by evaporation.However, a distinctive feature is noted with regard to certainions, such as the strong reduction in calcium and sulphate levels,the result of intense biological activity linked to the growth ofCharaceae (the precipitation of calcium carbonates wasdescribed by Levy & Strauss233). In the Bonne Cougne pool, thepopulations of Chara vulgaris, C. contraria and C. connivens formdense beds, with a biomass able to reach 300 to 550 g of drymatter per m2. Note that in addition to Characeae, Ostracoda(mainly Cypris bispinosa and Eucypris virens), crustaceans withcalcified valves, contribute to the removal of calcium from thewater.

The conjunction of successive abiotic factors (surface run-offcollecting the water from the topographic basin, then input fromthe underground water of the karst) and biological control(growth in the Characeae precipitating the carbonates) give thisMediterranean temporary ecosystem a unique regime.

Emblanch C. & A. Thiéry

Flooding: December 2001

OverflowRun-off

Run-off

Karst water

Karst water

Run-off

Overflow

Overflow

January-February 2002

March-April 2002

May 2002 at the drying out

Phase 1

Phase 2

Phase 3

Phase 4

Figure 9. Diagram of the mixing of the waters at Bonne-Cougne

Figure 7. Monitoring of water levels at the Valliguières pool

41

3

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42


c. Vegetation Gauthier P., P. Grillas, V. Hugonnot & J.P. Hébrard

The hydrological regime of the pools, with a range of variablessuch as water level, duration of flooding, dates of filling with waterand of drying out, is the essential factor determining the distri-bution and characteristics of the vegetation. Other factors arediscussed using a typological approach (characteristics of thesubstrate, Chapter 2a) and in the chapter dealing with the effectsof human activities (nutrients, pollution, grazing: Chapter 4).

Water levels and vegetation structure

In a given pool the spatial and temporal distribution of the veg-etation is primarily determined by the water-depth gradients andthe duration of flooding. Over a hydrological cycle the vegetationof temporary pools will be successively dominated by differenttypes of plants: aquatic species during the flooded phase, fol-lowed by amphibious plants as the pool is drying out and finallyterrestrial plants during the dry phase (Box 14). This successionis subject to variations between years: in very wet years aquaticplants will develop more, to the detriment of terrestrial or oppor-tunist species. Similarly, the spatial distribution of the vegeta-tion, in the form of belts, is also determined to a large extent byhydrological gradients.

Zonation

The topographical gradients in the pools correspond to gradientsin the duration and depth of flooding242. The vegetation in thepools is organised principally along these gradients (Box 14).

Box 14. Vegetation zonation in a Moroccan pool In Moroccan pools three zones (three belts) are often recognised(Fig. 10): • A central zone, where communities of aquatic annuals(Nitella translucens, Callitriche brutia, etc.) are replaced, inspring, by communities of amphibious annuals or perennials(Illecebrum verticillatum, Isoetes velata, etc.), and then in sum-mer by communities of hygrophilous* terrestrial annuals(Heliotropium supinum, Pulicaria arabica, etc.).• An intermediate zone, where perennial species (Scirpus mar-itimus, Eleocharis palustris, etc.) form a mosaic with annuals(Lotus hispidus, Lythrum borysthenicum, etc.).• An outer zone which dries out more quickly, supportingmesohygrophilous* vegetation. It includes characteristic annualamphibious species (Juncus capitatus, J. pygmaeus, Pilulariaminuta, Elatine brochonii, etc.), or geophytes* (Isoetes histrix,etc.), more generalist* species (Polypogon monspeliensis, etc.)and sometimes terrestrial woody plants (Cistus spp, Cynarahumilis, Asphodelus microcarpus, etc.).

Rhazi L. based on Rhazi et al.326 ; Rhazi et al.327

Figure 10. Zonation of the vegetation in the Benslimane pool

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◆ ◆

◆◆ ◆ ✚

◆ ◆ ◆ ◆ ◆ ◆◆ ◆ ◆ ◆ ◆ ◆ ◆

▼

▼ Plantago coronopus ● Hypericum tomemtosum◆ Pulicaria arabica

● Isoetes velata◆ Lythrum biflorum ✚ Scirpus maritimus

▼ Glyceria fluitans● Myriophyllum alterniflorum◆ Callitriche brutia

Outer belt

Intermediate belt

Central belt

Intermediate belt

Outer belt

43


Each zone is colonised predominantly by species showing specificecological characteristics: those in the central zone must be ableto tolerate a long period of immersion, and those in the outerzone must withstand severe drying out. In the intermediate zone,the stresses caused by flooding and drought are not very intensebut interspecific competition is often more intense. The belds ofvegetation corresponding to the zones are generally characterisedby decreasing species richness from the outer belt towards thecentre of the pool (Fig. 11).

This zonation is more or less marked at different sites, dependingon the topographical gradients. It rarely conforms to a rigid patternand varies in relation not only to the topographic and hydro-logical characteristics of the site but also to unpredictable per-turbations (Fig. 12). In addition, the zonation is locally modifiedby the colonial nature of certain species (mats of perennial rushesfor example).

The limits of the zones and their species composition vary betweenyears. They may be displaced towards the centre or the edge ofthe pool depending on whether the year is very dry or very wet.The relative abundance of perennials and annuals in the beltsalso varies in accordance with flooding levels: a succession of dry

Figure 11. Species richness of the vegetation and seed stocks inthe three vegetation belts of a daya in Morocco

Central Intermediate Outer

40

35

30

25

20

15

10

5

0

■ Seeds stocks■ Vegetation

Num

ber

of s

peci

es

Vegetation

Meso-hygrophilous grassland(terrestrial grasses dominant)

Wet grassland

Hygrophytic community with perennial rushes (Juncus conglomeratus)Amphibious community with Ranunculus rodiei

Aquatic community with Callitriche(Callitriche brutia)Shrubby vegetation

Perennial grassland

Map

: A. C

atar

d (C

EEP)

, M. P

icha

ud, A

San

doz

&N

. Yav

erco

vski

(Sta

tion

biol

ogiq

ue d

e la

Tou

r du

Val

at)

0 1.5 3 m

Figure 12. Zonation of the vegetation in the Rodié pool (Var, France)

44


years will see a steady increase in terrestrial species and peren-nials, especially in the outer belt of vegetation (Box 15). Theinterannual variations in the vegetation depend to a large extenton the seedbank. These temporal variations can be revealed bycomparing the surface vegetation with the seedbank323.

The difference in the relative abundance of species between theseedbank and the vegetation may be caused by a number of fac-tors including the biological characteristics of the species (lifehistory traits*), the processes involved in the accumulation of theseedbank (see below), and the ecological functioning of the pools.Investment in seed production is greater among species with abrief life cycle (annuals) than among those with a long cycle. Thesize and vigour of the seedlings are directly dependent on thesize of the seeds. Depending on the species, the resources allo-cated to reproduction will be invested either in few, large seedsor in small but very abundant seeds. Thus in the temporary marshesof the Coto Doñana there is a negative exponential relationshipbetween the density of seeds and their individual weight174. Environmental conditions, such as hydrology or competition, maysuppress the germination of seeds for variable lengths of time.

Survival strategies associated with hydrological fluctuations

The variability of the environmental conditions favour annualspecies with short cycles, adapted to one or the other phase of thehabitat (dry or wet), or to the transition period (amphibious species).Annuals account for about 80% of the characteristic species oftemporary wetlands260 (Box 16). Annuals invest a large propor-tion of their resources in the production of seeds and spores(sexual reproduction), allowing them to withstand the unfavou-rable period. In addition, they show a certain degree of flexibilityin the completion of their biological cycle. Their flowering maybe advanced or delayed depending on whether rainfall comes earlyor late25.Despite the dominance of annuals, perennials can also live intemporary pools if they are able to find their preferred habitat.Among these, Isoetes species (second volume) possess adaptationswhich give them great flexibility in responding to the irregularityof the alternating dry and wet phases. These are of a physio-logical nature, such as the ability to carry out photosynthesis inboth dry and wet conditions, or the high degree of tolerance oftheir corms to desiccation. The life cycle may also be shortenedas, for example, in Isoetes velata, which, in the extreme condi-tions of the cupular pools of the Colle du Rouet (Var, France),undergoes an annual cycle303. These populations are only viablebecause the species is able to produce spores from its first yearof life; such species are known as facultative annuals.

Perennial plants that are less specialised and more tolerant ofboth aquatic and terrestrial phases are also found in the pools.They may correspond to amphibious species in conditions of pro-tracted flooding (Scirpus maritimus, Eleocharis palustris) when

Box 15. Interannual changes in the species composition ofthe outer zone of the Benslimane poolThe species composition of the vegetation was monitored in aMoroccan daya over 7 years (1997-2003). The vegetationchanged with rainfall amounts, more rapidly in the outer beltthan in the centre of the pool. Between two exceptionally wetyears (1997 and 2003) terrestrial perennials (mainly scrub:Cistus salviifolius and C. monspeliensis) recolonised the outervegetation beld (Fig. 13). They amounted to 27% of the florain 1997 following exceptional flooding, 73% in 2000 and 2002during the dry years and fell again to 28% in 2003 afteranother very wet winter.

Rhazi L. based on Rhazi et al.326 and unpublished data

Figure 13. Percentage of cover of perennials in the outer zone ofthe Benslimane pool between 1997 and 2003 in relation to cumu-lated rainfall (number on the bars)

Box 16. The hydrological regime and the composition ofthe vegetation The date of flooding results from a combination of several vari-ables such as temperature, insolation and day length. In fieldexperiments Grillas & Battedou172 showed that the date offlooding is a decisive factor for the development of communitiesof aquatic annuals and that it determines their species composi-tion (Fig. 14). Early flooding (in September) leads to the establish-ment of species-rich communities. Conversely, late flooding (inMarch) results in a reduction in the number of species andin dominance by opportunist species (Zannichellia spp.). In testing the effects of three flooding dates (February, Marchand April) on Californian vernal pools, Bliss & Zedler37 recordeda decrease of 52% in species richness for late flooding, in April,compared with early flooding, in February. With early floodingthe vegetation is rich in the characteristic species of tempo-rary pools. In contrast, during late flooding the vegetationbecomes more commonplace through an increase in more gene-ralist species (Lythrum hyssopifolium, Crassula aquatica, etc.).These authors considered that the suite of characteristic tem-porary-pool species would be protected from “out-of-season”germination by an inhibitory mechanism linked to temperatureincreases.

Gauthier P. & P. Grillas

1997 1998 1999 2000 2001 2002 2003

Cove

r of

per

enni

als

(%)

80

70

60

50

40

30

20

10

0

689 371

323

300 262296

668

45


Box 17. Key factors for the development of Charophytes*In temporary pools, the Characeae are regulated by the dynamicsof the flooding/drying phases. Their vegetative structures cannottolerate any drying out and in dry conditions they can only sur-vive in the form of perennating organs (oospores* and gyrogo-nites*). Their biological cycle, from germination to the productionof perennating organs, generally lasts from five to seven months.A period of three months under water is the absolute minimumrequired for their development, even among early species. Theoospores do not break dormancy* until 21-28 days after flooding400,and if the period of submersion is too short, the plants will not beable to develop to the sexual reproductive stage. The duration ofdevelopment is crucial and excludes these plants from ephemeralhabitats which are only flooded for a few weeks.

The date of flooding, and its correlate, temperature, have a stronginfluence on the type of species which are able to germinate. Onlyautumn or early winter flooding allows the development of thevernal species which are of the highest value in terms of naturalheritage, such as for example Nitella opaca, Tolypella spp.,Sphaerochara and Chara imperfecta. These species are all themore valuable as life forms in the pools since they appear at atime of year when aquatic phanerogams are still completelyabsent. These taxa develop at low temperatures (less than 10°C)and yellow and decompose above 18.5°C (361). Their rarity is proba-bly due to the fact that good conditions do not occur every year.At the LIFE sites in the Var Département, the 2000/01 cycle wasoptimal for these plants, whereas they did not reappear duringthe two following winters. Delayed flooding resulted in strongcompetition with higher plants and gave rise to an increase inopportunistic species such as Chara vulgaris and C. globularis.This impoverished and generalist* flora occurs in 80% of surveyedpools in Languedoc-Roussillon (Soulié-Märsche, pers. obs.).

Light penetration and temperature are the key factors essentialfor the production of seeds and the formation of oospores and gyro-gonites, which are especially necessary in a temporary environ-ment. Temporary-pool species invest heavily in the formation of

gyrogonites which can then withstand drought conditions lastingfor several consecutive years.

The surface area and topography of a site influence the diversityof Characeae. Particularly light-demanding species will in generalonly grow at depths of under 2 m. An environment where depthincreases progressively (0-2 or even 4 m) will give rise to a gra-dient of Characeae species according to depth, as well as to aseasonal succession as the depth decreases due to evaporation.The Bonne Cougne pool (Var) has an exceptional degree of biodi-versity thanks to its wide range of constituent microhabitats130.Ten species of Charophytes, of which five are extremely rare,appeared in turn here during the 2000/01 cycle361.

The Protection of Characeae, and especially rare species, at tem-porary pools requires above all the continuation of alternatingperiods of flooding and drying out. A temporary pool transformedinto a permanent habitat will undergo rapid changes in its rangeof species and will be occupied by commonplace species, such asChara vulgaris which is by far the most widespread in Europe.Many Characeae are also capable of vegetative reproduction* bynodal bulbils, and adopt a strategy of spreading when they occurin a permanent habitat, which results in monospecific stands oflesser interest for biodiversity.

A second threat factor, not only for rare species but also forCharaceae in general, is pollution in the broad sense and over-enrichment with nutrients*. The Characeae can only tolerate lowlevels of sulphates, nitrates and phosphates in the water. In poolssurrounded by arable land in Languedoc-Roussillon, the leachingof fertilisers and herbicides must be regarded as the reason forthe disappearance of many populations over the course of recentdecades.

Soulié-Märsche I.

Figure 14. Species composition of the vegetation in relation to the date of flooding (based on Grillas171)

■ Zannichellia pedunculata

■ Zannichellia obtusifolia

■ Callitriche sp.

■ Chara aspera

■ Chara sp.

■ Ranunculus sp.■ Tolypella sp.

September 24 November 26 March 11

46


incomplete drying out permits the survival of rhizomes and corms.Opportunist terrestrial perennial species also temporarily colonisetemporary pools during dry years, in the dried-out zones. Theseinclude for example grasses such as Dactylis hispanica, Holcuslanatus or Agropyrum campestre in Les Maures. Woody plantspresent in the adjoining ecosystems are also found here, such asCistus. These species undergo drastic fluctuations in abundance:they thrive during a series of dry years and are wiped out whenflooding takes place. Finally, some terrestrial species are well ableto tolerate winter flooding and are frequently found in temporarypools although they are not specific to this habitat (for exampleDittrichia viscosa and Cynodon dactylon).

The seedbank

As well as the organs of vegetative propagation of perennialplants (bulbs, bulbils, rhizomes, turions, dormant buds, etc.), thesediment contains the seeds or oospores* resulting from the sexualreproduction. By producing large offspring, vegetative reproduc-tive organs confer a competitive advantage (production) com-pared with seeds in their early stages of development. These organsare much less common in temporary habitats because of theirlower resistance to drying out.

The life expectancy of seeds is very variable from one plantspecies to another. Those which survive for less than one year(transitory stocks) do not accumulate over time and their num-bers present in the seedbank fluctuate very rapidly. Other specieshave long-lived seeds which tend to build up, in great numbers,in the sediment. Under the very variable environmental condi-tions in temporary pools, species and populations of plants haveevolved towards the production of seeds forming stocks whichpersist in the soil for more than one season. This long-lived seed-bank is of vital importance when the populations are subject tofrequent reproductive failure or when environmental conditionsare unfavourable for germination. Various strategies, including theproduction of a large number of long-lived, weakly dispersing

small seeds, with mechanisms to delay germination, has beenselected to facilitate the development of this seedbank (seeChapter 3f.)

Among aquatic annuals, the ability to produce seeds rapidly andin large numbers is vital for replenishing the bank of seeds orspores. Callitriche truncata germinates, grows and reproduces inunder 30 days, Ranunculus peltatus requires more time to repro-duce but can complete its reproductive cycle after the environ-ment has dried out thanks to its amphibious growth forms407. TheCharaceae require long periods of immersion to reproduce (Box 17).They do not complete their reproductive cycle every year butcompensate for this with a massive production of oospores duringfavourable years, associated with a low annual germination rate(maintenance of the stock).

The number of seeds produced by each species is correlated withits biomass41, 174. Also, the biomass accumulated by aquatic annualplants is itself correlated with the length of the growing season,determined by the dates of flooding and drying out172.

There are few specialised dispersal mechanisms among the plantsof temporary pools: it is as if there is less danger in remainingwhere the preceding generation has succeeded in reproducingthan in risking a dispersal which is very unpredictable in a rareand discontinuous environment. Klinkhamer et al.209 has shownthat the more likely species are to accumulate in a seedbank, theless well adapted they are to dispersal.

Box 18. Longevity of the seedbank Seedbanks increase the resilience of the vegetation of tempo-rary pools, i.e. their capacity to rebuild themselves following aperturbation60. Several studies of temporary pools have demon-strated the sporadic appearance (every three, five or ten years),sometimes in large numbers, of species such as Elatine bro-chonii or Damasonium stellatum, for example326. This depends onthe dormancy* and longevity of the seeds. Longevity is very varia-ble between species: sporocarps of Marsilea strigosa remainedviable after being kept in a herbarium for a hundred years84,whereas those of Isoetes setacea had lost their viability afterabout ten years in similar storage conditions (Michaux-Ferrière,pers. com.). In addition, it is probable that storage conditionsaffect this longevity and that it will be shorter in nature thanin a herbarium.In Australia, the viability of seedbanks of 21 species from sixdifferent pools was assessed: after 11 years only one samplestill gave rise to germinations and only two species (Juncusarticulatus and Myriophillum variifolium) continued to germi-nate61. The life expectancy of the seeds of most species fromAustralian pools is at least 3 or 4 years, but the average ormaximum duration remains unknown60. In the course of projects to restore two temporary pools insouthern France (Péguière in the Var and Grammont in theHérault), preliminary analysis of seed stocks showed that thecharacteristic species were no longer present (or were nolonger viable) after about 15 years (Grillas, unpublished) and30 years173 respectively.


Annual and amphibious, Ranunculus baudotii completes its reproductivecycle in the dry phase

Roch

é J.

47


Among temporary-pool species, dormancy* mechanisms limit thepercentage of germination in a given year41, reducing the risk ofpopulation extinctions365. The breaking of dormancy is partlycontrolled by environmental factors such as light, the degree ofwater saturation of the sediment, and temperature, but also byphysiological processes. In Elatine brochonii, Rhazi et al.324 havedemonstrated two factors controlling germination: water satura-tion of the sediment and light.Few data exist regarding the percentage germination rates of seedsfrom one generation over the course of a single hydrologicalcycle or flooding event. In Australia, Brock62 recorded very lowgermination rates (2.5%) during the first year after re-filling withwater while Bonis et al.42 reported much higher germination rates,varying between 30% for Charophytes and 50% for Zannichellia.Further, these authors noted that species capable of rapid germi-nation (non-dormant) as soon as the seeds are produced willenter into dormancy if they do not quickly experience conditionsfavourable for their germination. Some species (for example Calli-triche truncata) may possess, at the same time, a stock of young

seeds with high rates of germination and an older stock whichgerminate gradually. Information regarding the longevity ofseeds is scarce and sometimes contradictory (Box 18).

At a given site, differences may often be seen between the seed-bank and the surface vegetation. The presence in the seedbank ofspecies absent from the vegetation may indicate that the envi-ronmental conditions are not allowing these species to breakdormancy, that germination is being followed by failure, or thatsome species are being eliminated by competition with the com-munities that are already established. On the other hand, thepresence in the vegetation of species absent from the seedbankmay reflect a transitory seedbank, recent colonisation (oppor-tunistic), or solely vegetative reproduction* by some species.

The number of viable seeds in the bank, rather than counts of thenumber of shoots germinating in a given year (eminently variablefrom one year to another) is the best method for estimating popu-lation size.

Box 19. Key factors in the functioning and dynamics ofbryophyte* populationsThe most specialised suites of bryophytes are closely linked withthe alternating wet period/dry period regime. Most bryophytespecies of temporary pools are more or less temporary pioneers*with specialised strategies. The fugitive annual speciesa, annualshuttle speciesb as well as colonistsc are largely predominanthere. They are often ephemeral species (sometimes living only fora few weeks), generally producing spores in large quantities.These spores allow them to survive in a dormant form during thedry period. These species may also possess vegetative perennatingorgans. This is the case among many Bryaceae which produceone or several types of propagules* (tuberiform* propagules on therhizoids*, gemmiform * propagules in the leaf axils, etc.) and amongsome liverworts such as Phaeoceros bulbiculosus which havestalked bulbils on the underside of the thallus. The perennialspecies, truly stress-tolerant, are much rarer and strictly confinedto the outer zones of temporary pools where the shade fromtaller plants is greater and the soil a little deeper.

The usual morphological characters of xerophytic (drought-tolerant)species, such as the presence of scales, papillae or hairs, are notsufficient to explain the impressive resistance of the bryophytes,particularly liverworts, to the severe conditions of the dry season.Additional complex mechanisms, of a physiological nature, areinvolved. Anabiosis (ability to regenerate living tissue by rehy-dration of tissue which has been subjected to extreme desicca-tion) among a considerable number of bryophytes is probably theessential factor. Some species considered to be annuals can infact exhibit mechanisms of this type in certain conditions. Thethalloid liverworts and in particular the genus Riccia, as well asthe Pottiaceae, have many reviving species.

Owing to the drastic environmental constraints, bryophyte pop-ulations are very unstable in time and space and are subject towide variations in numbers from one year to another.

The importance of the bryophyte layer in the equilibrium of the“temporary pool” habitat is often underestimated. Mats ofPotiaceae, such as those of Pleurochaete squarrosa, a competi-tive perennial species frequently found around the edges ofpools, or the compact crusts formed by many thalloid liverworts,impede severe drying-out of the substrate during critical periodsand so to some extent favour Isoetion groupings. Other compet-itive perennial bryophytes may, on the other hand, promoteevaporation in the wettest basins by bringing a greater surfacearea of water into contact with the surrounding air (capillaryaction). Due to the significant amount of accumulated biomasswhich it constitutes, the bryophyte layer plays a considerablerole in the organic enrichment of the quasi-skeletal soils of manytemporary pools. During the unfavourable season, liverwortcrusts may also play a role in the protection of the sediment andits associated micro-organisms from external stresses (radiation,wind, erosion etc.).

Hugonnot V. & J.P. Hébrard

a. Fugitive annual species are ephemeral species with heavy investment in sexualreproduction (many sporophytes), no asexual reproduction, and small long-livedspores.b. Annual shuttle species are short-lived (but sometimes more than one year), withheavy investment in sexual reproduction (many sporophytes), no asexual reproduc-tion, and large spores (hence poor dispersal) with medium longevity.c. Colonists are short-lived species with heavy investment in both sexual andasexual reproduction and small long-lived spores.

48


d. Amphibians Jakob C. & M. Cheylan

Nature of the habitat, physical and biotic factors

Mediterranean temporary pools are very attractive habitats formost amphibian species due to several key factors: absence ofpredators (notably fish), absence of currents or sudden changesin the water level, and high spring temperatures resulting fromtheir shallow depth. The key factors in the breeding habitat ofamphibians have been the subject of many studies in the Medi-terranean region (see for example Pavignano292).The duration of flooding is a particularly important factor as itdetermines the time available for larval development, which itselfinfluences breeding success109, 194. Species such as the MarbledNewt, the Iberian Green Frog and the Western Spadefoot requirea long period of flooding to complete their larval cycle (2 to 4 months). In contrast, the larval development of the NatterjackToad or the Painted Frog is extremely rapid (minimum 30 days,see also Box 20). The depth of the pool strongly influences the length of theflooded period198. It often provides an indication of the potentialfor the presence of a given species, but this is not always the case for example in karst pools where fluctuations in water level

can be very rapid.The date of flooding also plays an important role for the rangeand number of species present at a site. Early flooding favoursspecies which breed early (Common Toad, Agile Frog, ParsleyFrog, etc.) but does not affect late species (Stripeless Tree Frog,Green Frog). In addition, some species take advantage of autumnflooding to breed (mainly Western Spadefoot, Parsley Frog andPainted Frog) while others do not (Common Toad, Agile Frog, Stripe-less Tree Frog, newts, etc.). The presence of aquatic vegetation will de decisive for somespecies292 such as newts and the Stripeless Tree Frog, in particu-lar for attaching their eggs113. On the other hand, it will be oflittle importance for others (Parsley Frogs, Western Spadefoots,Painted Frogs) and even unfavourable for species such as theNatterjack Toad which prefers poorly vegetated pools. Fringing vegetation will be preferred by species such as CommonTree Frog, the Common Toad, Agile Frog and newts, immaterial toPainted Frogs and Parsley Frogs, and rather unfavourable to theWestern Spadefoot or the Natterjack Toad.Shading of the pools is a favourable factor for species such asnewts116, 350 but unfavourable for others such as the NatterjackToad which prefers sunlit pools with a higher water tempera-ture28. However, the Marbled Newt breeds also in slightly shadedpools, provided the depth of the pool allows a favourable watertemperature.Nil or very low salinity is required by most amphibians. Hardlyany species apart from the Western Spadefoot, Painted Frog andNatterjack Toad will tolerate slightly saline water. Almost all species, except for the Common Toad and Green Frogs,are sensitive to the presence of predators, especially fish predatorsof eggs and tadpoles, which are generally absent from endorheic*temporary pools (Scoccianti355 for review).

Due to the close interdependence of these various factors it is dif-ficult to determine their relative importance. In addition it isdesirable to take other factors into account, such as the historyof the pool, its substrate, its geographic position and its land-scape context (degree of isolation in relation to other pools).

Box 20. Plasticity of reproduction of species in relation todates of submersion

In the face of the climatic vagaries of the Mediterraneanregion, different species have differing capacities to adapt.Some are flexible, in general those of Mediterranean originssuch as the Western Spadefoot, Parsley Frog and Painted Frog,while some are rigid, in general species of mid-European ori-gins such as the Common Toad and the Agile Frog333. The firstgroup are able to initiate egg laying several times per year, inresponse to heavy rain; the second group only lay once peryear, in general at the end of winter (February-March). Eachspecies therefore has a different reproductive phenology.Between-year variation in the date of flooding allows everyspecies to breed in one year out of two, on average, at a givensite. Such a biannual or multi-year cycle is well known foramphibians around the Mediterranean117, 181.

Jakob C.

Triturus marmoratus rolls up its eggs in the leaves of submerged plants

Chey

lan

M.

49


Instability of the physical environment and the requirements of the species for their annual cycles

The hydroperiod* is of great importance for the reproduction andsurvival of species over time. It largely determines breeding suc-cess and, hence, which species are present at a given site. AmongMediterranean batrachian communities, species are more or lessadaptable as regards the date and duration of flooding (see Box 20).Some species use the pools as soon as they fill with water, inautumn, for feeding (Marbled Newt, Great Crested Newt) or forbreeding (Western Spadefoot); others only at the end of winter(Common Toad, Agile Frog) and, lastly, others at the end of spring(Stripeless Tree Frog, Green Frogs). To these three categories maybe added the opportunist species such as the Parsley Frog andthe Painted Frog, which breed as soon as it rains, except in themiddle of winter or the middle of summer. The wide inter-year variability in the date of flooding of Medi-terranean endorheic pools may result in an absence of breedingin a given year for autumn or late-winter species (Box 21 andTab. 1 Chapter 2a). Breeding success may therefore vary betweenyears, a markedly different situation from that observed outsidethe Mediterranean region where amphibian breeding is, moreoften than not, annual. In general, this does not place the long-term

survival of the population in any danger due to the long-livednature of most of the species.The duration of the flooding period may also vary between years,with a considerable effect on the breeding success of the species(Box 22). A species that is well-adapted to Mediterranean poolswill be able to complete or accelerate its development up tometamorphosis to avoid early drying out, whereas a species witha long larval cycle will not be able to lay eggs or will be doomed tofail in its breeding that year. Finally, occasional flooding is of greatimportance for weakly competitive species, such as the Natter-jack Toad, which particularly seeks out pools that are depauperatein invertebrate predators and in other amphibian species.

Box 21. Variability in rainfall (1997-2000) and breedingamong amphibians in the pools of Roque-Haute(Hérault, France)In 1999, belated flooding of the 198 pools at the Roque-HauteNature Reserve (in May instead of October-November) resultedin practically a reversed situation among the amphibian com-munity compared with other years198. That year, the specieswhich colonised most pools in 1997, 1998 and 2000 wereunable to breed. Conversely, the species which usually occu-pied a small number of pools were able to breed more widely(Tab. 12). Early species such as the Marbled Newt and thePalmate Newt, as well as the late species, Green Frog, wereunable to match their laying date to the delayed flooding date.On the other hand flexible species such as the Natterjack Toadbred much more successfully that year.

Jakob C.

Scientific name English name 1997 1998 1999 2000

Bufo calamita Natterjack Toad 2 0 24 2

Hyla meridionalis Stripeless Tree Frog 42 29 39 35

Pelobates cultripes Western Spadefoot 16 1 4 0

Pelodytes punctatus Parsley Frog 23 17 10 0

Rana perezi Iberian Green Frog 9 10 0 1

Triturus helveticus Palmate Newt 40 39 0 27

Triturus marmoratus Marbled Newt 37 33 0 34

Year

Table 12. Number of pools containing newt larvae and tadpolesbetween 1997 and 2000 at the Roque-Haute Nature Reserve site.

Box 22. Duration and et flexibility of larval development In the Mediterranean region, the duration of larval develop-ment strongly influences breeding success. The larval cycles ofspecies found here may be long (newts, Western Spadefoot,Midwife Toads), short (Natterjack Toad, Painted Frogs) or inter-mediate (Parsley Frog, Stripeless Tree Frog, Green Frogs). Sincethe time for which the pool is filled depends on rainfall, thedrying-out of the breeding site may take place earlier in a yearof low rainfall, which will cause breeding failure among specieswith long cycles or late breeding. In response to these hazards,amphibians are able, to a certain extent (each species havingits own characteristic degree of response), to adjust the lengthof their larval development period to the duration of flooding110.In favourable years large young will be produced, and inunfavourable years smaller young. The lowering of the waterlevel also has the effect of raising the water temperature, whichallows larvae to accelerate their development. All these mecha-nisms combine to ensure that amphibians are well adapted tothe unpredictable character of the Mediterranean climate.

Jakob C.

A dried-out clutch of Pelodytes punctatus eggs in a prematurely dried-uppool

Chey

lan

M.

50


Spatial and temporal segregation

The pools form small, self-contained habitats which give risewithout doubt to manifestations of competition273. This compe-tition is partly reduced by two mechanisms: temporal segrega-tion and spatial segregation. Temporal segregation is stronglymarked for breeding dates (presence of adults), less marked asregards larvae. A study carried out in Spain showed that there isa significant difference between the breeding period of differentspecies but also within single species333, larger and more com-petitive males being the first to occupy the pool in order to mate.In southern France it is rare to observe more than two or threespecies of Anura breeding simultaneously at one site, contactsbetween species thus being limited. The combinations most oftenobserved involve the Western Spadefoot and the Parsley Frog inautumn, the Common Toad, the Western Spadefoot and the ParsleyFrog at the end of winter, or the Western Spadefoot and theNatterjack Toad in spring. Sometimes this overlap results in inter-specific matings, for example between a male Common Toad anda female Western Spadefoot, but these cases are uncommon.Spatial segregation reinforces the isolation of the breedingadults, particularly in the case of a network of pools (Box 23). Inthe case of single pools used by several species (up to six speciesof Anura in southern France), spatial segregation is usuallyobserved during egg laying. At the Fertalières pool (Hérault), lay-ing by Western Spadefoots and Common Toads is always locatedat the same sections of bank from one year to another, with fairlywell-marked separation of the two species. In the same way, tad-poles of Natterjack Toads, Parsley Frogs and Western Spadefootswill not use exactly the same vegetation zones within a pool: thefirst two species will be confined to the pool margin, in shallowerareas, and the third to the middle of the pool, in the deepestparts.

e. InvertebratesThiéry A.

Many studies have been concerned with the richness of macro-crustacean communities in temporary habitats, in several coun-tries subject to various different climatic influences, in Europe9,

52, 282, 410, Australia26, 218, the USA168 and Africa49, 106, 147, 148, 189, 250. Onthe other hand few studies have been carried out into their func-tional aspects. Hydrology nevertheless appears as one of the keyfactors: it determines the presence, composition and structure ofthe biocenoses (flora, fauna etc.), and regulates the aquatic inver-tebrate communities.

Habitat structure

Three principal hydrological parameters may be distinguished: theduration of flooding, water quality and the time (season) at whichflooding takes place.The duration of flooding is determined by climate (amounts ofrainfall, etc.), soil (type, permeability etc.), the depth of the pool,and the presence of and distance from groundwater. It is directlyinvolved in community structuring as a result of the resident-migrant duality among the fauna, as defined by Giudicelli & Thiéry166

(Chapter 2d). According to data collected at temporary pools froma range of Mediterranean Basin countries (France, Morocco, Algeria,etc.), colonisation develops375, 377, 380 in accordance with four moreor less distinct phases:A. A pioneer stage with low species richness, dominance of resi-dent species with dormant stages and a few migrant species(fewer than five),B. A stage of increasing richness through arrivals of migrantspecies (Heteroptera, Coleoptera, Diptera, etc.),C. An equilibrium stage (progression of life cycles, reproductionetc.),D. A phase of senescence, where emigration and the disappear-ance of some resident species with short cycles (Anostraca,Cladocera, Rotifera, etc.) may be observed.

Based on this model, the duration of flooding will determinewhether or not these successive phases can develop. This dynamicmodel is still theoretical and needs to be tailored according tothe range of different situations:• In the case of ephemeral habitats (flooded for less than threeweeks, Fig. 15a), the faunistic richness is poor. The invertebratefauna is represented only by some crustaceans with short cycles(cyclopoid copepods) a few worms, and generalist* Diptera (Chiro-nomidae, Culicidae etc.) which come to lay eggs as soon as theydetect any water. Some Coleoptera, such as Agabus nebulosus,may rapidly colonise the new habitat and prey heavily upon theyoung microfauna206. In these habitats the species diversity islow, due to the proliferation of a few species (vacant ecologicalniches, nutritional resources in excess). • In temporary pools (flooded for one to three months, Fig. 15b):the pioneer species are present, including in particular some anos-tracan macrocrustaceans (Branchipus, Lindiriella, etc.) which areable to reproduce here owing to the longer period of flooding.This is followed by the second phase with the arrival of migratoryinsects. This period is characterised by a richness which increaseswith time. Diversity increases due to the numerical re-balancingof the different species following the establishment of trophic*

Box 23. Spatial and temporal segregation in pools atDoñana

Diaz-Paniagua114, 115, 116 was able to observe the larval periods of10 species of amphibians over six years in a network of 16temporary pools in the Doñana National Park (southwestSpain). The species which laid eggs earliest in the season, i.e.in autumn, were Discoglossus galganoi and Pelobates cultripes.Over the course of the study, these two species showed thewidest variation in the date on which laying began, dependingon annual variations in the flooding of the pools. The spatial segregation of the species depended mainly on thedepth of the pool. Three groups were identified: a group whichbreeds in the most ephemeral pools, thereby avoiding the otherspecies (Bufo calamita and Discoglossus galganoi), a groupbreeding in temporary pools which remain flooded for a fairlylong time (Triturus marmoratus, T. boscai and Hyla meridionalis),and a group using pools which are flooded for a long time,even permanently (Pelodytes punctatus, Pelobates cultripes,Bufo bufo, Rana perezi and Pleurodeles waltl).

Jakob C.

51


relationships (food chains). The optimum point attained by thecurve depends on the date of drying out.• In pools with a longer duration of flooding (three to eightmonths) richness continues to increase and all four phases maybe observed (e.g. at Bonne Cougne). Over 100 species may some-times be noted in the biotope, albeit with time-lags due to vary-ing dates of arrival and different lifespans. Over the course oftime, a succession of populations may be observed211, 218, 363, 375, 377,

380, 410 (Fig. 16). Within the biotope segregation is also spatial, dueto the varying ecological requirements of the different species

Figure 16. Succession of populations of cladocerans Daphnia, Simo-cephalus and Chrydorida illustrating the trophic* non-competitionwithin a single pool (based on Laugier227)

Figure 15. Structure of invertebrate populations in temporary pools in relation to the duration of flooding, a) ephemeral pool, b) temporary pool

12

7

45

6

3

1 - Oligochaete annelid2 - Nematode3 - Anostracan4 - Cladoceran5 - Cyclopoid (female with eggs)6 - Chironomid larva7 - Coleopteran (Agabus nebulosus)

MigrantsResting eggs

1 2 3

4 5

6

7

8 9

10 12 1314

15

1617

18

1920

11

1 - Annelid 2 - Ostracod3 - Caenis larva (Ephemera)4 - Anisopteran larva (Odonata)5 - Corixid6 - Notostracan (Triops)7 - Aquatic mite8 - Trichopteran larva9 - Chironomid larva10 - Notonectid (Heteroptera)

11 - Gyrinus (Coleoptera)12 - Gerris (Heteroptera)13 - Anostracan14 - Hydrophilid

15 - Dytiscid Coleopteran 16 - Coleopteran larva 17 - Clœon larva (Ephemera)18 - Cladoceran

19 - Calanoid 20 - Harpacticoid

MigrantsResting eggs

14

12

10

8

6

4

2

0

Num

bers

.L-1

Time (days)

0 1,5 3,5 5,1 6,8 8,8 10,5 12

Daphnia

Chydoridae

Simocephalus

a)

b)

52


(planktonic, benthic etc.). In a temporary pool, competing speciesare rare owing to the diversity of microhabitats and of feedingmethods (carnivores, filter feeders, grazers, detritivores, etc.). Thislow level of competition results both from the time lag affectingdifferent growth stages and from habitat preferences (Fig. 16).For example, if two anostracans coexist at a time t, one will beat the breeding adult stage (Branchipus schaefferi or Tanymastixstagnalis) while the second will be at the juvenile stage (slow-growing Chirocephalus diaphanus). These two species exploit dif-ferent food resources382 according to their anatomical differences(distances between the bristles on their foliaceous appendages*).

Geographical factors

Light conditions (pools in open country v. pools surrounded bywoodland, etc.) and accessibility for migratory insects and birds(see Box 29, Chapter 3f) play an important role in species com-position and diversity. Interchanges of fauna (connectivity*) dependsalso on the distance between the pool and other aquatic biotopes,temporary or permanent10 (network of canals, rivers, lakes, pondsetc.). Temporary pools function rather like islands125, 380 with, inparticular, species richness linked with the surface area of thepool (Fig. 17). As with island habitats, the processes of speciationare observed with greater frequency than for continuous habitats,with the appearance of endemic* species27 such as Linderiella,Tanymastigites, Tanymastix, Branchipus, etc.

Water quality

Physiological requirements of the aquatic invertebrate fauna(excretion and respiration) partly determine their potential pres-ence in a pool. Osmotic regulation is dependent on the mineralcontent of the pool (salinity, hardness, etc.), which varies betweensites but also over the course of an annual cycle. Most freshwater*invertebrates do not survive in water with a conductivity greaterthan 1.5-2 mS.cm-1. Osmotic processes also influence the hatchingof the resting eggs of branchiopod and copepod crustaceans.Hence any pollution (nitrates, phosphates, chlorides, etc.) endan-gers the survival of these species. Temperature and dissolved oxy-gen content are limiting factors for survival (see Boxes 24 and 25).

Figure 17. Evolution in the number of invertebrate species in rela-tion to the diameter of the pool (based on Giudicelli & Thiéry166)

Box 24. Temporary pools: overheated habitats? Because temporary pools are shallow and have only sparseplant cover, conditions within them may on occasion be incom-patible with aquatic life. Temperature acts directly on thephysiology of invertebrate organisms (poikilotherms*) but alsoindirectly through its effects on the solubility of oxygen.During warm periods, when the water temperature in the poolsmay exceed 30°C in the daytime, the crustaceans Triops, forexample, are close to their lethal limit, corresponding to thetemperature threshold for the precipitation of protein. Suddendisappearances of whole populations may occur in a few hourswhen the water temperature exceeds the threshold of 32-33°C(Thiéry, original data).If the rate of development accelerates and fecundity increases,this is compensated for by a reduced size of individuals atmaturity and by reduced longevity380. The temporary pools ofarid areas are particularly characterised by the turbidity oftheir water. In turbid temporary pools in Israel414, NewZealand26 and the USA132, the existence of microstratification,with a decrease in temperature of 8 to 10°C at a depth of 20 cm(± 2 cm), had long remained unexplained. Thiéry380 has accountedfor this stratification in the dayas of western Morocco. Insummary, particulate organic material adsorbed onto suspendedclay traps solar radiation and, depending on pH, remains in sus-pension due to increased viscosity of the upper layer of water(epilimnion). The 20-cm deep water layer which has absorbedheat during the daylight remains at the surface during the night,without mixing with the deeper layer. This deeper layer there-fore maintains its night-time temperature, i.e. 8 to 10°C lowerthan the surface. This deep zone (hypolimnion) provides a ther-mal refuge for crustaceans, which congregate there during thedaytime.As drying out steadily proceeds, this microthermocline disap-pears and the water column becomes thermally homogenous.In response to the marked increase in temperature, crustaceanswill produce thermo-protective proteins, “Heat Shock Proteins”(HSPs) which allow them to survive for a few hours at more than36°C (1 hr at 40°C for Artemia). This corresponds to a metabolicresponse to heat stress as shown by the studies of Artemia byMiller & McLennan266 and of Lepidurus by Jean et al.202.Increasing water temperature also plays a role in the activityof insects, by triggering waves of flight and migration amongthe Corixidae for example (Sigara, etc.). Conversely, warmwater at 20 to 25°C will be sought out by insects at the limitof their biogeographical range, for example the case of speciesof “Ethiopian” origin such as the anisopteran odonateCrocothemis erythraea122, 123, the heteropteran Anisops sardea,and the coleopteran Eretes sticticus, wrongly considered to beendemic to Provence.

Thiéry A

0 20 40 60 80

100

90

80

70

60

50

40

30

20

10

0

Tota

l inv

erte

brat

es r

ichn

ess

Diameter of the pool (m)

53


During major algal blooms in the warm season (spring and sum-mer), dissolved oxygen deficits at night may become lethal forcrustaceans380.

Macrophytes

The final factor of importance for the invertebrate macrofauna isthe presence of submerged macrophytes. These act as microhabi-tat refugia, dividing up the water column and creating a more het-erogeneous habitat which favours increased biodiversity399. Asobserved by Aguesse2, rice fields are suitable for Ischnura elegans,I. pumilio, Crocothemis erythraea and Sympetrum fonscolombei.In general, the diversity of the vegetation and of the hydrophytes*is a decisive factor influencing the odonate richness of a pool120.Emergent plants provide large surfaces colonised by a sessile*microfauna which will be a nutritional resource for grazinginvertebrates (Micronecta, Sigara, etc.). For their part, the Chara-ceae play an important role in trapping sediments and helping to

clarify the water70, 342, 404, which has variable effects depending onthe crustacean species. Cladocerans, for example, benefit froman increase in water clarity. Characeae also metabolise calcium and carbonates for use in theconstruction of their vegetative structure and so play a part invariations in water quality (see Box 13, Chapter 2a).While the dynamic phases A and B described above are only slightlyvegetated (inhibited germination, slow growth, etc.), macrophytesconstitute a decisive factor in the development of animal com-munities during phases C and D.

Development of temporary pools in the medium andlong term

Over time, at the decade scale, the temporary pool does notremain stable, but undergoes changes in its morphology (siltingup, etc.) which lead to changes in the structure of its biologicalcommunity.

Box 25. Dissolved oxygen and temporary habitats

In temporary habitats, the dissolved oxygen content of the wateris one of the principal factors limiting the survival of the inver-tebrate fauna. While most animals are not affected by supersatu-ration above 150%, subsaturation levels of less than 20%, evenfor a limited period (sometimes for a few hours during the night),constitute lethal thresholds.

In temporary pools, oxygen levels vary in time and in relation tothe presence of submerged plants380 (Fig. 18). The submergedvegetation (Ranunculus, filamentous algae Spirogyra, etc.) tendsto produce high diurnal levels of O2 in the water (photosynthe-sis) and low values at night (plant respiration). Aquatic plantswith emergent leaves (Eleocharis, Carex, Isoetes, Glyceria, etc.)only have a slight effect. In addition, given the physical lawsrelating to the solubility of gases, the available oxygen decreasesas the water temperature increases. When their habitat becomesoxygen-poor, the aquatic invertebrates respond in various ways:• by stages of life with lower metabolic rates to limit their needfor oxygen,• by modifying their biological activities and behaviour (locomo-tion, etc.),• by synthesising respiratory pigments that are better able tobond with oxygen. This is the case for some crustaceans, insectsand molluscs. Branchiopod crustaceans (Triops for example) arecapable of synthesising extra-cellular haemoglobin149. In theanostracans Artemia there are three types of haemoglobins,capable of bonding reversibly with oxygen, which give them theirred colouration in anoxic conditions107, 268. Pulmonate gastropodmolluscs such as Planorbis, as well as the larvae of the chirono-mid dipterans Chironomus of the plumosus and thumni group,also have this ability413.

As well as producing haemoglobins, crustaceans are able toadapt their biological activity by increasing the rate at which

their swimming appendages beat (forced ventilation throughincreased volume of water bathing the gills). They modify theirbehaviour by reducing their consumption of dissolved oxygen134

as well as by vertical migrations among the anostracans271, turningupside-down in the case of Triops (which makes use of the mostoxygenated fringe of water at the air/water interface) and accu-mulation in the deepest and hence coolest part of the poolamong notostracans. One study has shown that Triops andLeptesteria have very low lethal thresholds, close to 10% of satu-ration, levels which are only rarely encountered in the naturalenvironment380.

Martin C. & A. Thiéry

Figure 18. Evolution during the course of a day in the oxygen dis-solved and in the pH in open water and in a vegetation bed(Moroccan pool) (based on Thiéry380)

Diss

olve

d ox

ygen

(m

g.L-

1 )

16

15

14

13

12

11

10

9

8

7

67h 9h 11h 13h 15h 17h 19h

■ Ranunculus ■ Isoetes ■ Open water

Box 26. Monitoring a population: the case of the GreatCrested Newt at the Valliguières site in the Gard (southernFrance)

Context: The Great Crested Newt population of the Etang deValliguières (Gard) constitutes one of the last remaining popula-tions in southern France. Accordingly, this pond has beenincluded in the Natura 2000 network of sites in accordance withthe Habitats Directive118. Since January 2000, this population hasbeen subject to monitoring within the framework of LIFE“Temporary Pools”.

Problems: This pool is flooded sporadically and in response toheavy rains which supply the subterranean water of karstic ori-gin (Box 12, Chapter 3b). In only five out of the past eleven yearshas the flooding lasted long enough (drying out in July-August)to allow successful breeding. In 2001, the population consistedentirely of adults, giving rise to fears of a rapid decline. The ques-tions which then arose were therefore the following: What is thepopulation size? Is it stable or decreasing? Is breeding once everytwo or even three years sufficient for the long-term survival ofthe population? Is it possible to increase the population sizeand/or its breeding success to reduce the risk of extinction?

Methods used: A Capture-Mark-Recapture (CMR) protocol wasinitiated in January 2000, based on one visit every 15 days duringthe period when newts are present at the site (approximatelyNovember to May, with wide annual variations in the period ofpresence). Newts were captured at night with a pond net andindividually identified using the black markings on their under-sides (individual photo-identification). Thirty-four visits to thesite resulted in 645 captures comprising 216 different individuals.

Results: The population size was estimated as 199 individuals in2001 (177-237) and 119 in 2002 (110-133) with a total of 213individuals over the two years, confirming the hypothesis of asmall population (about 100 breeding females). The size distribu-tion confirmed the absence of juveniles in the population in2001. Estimates of demographic parameters (adult survival rate,recruitment* rate) do not permit precise modelling of the futureof the population. A further year of monitoring will be necessary.However, the results already show that, with an adult survivalrate estimated to be between 59% and 88% per year, the prob-ability of extinction of the population is very high. It would onlybe able to maintain itself if the adult survival rate were high(88%/yr) and if at least 56 individuals were recruited every threeyears approximately, which is a high value but no doubt feasiblein practice. In the absence of any intervention in the habitat(maintenance of a two- or even three-yearly flooding cycle) arecruitment of about 30% at each successful breeding will benecessary to maintain the population. With annual breeding, therecruitment rate necessary to stabilise the population is no morethan 15%.

Given the hypothesis of successful breeding every two years, thepopulation has a 95% chance of sustaining itself for longer than100 years if adult survival is constant at 88% and if, at a mini-mum, 32 individuals are recruited into the population every twoyears (Fig. 19). In view of these findings, the LIFE “Temporary Pools” project hasidentified several management actions which will favour themaintenance and survival of the newt population: digging outthe pool to extend the flooded period and to allow the larvae tosuccessfully metamorphose more frequently, the creation of addi-tional pools to boost numbers of newts and to reduce the risks ofextinction, management of the vegetation cover to facilitate themovements of the newts during their terrestrial phase and placingpiles of stones close to the banks to protect emerging juvenileamphibians from wild boar.

Cheylan M., K. Lombardini & A. Besnard

54


f. Population dynamics and genetics P. Gauthier & P. Grillas

Introduction

Temporary pools are discontinuously distributed. In the same wayas islands, they are separated by very different habitats. For

species strictly dependent on these pools, the analogy withislands is relevant; populations are isolated, often fluctuating,and with a poor capacity for dispersal. On the other hand, for lessspecialised species, the pools may constitute secondary, more orless long-lasting habitats. The pools are therefore populated bothby species which strictly depend on this habitat and by otherswhich make use of it in an opportunistic way.It is mainly the biology of populations of specialist temporarywetland species which is considered here: those which do nothave a refuge or a population source outside temporary pool

Figure 19. Probability of extinction of an isolated Great Crested Newt popu-lation subjected to drying out with varying regularity (based on Besnard32)

Nighttime capture and individual recognition of Triturus cristatus atthe Etang de Valliguières

Gen

dre

T.

1

0,8

0,6

0,4

0,2

0Extin

ctio

n pr

obab

ility

at

50 y

ears

Everyyear

Everysecond year

Everythird year

Every fourth year

Frequency of years with early drying out = reproduction failure

Initial number: 200 individuals

Initial number: 50 individuals

55


habitats or those which are obliged to complete a part of theirlife cycle here.

Knowledge of the biology of these populations and an evaluationof their genetic diversity are indispensable for their managementand long-term conservation. It is generally accepted that thecapacity of a population to adapt is linked to its genetic diversity.Conversely and paradoxically, a close local adaptation to extremeconditions may result in a decrease in genetic diversity. In orderto evaluate the genetic diversity of the populations of a species,several key parameters need to be taken into consideration: thehistory of the populations, their size, their degree of isolation, thetype of reproduction (cross- or self-fertilisation), the characteris-tics of gene flow and the existence of local adaptations.Prioritisation of populations in relation to their level of interestmay prove necessary, to direct the choices of managers towardsone population or another when not all, for example, can be sub-ject to conservation measures. In this context, conservation biol-ogists in the 1980s devised the concept of the EvolutionarySignificant Unit or ESU: a population unit which merits specificmanagement and high conservation priority, on the basis of alevel of adaptive variation determined from ecological and/orgenetic data94.

Populations often small and isolated

The probability of extinction is greater in small populations, andparticularly in a fluctuating environment such as in temporarypools. In these habitats populations are often completely or partlydestroyed, for example by early flooding or drying out (the caseof the Great Crested Newt, Box 26), which takes place before theyhave been able to complete their breeding cycle.

In small populations, raised levels of inbreeding (genetic drift) maylead to the accumulation of unfavourable mutations which couldpossibly lead to extinction. This is generally accompanied by adecline in the capacity for adaptation (selective value) of indi-viduals.

Small population sizes therefore constitute a risk for species dueto the risk of chance extinction linked to severe environmentalfluctuations and to the reduction of the capacity to adapt as aresult of inbreeding. Some of the biological characteristics ofspecies such as the type of reproduction (cross/self-fertilisation),dispersal (of pollen and seeds) or size of the seedbank for plants,may accentuate or reduce this risk.

Consequences of isolation for reproduction and dispersal

The isolation and small size of the populations impose strongconstraints on their dynamics. For individuals, the issues are topass on descendants capable of maintaining the population andto disperse them among several sites to avoid the risks of acci-dental local extinction. Sexual reproduction incurs costs286 due to the necessity of search-ing for partners and due to the fact that only one copy of thegenes is passed on. In compensation, it reduces the inbreedingdepression*, thereby increasing the “quality” of the descendantsand their chances of being successful. Many animal and plant

Box 27. The paradox of Artemisia molinieriArtemisia molinieri is a rare species, endemic to three temporarypools in the Var and classified as in danger of extinction261, 285.The two main populations of this wormwood are confined tothe temporary lakes of Gavoty (Besse-sur-Issole) and Redon(Flassans-sur-Issole), included in the LIFE “Temporary Pools”project. Torrel et al.389 carried out an ecological and genetic study ofthe two main populations of Artemisia molinieri with the aimof evaluating the threats faced by the species and of formu-lating conservation measures. The results were as follows: • At the two sites Artemisia molinieri is very abundant (severalthousand individuals) and is the dominant species.• Genetic diversity is unexpectedly high for a plant with sucha limited geographical distribution. In addition there is no indi-cation of any genetic imbalance (drift).• The two populations, 4 km apart, are genetically very simi-lar, which indicates that there is gene flow (interchange ofpollen or seeds) between them, or that they have only recentlybecome isolated.• Levels of pollen viability (10% at Redon and 30% at Gavoty)and of seed germination (4% and 14% respectively) are low inboth populations. The low fertility of the Redon population maybe partly linked to infection of the inflorescences by a fungusand to environmental conditions (high concentration of nutrients*,irregular flooding, anthropogenic effects, grazing, etc.). In these conditions, Artemisia molinieri propagates itselfmainly vegetatively, by means of its vigorous stolon system.The low sexual reproductive rate appears to be sufficient tomaintain dense populations and a wide genetic diversity. Torrelet al.389 concluded that the conservation measures should prin-cipally involve maintaining the condition of the two lakes(legally protected status and/or acquisition by a public body)combined with continued monitoring of the populations. In 2000, half of Lake Redon was ploughed, destroying part ofthe Artemisia molinieri population and allowing the appearanceof species of high natural-heritage value, such as Lythrum tri-bracteatum, Damasonium polyspermum and Heliotropium supi-num1. This lake is extensively grazed by 200 sheep. Finally, Artemisia molinieri is paradoxical in that it is a rarespecies with the habit of a dominant, exclusive species: thefuture of the other species beneath the covering of Artemisiamolinieri is uncertain. Given its high degree of endemism,Artemisia molinieri presents a conservation issue of high prior-ity compared with equally protected but much less rare specieswith which it shares its habitat.

Gauthier P., D. Rombaut & P. Grillas

Artemisia molinieri, an endemic but dominant species at Lac Redon(Var, France)

Roch

é J.

56


species of temporary pools are able to multiply without using crossreproduction: some invertebrates are parthenogenetic (Box 28)and self-fertilisation is common among plants. In temporary poolsin the San Diego area (USA) for example, 12 species out of 20 areautogamic*417. At the Roque-Haute Nature Reserve, the popula-tions of Scirpus maritimus (auto-incompatible) produce no or fewseeds due to their isolation and to the lack of pollen originatingfrom neighbouring pools75.The specialist plant species of temporary pools tend to dispersetheir pollen and fruits less effectively than the generalists* (seebelow). With reduced rates of gene flow, there should be a greaterdegree of differentiation between populations than for the gene-ralist species. The poor dispersal (a few centimetres or tens ofcentimetres) may result in the appearance of genetic differenceswithin a single pool. Indeed, Linhart236 demonstrated the exis-tence of adaptive genetic differentiation between populations ofVeronica peregrina separated by two to five metres in temporarypools: plants in the centre of the pool were adapted to strongintraspecific competition in a wet, predictable environment,while those at the edges were adapted to a high level of inter-specific competition in a drier, more unstable environment. Dispersal leads to the colonisation of new sites and prevents theextinction of species or of genes. Eggs and seeds allow the dis-persal of individuals while the mobility of pollen or gametesensures the dispersal of genes. In the short term, in particular inisland habitats, the capacity for dispersal may be selected against:the probability of success for a plant may be greatest in the sameplace where previous generations have grown. Populations colo-nising new isolated habitats may very rapidly lose the character-istics favouring their dispersal. A reduction in dispersive capacitywas observed among several species of Asteraceae on smallislands after only about ten years following their introduction69, 83.Low numbers facilitate these adaptations. This reduction in dis-persal mechanisms has also been observed among the plants oftemporary pools417 (Fig. 20).At the scale of the Mediterranean, the colonisation of verywidespread sites by similar suites of plants and animals never-theless suggests that long-distance dispersal does take place, viabirds, the wind, etc. Spores, seeds and invertebrate eggs may becarried, sometimes over great distances, in the soil stuck to birds’feet, or may pass undamaged through their digestive systems143, 308.

This is likely to facilitate the colonisation of new sites and theflow of genes between populations. In arid or semi-arid environ-ments where temporary pools are the preferred stopover sites forwaterbirds208, the dispersal distance will depend on the durationand the length of their flights. Over shorter distances, other ver-tebrates such as cattle380, wild boar, rats48 or rabbits418 are alsoagents for the dispersal of seeds or macrocrustacean eggs. Therole of amphibians should be studied40, 380.

Champeau & Thiéry74 observed the transport of crustacean eggsby Saharan winds from North Africa to southern Europe. Theyexplained the existence of a south-north gradient in the distri-butional area of some species as resulting from a gradient in fall-out rates related to the mass of the eggs. The heavy eggs ofTriops numidicus fall out, for example, in Sicily and Majorca whilesmaller eggs, such as those of calanoid copepods, fall out furthernorth, towards Corsica (Fig. 21). The seeds of Elatine brochoniiare so small that they may be assumed to be carried by strongwinds.

Figure 20. Percentage of species with no dispersal mechanism andwith mechanisms for the retention of seeds in the plants of tempo-rary pools and other habitats in California (based on Zedler417)

Box 28. Parthenogenesis: an efficient means of populatingthe habitat

1. When flooding commences, the resting eggs of Cladoceraburied in the sediment hatch and each gives birth to two amic-tic females (diploid but incapable of mating).2. These females give birth by parthenogenesis to young (ovo-viviparity) or to eggs capable of hatching immediately. Theseeggs hatch to produce amictic females and so on. This type ofreproduction has the advantage of producing a large number ofindividuals at the lowest cost (3 to 45 per female depending onspecies and environmental conditions).3. When the environmental conditions become more severe(increase in solute concentration, temperature etc.) the amicticfemales produce mictic females (diploid and capable of mating),as well as males (often of smaller size than the females).

4. Fertilised by a male, the mictic female lays a dormant eggwhich requires a maturation phase (sufficiently long period ofdrought) before hatching. These eggs persist for a few months toseveral years, buried in the sediment while the environmentalconditions remain unfavourable, before hatchingParthenogenesis is a common phenomenon in permanent (stable)habitats where some populations (cladocerans, rotifers) candevelop in the complete absence of males and dormant eggs. Onthe other hand, when the conditions become more severe, thesex ratio (ratio of the number of males to the number of females)is close to unity and the survival of the species depends mainlyon the production of resistant stages through sexual reproduc-tion.

Gauthier P. & A. Thiéry based on Peters & Bernardi295

■ Species from the other habitats■ Species from temporary pools

100

80

60

40

20

0Species without

dispersal mechanism for seeds

Species with seeds retention

mechanism

Perc

enta

ge (%

)

Deterioration in environmentalconditions: light, [ions] , [02] , T° ,populations density

57


2 - Increase by already hatched eggs orovoviviparity

2 - Increase in the number of amictic females (2n)

3 - Appearance of small males (2n)and mictic females(2n)

4 - Cross fertilisations = resting eggs (sexual)

Is c

arrie

d ou

tx

times

1 - Hatching of amictic females Water level

■ Water■ Sediments

[ ] Concentration02 OxygenT° Temperature

DecreaseIncrease

Figure 22. Cycle of Cladocerans/Daphnidae

Figure 21. Distribution map for the fallout of crustacean resting eggs on a size gradient (Modified, based on Champeau & Thiéry74)

Maxi ø 600 µmMaximum distance of fallout of Triopnumidicus cysts

High altitude saharianwinds 600 - 1500 m

Maxi ø 100 µmMaximum distance of fallout of calanoidcopepods cysts

Calanoid copepodsTriop numidicus0 500 km

58


The seedbank, population dynamics and genetics

In the very variable environmental conditions of temporary pools,some species of plants and crustaceans have evolved to produceorgans which persist for more than one season in the soil (Chapter 3,Box 32) to form banks of seeds, spores or eggs. These banks allowpopulations to persist even when there are repeated reproductivefailures over several consecutive years. In Morocco, for example,the years when Elatine brochonii appears in the dayas (Fig. 23)are the years with most rainfall, the seeds remaining dormantduring the other years326.

The bank of seeds or eggs increases the effective size of popula-tions and their genetic diversity. By increasing genetic diversityand by mixing together in a given year individuals from severalpreceding generations, the bank reduces the rate of evolutionary

change (acting as a brake on evolution) and limits the risk of arapid reduction in diversity64. In temporary aquatic habitats, thebanks minimise the consequences of fluctuating population sizesand allow the maintenance of their genetic diversity.The genetic diversity of the existing vegetation does not repre-sent a random sample of that of the seedbank128. It results fromselection which may originate, for example, from the eliminationof consanguineous individuals (counter-selection) or from differinggermination rates depending on genotype* (environmental ger-mination filter).

Management implications

Estimating the size of populations is of fundamental importanceduring the implementation of management measures. It is oftenconsidered that a threshold level of 100 actually breeding indi-viduals is necessary in a population243, i.e. 300 to 1000 poten-tially breeding individuals. Below this threshold, populations runa serious risk of extinction after 50 to 100 generations as a result

Box 29. Dispersal by birds

In the temporary pools of the Doñana National Park (south-west Spain), Figuerola143 studied the transport of seeds, sporesand eggs by birds. He observed a significant level of externaltransport, on the plumage and feet, of six bird species: twoducks, two wading species and two rallids. Seeds adhere morereadily to the plumage and eggs to the feet. Even some seedslacking dispersive adaptations (Ruppia) were transported.

Internal transport also played an important role, with about65% of bird droppings collected containing undigested, viablepropagules*, belonging to seven plant genera as well as crus-taceans and bryozoans. Waterbirds were still consuming andtransporting a large number of propagules in mid-winter, fivemonths after the peak of seed production144. During pre-migratory fasting, birds increase the retention time of thepropagules (16 hours), thereby increasing their dispersal dis-tance. Waterbirds are probably the main dispersal agents foreggs and seeds within, to and from the temporary pools ofDoñana169.

P. Gauthier & P. Grillas

Figure 23. Interannual variation in the abundance of Elatine brochonii in two dayas in Morocco

Box 30. Population genetics of Marsilea strigosa atRoque-Haute

Marsilea strigosa is a rare species, endemic to certain tempo-rary pools of the Mediterranean Basin. Its genetic variabilityhas been analysed at the scale of the whole of the Medi-terranean and at the scale of the very fragmented metapopu-lation* at the Roque-Haute Nature Reserve (Hérault, France).The studies show that Marsilea strigosa is self-fertile. At theMediterranean scale, marked differentiation between popula-tions implies very limited or no gene flow. More surprisingly,gene flow appears also to be very limited between the variouspools at Roque-Haute, despite their close proximity (a few tensof metres in general). The superficial similarity of the pools toone another conceals a marked degree of genetic variability inthe Marsilea strigosa populations: some of them only containone genotype* whereas others include all the genotypesrecorded at Roque-Haute.

based on Vitalis et al.406

9876543210

1997 1998 1999 2000 2001 2002 2003

Mea

n ab

unda

nce

9876543210

1997 1998 1999 2000 2001 2002 2003

Mea

n ab

unda

nce

Daya of Benslimane Large pool of Mamora

59


Box 31. Rare or threatened species

There are several ways of being rare (Tab. 13). For very specifichabitats such as temporary pools, the rarity of species will bemore especially linked to the rarity of their habitat (rarity interms of distribution rather than numbers). Isoetes setacea, forexample, is found only at a few scattered sites, but often in largenumbers328. However, rare species with small numbers of indi-viduals may also be found in temporary pools (for exampleMarsilea at Roque-Haute) which, in addition to the scarcity ofpotential sites, have to face demographic and genetic problems

associated with the limited number of individuals. Rare orthreatened species often have low or zero levels of genetic vari-ability, generally resulting from the passage of populations throughgenetic bottlenecks which limit the intra-population diversityand from the absence of gene flow between the residual popu-lations. It is generally considered that a specialised species,highly adapted to a particular habitat, will be more vulnerablethan a generalist* species. However, the increasing rarity of thisfavourable habitat (isolation) will select for genes which conveya decreased capacity for dispersal, which in turn has a goodchance of favouring adaptations appropriate to the site.

Gauthier P.

Size of populations Species with a wide distribution range

Species with a small distribution range

Species with a wide distribution range

Species with a small distribution range

Locally high Common Illecebrum verticillatumIsoetes velataCallitriche brutia

Artemisia molinieriRanunculus rodieiApium crassipes

Everywhere low Knickxia commutata Marsilea batardaeMorisia monanthos Damasonium bourgaei

Marsilea strigosa

Pilularia minuta Teucrium aristatumLaurenbergia tetranda

Non-specific habitat Very specific habitat

Ranunculus ophioglossifolius

Table 13. Types of rarities in some plants present in temporary pools (based on Rabinowitz et al. 317)

of the increased probability of the occurrence of deleteriousmutations. The protection of populations with numbers lower thanthese thresholds cannot be guaranteed, and management activ-ities should concentrate on increasing their numbers.The size criterion is often decisive in deciding whether or not apopulation requires reinforcement. This assessment will be facili-tated if the following are known: the degree of geographical iso-lation, the history of the population, the mode of reproduction ofthe species being studied, the dispersal of propagules* or pollen, theevolutionary history of the species and its populations (increasingor declining), and the existence of a seedbank.Knowledge of the genetic diversity of the population may alsoprove to be important. In the long term, a low level of geneticvariation (drift) may decrease the potential for adaptation by thepopulation to environmental changes. However, populations havinga low level of local genetic diversity may be important in main-taining the overall variation of a species, particularly if they reflectlocal adaptations.

Depending on the specific case, various management principlesshould be applied for the reinforcement of temporary pool popu-lations. In the case of residual populations, reinforcement based on indi-viduals originating at the same site (after ex-situ breeding) or at

very close sites should be favoured, to retain local adaptationsand especially to avoid failures associated with the poor degreeof adaptation of introduced populations. Reinforcement usingmore distant populations may nevertheless prove necessary if thelocal populations are too genetically impoverished or cannot beproduced ex-situ (numbers too reduced, uncontrolled cultivationor livestock rearing). In the case of metapopulations* (for example newts, see Box 33),interchanges may be more readily considered, especially amongsites within the metapopulation.

During reintroduction projects carried out following local extinc-tions, the source populations should be chosen with care, espe-cially in relation to parameters of habitat, geographical proximityand ecology.In terms of the overall conservation of species, the markeddegree of isolation of the populations must be taken into con-sideration. The greatest possible number of populations will needto be preserved to ensure the survival of the widest possible rangeof genetic and phenotypic diversity of the different species. Whilesome populations must inevitably disappear, it would seem essen-tial to protect those which are in good functional condition, i.e.of a sufficiently large size, breeding regularly and, in the case ofplants, having a bank of viable seeds.

60


Box 32. Predicting the unpredictable: drought-resistingstrategies in invertebrates

For an aquatic species, life in a temporary pool entails respond-ing or adapting to the disappearance of its natural habitat. Mostinsects emigrate to leave a biotope which has become inhospitableor to colonise a new biotope. However, a significant proportionof aquatic invertebrates have developed adaptive strategies, amongwhich the production of resistant forms (ecophases*) is one of themost remarkable. These organisms are classified as residents, asopposed to migrants.

Many resident taxonomic groups are able to colonise temporarypools, such as sponges (Spongilla) Cnidaria (hydroids), Platy-helminthes (Rhabdocoela of the genus Mesostoma), nematodes,the Oligochaete annelids Naididae and Tubificidae, rotifers, thebryozoans Plumatillidae, and among the crustaceans, Branchio-poda (Cladocera), Ostracoda, and cyclopoid, calanoid and harpacti-coid copepods.

Various modes of resistance may be distinguished:Type 1: Dormant diapause* eggs are found in branchiopod, ostra-cod and copepod crustaceans, ephippia in cladocerans, stato-blasts in bryozoans and gemmules in sponges. (Fig. 24).Type 2: Dehydration of adults or larvae may be observed innematodes (Fig 24) and bdeloid rotifers. Larval or adult stagesmay also survive with reduced metabolic rates in the sediments;this is true of the larvae of Odonata (Sympetrum striolatum: fiveweeks in the sediment190), chironomid Diptera (Polypedilumpharao375), and Coleoptera which will pupate in dry conditions,such as Berosus375. The reactivation of these quiescent* organismsis directly stimulated by the rehydration of the sediments.Type 3: Quiescent* (also called dormant) larval stages amongcalanoid copepods resume their development immediately waterlevels begin to rise.

Type 1 resistant forms fulfil several functions:• the provision of an egg bank similar to the seedbank, allowingrapid colonisation of the habitat as soon as water appears; crus-taceans are the first to colonise the pool and are in this respecttrue pioneers*,• dissemination by wind (anemochory*) and by animals (zoo-chory).The eggs of cladoceran and anostracan branchiopods have spe-cific structures and morphologies (Fig. 25), enabling species to beidentified278, 287 even when the habitat has dried out (Chapter 6f).

Thiéry A.

Spongiae Bryozoan NematodeDaphnia(cladocera crustacean)

BranchiopodTriops

0

100 µm

0

100 µm

0

200 µm

0

100 µm

0

500 µm

Figure 24. Invertebrate resting eggs

1. Branchinella spinosaThe Caban marsh

2. Linderiella massaliensisEndemic to 4 pools of Provence

3. Branchipus shaefferi4. Chirocephalus diaphanus5. Tanymastix stagnalis6. Imnadia yeyetta7. Lepidurus apus

21 3

4

5 7

200 µm100 µm

6

100 µm

Figure 25. Morphology under a scanning electronic microscopeof the cysts of seven species of macrocrustaceans in the Provenceregion

61


Box 33. Inter-pool movements by newts In the network of pools at the Roque-Haute Nature Reserve,Jakob196 individually marked 470 Marbled Newts (Triturus mar-moratus) using electronic tags, allowing their movements tobe tracked from 1998 to 2000 (Fig. 26 and 27). In a single year,newts moved an average of 27 m and a maximum of 163 m toreach another flooded pool. Between years, the mean distancemoved was 33 m and the maximum 168 m. A study in theRhône valley (Lyon) at pools separated by increasing dis-tances264 showed that the migration distance between popu-lations of Alpine Newts (Triturus alpestre), Palmate Newts (T. helveticus) and Great Crested Newts (T. cristatus) is rela-tively short. Complete isolation could be observed amongpopulations separated by more than 350 m.

Jakob C.Monitoring by radio-tracking the movements of Triturus marmoratus atRoque-Haute

Jako

b C.

Figure 26.Movements of Great Crested Newtsmarked and recaptured during aperiod of flooding (1998) at Roque-Haute

1 19

1

11

1

3

14

124

1

152

36

20

Number of newts whichmoved to another pool

Number of newts marked at the first capture campaign

62


Figure 27. Interannual movements of Great Crested Newts marked and recaptured at Roque-Haute (between 1998 and 1999, between1999 and 2000, and between 1998 and 2000)

0 m

62 m

40 m

0 m

0 m

17 m

30 m

14 m

88 m

168 m

43 msol

Movements in m

0 35 m

0 m

0 m

63

4. Threats to Mediterraneantemporary pools Gauthier P., P. Grillas & M. Cheylan

Temporary pools often have a scattered distribution and becauseof their small surface area are potentially easy to destroy. However,from a historical perspective, human action on pools has beencontradictory: on the one hand, multiple anthropogenic pressuresdegrade or destroy pools; on the other hand, many pools are of arti-ficial origin, created for various purposes, including watering holesfor livestock373 (Box 34). Today, despite the absence of precisedata, it is clear that the destruction and degradation of Medi-terranean temporary pools occurs more frequently than theircreation.

The hydrological characteristics (duration, depth, dates) and lowproductivity (few nutrients*, summer drought) of temporary poolsare the most important factors for the conservation of the speciesand characteristic communities they contain (See Chapter 3).When they affect these factors, human activities have an impacton the conservation of the species which they host. A distinctionshould be made between damage leading to the direct destruc-tion of pools (urbanisation, infilling, etc.) and degradations orperturbations (for example partial drainage, pollution) which,though less irreparable, still modify their ecological functioning.The introduction of invasive species, the closing-up of the habi-tat and natural aggradation* also disrupt the delicate balancebetween these habitats and the species they contain.

Although most of the threats faced by temporary pools are com-mon to the whole of the Mediterranean region, a contrast can beobserved between the countries of the North and those of theSouth. As they were useful for an agricultural economy based onextensive exploitation, the pools are of limited interest today inmost European regions, where they have been abandoned ordestroyed284, 373. In the countries of the South, however, theyretain their usefulness in the current economic context. Theirimportance, however, risks being reduced as a result of economicdevelopment.

Destruction of sites

Over the past 50 years, there has been a vast increase in urbani-sation around the Mediterranean, related to demographic growthand the development of tourism. Temporary wetland areas in peri-urban habitats are faced with the threat of infilling during hous-ing or road development. In Languedoc-Roussillon, the majority oflocal declines and extinctions of rare plants have been caused bythe direct destruction of habitats (urbanisation) and the intensi-fication of land use228. Near Agde, the Rigaud pools disappearedduring the construction of a housing estate260 and those at Notre-Dame de l’Agenouillade (Agde, Hérault) are surrounded by urban-isation. The pools of the Plateau de Vendres (Hérault) and Rodié(Var) have been degraded or partially destroyed by road infras-tructure. In Malta as in Morocco, the disappearance of pools fol-lowing urbanisation is frequent near towns21, 222, 322. The increasing rarity of sites has significant consequences for popu-lations, notably of amphibians, by reducing the extent of inter-change between populations and thus their long-term survival

Box 34. Temporary pools in southern France: a balancethat is sometimes positive in terms of quantity but alwaysnegative in terms of quality

There is no current research enabling the decline of temporaryhabitats to be measured. Also, though in some sectors ofsouthern France such as the Massif des Maures (Var) or theCausse d’Aumelas (Hérault) there are certainly more creationsthan disappearances, these are not of equivalent quality. In theMassif des Maures and Plaine des Maures, pool creation hastwo main functions: small water cisterns for the Défense desForêts Contre les Incendies (DFCI) and pools used for huntingpurposes. Some support good populations of amphibians,especially pioneer* species (Natterjack Toad, Common Toad,Parsley Frog) as well as rare species (Spadefoot). On the otherhand, they are of little interest from the botanical point ofview, as they are often dug into soil and are therefore muddy.On the Causse d’Aumelas, many pools used for hunting purposes,which are also attractive to some amphibians, have been createdover the last 20 years without any destruction of pre-existingpools being observed (Lavognes type, see Chapter 2a).In Languedoc, Chaline72, who in 2001 continued the invento-ries of pools conducted in 1974 by Gabrion153, observed thatsix pools out of the 94 studied had disappeared. At the sametime, far more pools had been created. Among those, Chalinedistinguished:• Pools used as watering places, usually covered and thus notvery interesting for fauna and flora (essentially on theCausses).• Pools used for hunting purposes, small, frequently concrete-lined, generally fairly deep and more or less unvegetated. • The hill reservoirs used by the DFCI, supplied by rivulets,generally deep and fairly large in size.These new types of pools attract some pioneer amphibians ofunstable habitats (Natterjack Toad, Parsley Frog) or generalist*amphibians (Common Toad, Palmate Newt, Stripeless Tree Frog)but are globally less rich than the traditional pools of thisregion.

Cheylan M.

On the Plaine des Maures, the construction of a golf course has destroyednumerous temporary rivulets with Isoetes duriei

Roch

é J.

64


(Chapter 3d). In some cases, the disintegration of the landscapecan lead to the total extinction of all species. This is the case, forexample, in the Ebro Delta in Spain where, following extremeartificial modification of the landscape, all amphibians have nowdisappeared, even the most resilient species such as the IberianGreen Frog (Santos, pers. com.). In contrast, the Camargue Deltahas lost none of its original species, thanks to the preservation ofimportant natural areas.

Hydrological perturbations

In the Mediterranean region, public-health interests have justi-fied the draining or infilling of pools, which as “sources of disease”are feared by humans. Similarly, pools have been dried out inMorocco263 and Malta182 to combat mosquitoes (Anopheles labran-chiaei), vectors of malaria.Temporary wetland areas are also filled in or drained to increasearable areas. Intensification of agriculture was the main causefor the disappearance of pools in Spain between 1955 and 1980(Medina, pers. com.) and in the Costières Nîmoises (France) duringthe same period310. Pumping from the water table for agriculture and the supply ofdrinking water to urban areas, for example in the Donãna NationalPark in southwest Spain357, Malta182 and northeast Algeria105,leads to the early drying-out of these habitats, thus imperillingtheir characteristic communities of plant and animal species.

The extraction of raw materials for construction results in anincrease in the duration of flooding and turbidity of pools inMorocco, accompanied by their impoverishment in rare species325.The creation of reservoirs for irrigation or fire protection (DFCI),by overdeepening or banking up, causes permanent flooding oftemporary habitats. Several pools which host rare crustaceans(Branchipus cortesi) have thus been overdeepened in Portugaland have lost their temporary ecological nature244. The Saint-Estève pool in the Pyrénées-Orientales and the Grammont poolnear Montpellier have also been transformed into permanentpools following hydrological modifications in their catchmentarea11, 230, 284. These hydrological changes lead to a reduction infloristic richness, notably of bryophytes* (Hugonnot & Hébrard,pers. com.) and to the disappearance of rare species and theirreplacement by a more invasive aquatic flora based on helo-phytes* (Typha latifolia, Scirpus maritimus, etc.). However, an increasein the duration of flooding of the pools can prove to be favourableto the aquatic fauna (amphibians, insects, crustaceans) by enablingit to complete its breeding cycle.

Perturbations by fire

Fire is a major disruptive factor in the Mediterranean region. Itsimpacts, though little studied, are probably variable: direct on thefauna, flora and seedbank, and indirect on the hydrology, sedi-mentation and exotic species, for example. In the case of tempo-rary pools and streams, fire has positive effects in the sense thatthe destruction of woody species and the opening-up of the land-scape favour Mediterranean species. It also has negative effectson populations and on the habitat (infilling by ash and silt, etc.)which can affect all of the species present.

The plant biomass, the date of the fire and the dampness of theground are factors likely to affect the temperature of a fire andits consequences for the species and their perennating organs.Perennials possessing rhizomes or underground bulbs are resis-tant to the passage of fire. Thus Artemisia molinieri does not seemto be affected by the winter burning of its dry stems. Similarly,large rushes or Scirpus produce new leaves in the weeks followinga fire. The passage of fire probably has a more significant destruc-tive impact on superficial seedbanks and perennials lacking under-ground perennating organs (Cistus, for example).

Box 35. Roads: impassable barriers

The construction of linear infrastructure (roads, motorways,railway lines, etc.) inevitably causes the destruction of numer-ous forests, meadows and wetland areas.Roads cause heavy mortality among amphibians. This has beenassessed at between 34 and 61% whilst crossing a road withtraffic of 3200 vehicles per day, and from 89 to 98% on a motor-way (traffic greater than 20,000 vehicles per day)184. After astormy night, 456 Palmate Newts, 314 Stripeless Tree Frogs, twoNatterjack Toads and two Marsh Frogs were found squashed on60 metres of a road with little traffic, near Montpellier79. A majorongoing study, begun in Catalonia in 2001 should enable thismortality to be measured throughout the whole of a region239.Impassable for many amphibian species36, 231, roads are barrierswhich reduce or remove the opportunities for interchangebetween the populations situated on either side of them353.This isolation makes the populations more vulnerable to therisk of extinction, whether this is due to genetic or demo-graphic causes or random environmental accidents412. Over thelast 15 years, two of the four populations of WesternSpadefoots known in the Var département have thus beenwiped out with no hope of recolonisation, given the distancesseparating these sites from the nearest populations. InGermany, populations of Common Frogs (Rana temporaria)have shown genetic impoverishment following the creation ofa motorway320.

Gauthier P. & M. Cheylan

Banalisation of the vegetation at the Grammont pool (Hérault, France)following its permanent flooding

Tan

Ham

L.

65

4. Threats to mediterranean temporary pools

By opening up the habitat, fire favours the establishment of exoticpioneer species162. The destruction of the belt of woody speciessurrounding pools could explain the spread of Dittrichia viscosain the pools of Tre Padule de Suartone in southern Corsica241, 242.Modifications to nutrient dynamics and the level of released toxiccompounds (phenols, tannins) have not been studied ; nonetheless,they also constitute potential threats for species.

In Catalonia, a study in the Garraf Natural Park has shown a reduc-tion in the species richness and abundance of amphibian larvaein pools affected by fire with significant differences betweenspecies: the Stripeless Tree Frog (Hyla meridionalis) was the mostaffected, while the Parsley Frog and Iberian Green Frog were onlyslightly affected82. Tree-dwelling species are more sensitive tofire than the species of open habitats, which are less affected, andeven favoured in the mid term. In the Serra de Grândola (Portugal),one year after a fire, the amphibian community was significantlyaltered with a notable reduction in the number of urodeles Triturusmarmoratus and Salamandra salamandra92. In the Maures, imme-diately after a fire, one of the rare species still present is the MarshFrog (Rana ridibunda), an invasive species with a high reproduc-tive capacity (Cheylan, pers. com.). However, the time scale is tooshort to assess the mid-term impact of fires on amphibians. Toovercome these shortcomings, a study is planned on the pools ofthe Natura 2000 site “Bois de Palayson-Colle-du-Rouet” followingthe fires of the summer of 2003.

Fires can also modify the hydrological functioning of temporarypools and streams (increase in the flooding regime, evapotranspi-ration, etc.) through increased erosion of the catchment area andthe input of sediments resulting from this (for example in theMaures80, 260, 311). In small streams with shallow beds, a temporarilyhigh flow can remove most of the sediment. On the other hand, inlarger streams the sediments persist for a long time in deep basins,thus modifying their hydrological characteristics (capacity to sup-port the European Pond Terrapin, for example). In pools, sedimentaccumulation increases with the size of the catchment area.Indirectly linked to fires, forestry operations for reforestation andthe development of fire defences, by altering the topography of theground, can compromise the functioning of the hydraulic networkof temporary pools and streams (for example, the hydrological net-work of the Bois de Palayson or the Plaine des Maures260).

Invasion by competitive plants (woody plants, helophytes*,etc.)

The cessation of agricultural practices, particularly the extensivegrazing of livestock, results in the “closing-up of the habitat”, i.e.the colonisation of herbaceous habitats (grasslands, meadows) bywoody species. A simple increase in the density of herbaceous coverconstitutes a threat for less competitive annual plants (Box 49,Chapter 5c) and for amphibians dependent on open landscapes:Western Spadefoot (Pelobates cultripes), Natterjack Toad (Bufocalamita) or Parsley Frog (Pelodytes punctatus). The bryophytes oftemporary pools only survive for a very short period when they aresubjected to shade or competition with colonising grasses(Hugonnot & Hébrard, pers. com.). On the other hand, irregularlygrazed habitats are often very rich in bryophytes. Flooding (height and duration) limits the expansion of woodyspecies into temporary pools. However, species tolerant to floodinggrow on the border and in the shallow areas of the pools. The

spread of woody species in and around temporary pools generallyresults in the cessation of grazing by livestock. This causes areduction in solar radiation and in temperature, which can slowdown the growth of herbaceous plants (Box 46, Chapter 5c). Inaddition, shade, reduction in wind speed and water temperaturereduce evapotranspiration in winter and thus tend to increase theduration of flooding. Conversely, the presence of certain specieswhich are major consumers of water can lead to a great increasein evapotranspiration during the growth season and acceleratethe drying out. Pools are thus dried out by the planting ofEucalyptus, as is the case in Portugal for paper production244, 300,or in Morocco for timber or firewood, or in order to “clean up” thesezones, which are often considered as unhealthy (Rhazi L., pers.com.).

Input of nutrients

The direct input of nutrients into pools is probably rare in Franceeven though the margins of some pools are cultivated. SomeMoroccan dayas, on the other hand, are still used for washing bylocal populations who introduce phosphate-rich washing powders(Rhazi et al., 2001). The accumulation of livestock faeces withinpools or their immediate periphery is also a potential source ofnutrients, the impact of which remains to be evaluated.When temporary pools take the form of islets in the middle of largecereal fields or vineyards, agriculture represents a threat throughits indirect inputs of fertilizer via run-off water or undergroundwater. The accumulation of nutrients from agriculture has beenobserved in the clayey substrate of Moroccan dayas325.

A number of laboratory experiments have shown that amphibianlarvae feed less, move less quickly and exhibit imbalances, mal-formations and an increased mortality rate when low levels ofnitrates and nitrites are added to the water249, 409 (Box 36). InSpain, three species of amphibians have been revealed to be verysensitive to ammonium nitrate: Common Tree Frog, Painted Frogand the Common Toad287. In the Common Tree Frog, a mortalityrate of 30% has been observed for concentrations of 50 mgL-1

(legal concentration permitted for human consumption). The otherspecies, though less sensitive, nonetheless show slower growthas well as developmental anomalies.

At Roque-Haute (Hérault, France), the growth of woody plants, following thecessation of grazing, has had a negative impact on populations of Isoetessetacea

Roch

é J.


Box 36. Amphibians and chemicals

The eggs and larvae of amphibians are particularly exposed totoxic effects in aquatic habitats but the adults, in aestivation orhibernation, can also be contaminated. Depending on the species,the stage of development and the level of contamination of thehabitat, amphibians assimilate toxic agents through differentroutes: the skin, inhalation and/or direct or indirect ingestion(consumption of the target insects of the pesticides). Even thoughthe concentrations of pesticides in the environment rarely reachthe lethal doses determined in the laboratory, sub-lethal effectscan have serious consequences particularly for the larvae (mal-formations, disrupted feeding or movement, delayed growth,etc.) leading, sooner or later, to their disappearance (Fig. 28).In amphibians, pesticides can interact with the endocrine system.The temperature, UV-B radiations and pH are known to amplifytheir harmful effects. Also, it seems that the presence in theenvironment of several chemicals may have a cumulative effect.

When pesticides must be used in an agricultural area, it is par-ticularly important to avoid breeding periods (phases of migra-tions to and from breeding sites, the presence of eggs and larvaein the water, dispersal phase of juveniles) and migration (move-ments of adults between summer and winter sites), and to exer-cise caution in applying the substances to avoid unnecessarycontamination of surrounding areas, including pools. Improvingagricultural techniques and limiting the risks of contaminationby filtering the discharge water before it can reach water bodiesare two fundamental strategies to limit contamination. Creatingbuffer zones on the margins of cultivated areas is one of themost effective means of reducing contamination.

Gauthier P. & M. Cheylan based on Scoccianti355 et Blaustein & Kiesecker35

Figure 28. Possible effects of agri-cultural chemical substances onamphibian populations

Use of agrochemicals(pesticides and fertilizers)

Exposure of amphibiansto lethal doses

Death

MalformationsAssimilation through

the trophic chain

Decreased foodsupply

Alterationin activity

Decreased feedingintake

Decreased predatoravoidance ability

Delay in growth anddevelopment

Further delay in development

Longer period of time when the larvae are

vulnerable

Death caused by drying up of

breeding site beforethe completion of

developmentDelay in metamorphosis with possible

repercussions on the survival rate of newly emerged juveniles

Predation

Decreased intra and interspecific competition

ability

Longer period oftime when the larvae

remain in the contaminated site

Exposure of amphibiansto sublethal doses

Effect on other species

(insects, etc.)

66

67


Enrichment by phosphorus and potassium can also cause eutro-phication of pools, induce algal blooms and favour competitiveplant species to the detriment of rare and characteristic species.Béja and Alcazar29 suggest that the proliferation of Reedmace(Typha sp.) in pools in Portugal results from an increased con-centration of nutrients. Pollution can also be of urban origin: in central Spain146 and inMorocco (Rhazi, Thiéry, pers. com.), the channelling of urban wastewater into temporary wetland areas has been observed. The Opoulpool (Pyrénées-Orientales, France) was used, in the past, as anoutlet for a domestic-water purification site210, 284, although wedo not know if these inputs have had detrimental consequencesfor the batrachians or the flora.

Toxic pollutants and dumps

With the purpose of combating malaria, insecticide products arepoured directly into pools (in Morocco263). Indirect inputs can resultfrom various human activities in the catchment area, notably thepesticides used in agriculture. Roads are sources of various typesof pollution, whether as a result of accidents involving vehiclestransporting toxic products, by road leachates with a high hydro-carbon content or by products used for road maintenance (her-bicides, salts, lime, etc.). In the case of karstic wetland areas, theorigin of the contamination can be much further away than thesuperficial catchment area would suggest (Chapter 3b). The degreeof contamination of a site varies above all according to the quan-tity of chemical products per unit surface area, as well as the sizeof the surface treated and the persistence of the substances. It isnot unusual for the concentrations of toxic substances in smallisolated pools (closed systems) situated near agricultural zonesto be higher than in larger wetland areas where water renewal isgreater.

Throughout the Mediterranean, temporary pools are used as dumpsfor waste and rubble. This dumping leads to a decline in the char-acteristic bryophytes and causes the appearance of nitrophilousland-based communities with Barbula unguiculata, Funariahygrometrica, etc., which are very commonplace ruderal species(Hugonnot & Hébrard, pers. com.).

The accumulation of pesticides in run-off water represents a highrisk for amphibians (Box 36) and aquatic invertebrates166 (Box 37).In some cases, it seems that amphibians have good capacities ofresistance to polluting agents. The establishment of amphibianpopulations in motorway stormwater tanks (Scher, pers. com.), andthe persistence of a diverse population in the Opoul pool in thePyrénées-Orientales, which receives water from a vineyard whichundergoes frequent chemical treatments284, seem to indicate this.

Physical disturbance of the sediment

Physical disturbance of the habitat (burrowing of wild boar in thesediment, trampling by livestock, the passage of vehicles, input ofsediments to the catchment area, digging, etc.) can have, dependingon the situation, positive or negative effects on the conservationof the flora and fauna of temporary pools. Physical perturbationscan contribute to the reduction of the plant cover and thus, indi-rectly, favour annual or not very competitive species. When theseperturbations become too frequent, particularly during the growing

Box 37. Pesticides and dragonflies

The quality of surface water has been greatly degraded for sev-eral years now, and dragonflies now seem less numerous; somespecies even appear to have disappeared101. Recent studies58

show that a number of pesticides chronically contaminate rain-water, particularly Atrazine (herbicide), DEA (deethylatrazine),Alachlor (herbicide), Lindane (γ-HCH) (insecticide) and its iso-mer β-HCH. Pesticide levels in water can sometimes exceedseveral tens of mg per hectare (in Atrazine and Alachlor).Though few studies exist in the Mediterranean region, data isavailable in the surrounding region showing the great sensitivityof dragonflies to pesticides during their aquatic life, i.e. at thelarval stages.Methoprene, an insect growth regulator used to combatmosquitoes, causes a reduction in Odonata populations56, 362.Similarly, carbamates affect seven genera of Zygoptera andAnisoptera164. After seven days of application of Diflubenzuron,Zgomba et al.420 observed a 72% mortality rate in Odonata inYugoslavia. Applications of Bacillus thurigensis, BT serotype H-14,cause similar reactions. The same results have been observedon populations of chironomid Diptera305. Organophosphates cause the death of dragonfly larvae in lessthan two hours. Fenthion, Bromophos and Lindane are highlytoxic to Zygoptera (Lestes sponsa, Ischnura elegans, Coena-grion puella) for which a mortality rate of 40% was recordedin populations in less than 48 hours212. High concentrations ofRotenone eliminate Aeschnidae. Generally speaking, in contami-nated water the density of Odonata is reduced by 30% com-pared with natural habitats370. In Germany, in the Hamburgregion, only two species, Coenagrion puella and C. pulchellum,had survived out of the 14 recorded 25 years earlier183.With regard to ricefields, pesticides have been the subject ofrecent studies: Schnapauff et al.349 show in Greece a negativeeffect of Propanil (N-(3,4-dichlorophenyl)-propionamide)associated with Parathion (an organophosphate) on the popu-lations of Ischnura elegans. In the Camargue, Suhling et al.366

observed that Sympetrum fonscolombii and Orthetrum cancel-latum are clearly affected by treatments which combineIcazon and Alphamethrine (a pyrethroid). Suhling (com. per.)puts forward the hypothesis that Sympetrum depressiusculum,which will soon be added to the IUCN Global Red List andwhose larvae used to develop in the ricefields of the Camarguein the 19603 disappeared following the use of insecticides. Inthe Camargue, Fipronil, the only insecticide currently autho-rised, is also suspected of causing a reduction in numbers andchanges in population structure in half of the species presentin ricefields155 (Crocothemis erythraea, Orthetrum cancellatumand O. albistylum).Odonata larvae are good indicators of water quality369, 253.Long-term monitoring of Odonata populations is thus of greatimportance for habitat management. However, as dragonfliesare known for their great capacities for flight, an inventorybased on the occurrence of adults is not relevant. The prove-nance of adults should be verified by the study of the larvaeand exuviae, which give proof of successful breeding in thebiotope.

Thiéry A.

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season of plants, they can reduce the size of populations, frag-ment them and prevent plants from completing their cycle andreproducing. Generally speaking, analysis of the impact of per-turbations should be made by considering the type of perturba-tion and the potential impacts on both sensitive populations andcompetitive species. The creation of ruts by the repeated passage of vehicles, particu-larly of all-terrain vehicles (cars, motor bikes), can alter the hydro-logical functioning of pools. Thus, for example, in the Padulellupool near Porto Vecchio (Corsica), following the repeated passageof 4x4s, run-off increased in the catchment area, resulting in thesite of Elatine brochonii being covered with gravel241. At other sites,localised trampling leads to excessive subsidence of the substrateand causes a decline in most species of bryophytes (Hugonnot &Hébrard, pers. com.) and of characteristic angiosperms*. Thus inthe Chevanu pool (southern Corsica) which serves as a car parkin the summer, the numbers of the annual Lythrum borysthenicumdropped by around 90% between 1991 and 2003 (Paradis & Pozzodi Borgo, unpublished).

On the southern shores of the Mediterranean, the large popula-tion increase of recent decades has led to an increase in livestocknumbers causing, in Morocco and Algeria, considerable damageto pools and neighbouring natural habitats81, 263, 339. Despite theextensive rearing methods used here, the animals concentratearound the pools. The intense trampling of the livestock breaksdown the soils323 which become very unstable, increasing turbid-ity and reducing the light available for plants. In the pools of theforest of Mamora (Rabat, Morocco), the turbidity caused by thepassage of livestock seems to explain the poor development ofaquatic and amphibious vegetation during the submerged phase.

Sedimentation

Temporary pools are shallow habitats, which make them potentiallyvery sensitive to infilling by sedimentary deposits. These depositsare partly the result of natural processes, the speed of which area function of the nature of the substrate, the intensity of rain-water run-off (gradient, permeability), the extent of the catch-ment area and the balance between the processes of depositionand erosion. These processes can be accelerated by human activi-ties (see above, this Chapter). Sedimentation can be predominantlymineral or organic. In the second case, organic material can arisefrom the pool itself in situations of high productivity (litter fromhelophytes, trees, etc.), from the periphery, or from the catchmentarea. Infilling contributes to the reduction in the number of rare speciesand the establishment of competitive herbaceous species (Scirpusmaritimus, Phragmites australis, Paspalum ssp., Dittrichia viscosa,Typha, etc.) and/or woody species, through the reduction of thestress linked to flooding and an increase in the productivity ofthe habitat. The establishment of these productive plants alsocontributes to the drying-out of temporary pools357 through theaccumulation of organic material and an increase in evapotran-spiration. In North Africa, in some cases the processes of infillingof the dayas will be slowed down by the effect of whirlwinds which,during the dry phase, lift and carry off the sedimentary particlesaccumulated at the bottom of the basin263, 323, 380.

Alluvial deposits constitute a particular threat for bryophytes:when a temporary pool is tending to fill in and lose its alternating

regime, the 15 to 30 species characteristic of the submersion/drying-out cycle disappear and leave room for a succession ofcommonplace species, which are not very numerous and are non-specialised, forming dense cover. In these conditions, one encoun-ters Amblystegium riparium and Drepanocladus aduncus, whichform a carpet of entangled stems, or Bryum pseudotriquetrum forexample. These species generally accompany the large helophytes(Typha or Scirpus) (Hugonnot & Hébrard, pers. com.). The deposit of a litter of tough leaves, of Cistus for example, canbe a serious obstacle for smaller herbaceous plants, notably the ter-ricolous bryophytes (Hugonnot & Hébrard, pers. com.) or Isoetes328

which become covered up.

The impact of invasive species

Colonisation of pools by competitive, often ruderal, exotic plantscan engender competition with the characteristic species of tem-porary pools. Poirion & Barbero303 reported the colonisation ofnumerous pools and cupules of the Esterel and the Biot massif (Var)by a very virulent South African plant, Freesia alba. In the Maures,Paspalum dilatatum, Panicum capillare and Euphorbia prostrata,the two first species being mainly propagated along the roadnetwork, colonise areas of sedimentary accumulation at the bot-tom of streams and pools (Medail, pers. com.). These species con-tribute to the loss of habitat and should thus be monitored evenif, given their primarily summer or autumn growth season, their

Impact of ploughing and grass-cutting on Artemisia molinieri at Lac Redon(Var, France)

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impact on the other species of temporary pools probably remainslow. In Corsica, there is another South African species, Cotulacoronopifolia, which seriously affects most low-altitude wetlandareas280, notably the temporary pool of La Tour d’Olmeto (Paradis,pers. com.). The permanent flooding of temporary pools and the installationof low volume dams on temporary streams are generally followedby the introduction of fish, often exotic, which constitute a majorthreat for amphibians4, 51, 98, 154, 258, 272. For example, in Provenceduring the 1960s, the pond at Saint Rémy in the Alpilles sup-ported several natural-heritage species for the region (Triturushelveticus, Alytes obstetricans, Pelobates cultripes, Pelodytespunctatus), which have today totally disappeared because of theintroduction of fish (Peyre, pers. com.). A similar observation hasbeen made in the region of Cantabria, the Province of La Coruña(Spain), in Algeria and in Languedoc, where the number of amphi-bians in sites with fish is much lower than that observed in siteswithout fish. Mosquitofish (Gambusia affinis), introduced into France,Spain and Algeria in the 1970s to combat mosquitoes96, 136, 340, areregularly found in temporary pools where they have a negativeimpact on certain species of zooplankton (Daphnia spp). In the tem-porary marshes of the Camargue, the accidental introduction ofThree-spined Stickleback (Gasterosteus aculeatus) through irriga-tion canals has caused the gradual extinction of the largest andmost visible (coloured) zooplankton species which are characteris-tic of these habitats304.The explosion of populations of Louisiana Crayfish (Procambarusclarkii) has had direct negative effects on the vegetation of tem-porary pools and indirectly on the animal species colonising thesehabitats by reducing their food resources and impairing their refuge

sites (see, for example, in the Doñana National Park179). In the Pauldo Boquilobo Nature Reserve (Portugal), 13 species of amphibianscould be observed up to the beginning of the 1990s100, 319. Elevenyears after the establishment of the Louisiana Crayfish, only fourspecies could be found, with numbers clearly lower than thoseobserved during the first inventory in 1993. Only Bufo calamita,dependent on very ephemeral pools, not colonised by the crayfish,has increased locally. The impact of the Louisiana Crayfish is some-times exacerbated by the introduction of exotic fish with signifi-cant effects on populations of amphibians such as in the Provinceof La Coruña (Spain)154 and in the Alentejo Natural Park in south-west Portugal29.

In general, these predators attack the eggs and larvae of the mostsensitive amphibian species. Some species, however, show resis-tance to these predators, either through the toxicity of their larvae(Bufo bufo), or by avoidance behaviour (Rana sp., some urodeles).In addition, most batrachians detect the presence of fish bychemical recognition191, which enables them to avoid the sitescolonised by the fish. This avoidance, however, results in a loss ofbreeding sites, which accelerates the decline of the species.

Impact of domestic and game fauna

Wild and domestic herbivores have dual and contradictoryeffects: they can compromise the survival, growth and reproduc-tion of plants yet they also reduce competition and create sitesfavourable to the regeneration of weakly competitive species (seeabove, this Chapter “Invasion by woody species”). Negative effects

Box 38. Damasonium alisma and ploughing

Devictor112 compared the seedbanks of Damasonium alisma inpools situated on fallow land with those of pools situated incultivated areas. Despite a density of plants three to five timeshigher in the cultivated areas than in the fallow areas, theaverage number of seeds in the soil bank was the same in bothareas (an average of about 300 seeds per 250 g sample). In thefallow land, the seeds were found mainly on the surface, whilein the cultivated areas they had a more homogenous distribu-tion through the soil profile. The germination rates of the seedsfrom the fallow land were 70% and 45% respectively for sur-face and deep horizons, and in the cultivated zone 40% and80% for surface and deep horizons.

Ploughing can explain this contrasting distribution. In the cul-tivated part, the seeds produced in the summer, with high ger-mination capacity, are buried by ploughing in the autumn andthe seeds found on the surface are of variable ages with alower germination rate. In the zone on fallow land, the seedsremain on the surface and germinate in the following spring.Ploughing thus has contradictory effects on the seedbanks ofDamasonium: positive because through the opening-up of thehabitat, it favours the appearance of this heliophilous species,and negative because it buries the seeds which progressivelylose their germinating ability.

based on Devictor112

Invasion of the Padulu pool (Corsica) by Dittrichia viscosa

Pozz

o di

Bor

go M

. L.

of spring grazing on the flowering and fruiting of some speciesof temporary pools (Ranunculus sardous, Orchis laxiflora, Agrostispourretii, etc.) have, for example, been observed in Corsica in thePadulu depression291. Such negative impacts are common in theovergrazed areas of the Maghreb. In Morocco, overgrazing leadsnot only to degradation of the plant cover, but is also thought tobe responsible for the disappearance of rare species313. On theother hand, in the north of the Mediterranean, grazing contributesto the maintenance of certain threatened species: this is notablythe case with the Western Spadefoot, a very localised amphibianin southern France, which is closely linked with the action oflivestock, as well as the Parsley Frog and the Natterjack Toad. The

70


germination of Crau Germander (Teucrium aristatum) is also closelylinked to the effects of livestock (Chapter 5d, Box 49).The increase in wild boar populations (Sus scrofa) is accompaniedby increased pressure on habitat, particularly in wetland areas5.Maillard247 was concerned with the Roque-Haute NatureReserve, where the pool sediments are occasionally turned overby wild boar, perhaps seeking Isoetes bulbs (Rhazi, pers. com.).These disturbances, however, create favourable sites for plantgermination and probably play a positive role if their frequencyis not too great. On the other hand, wild boar represent a threatfor amphibians by disturbing their refuges around pools, as hasbeen observed at Valliguières for example240 (Chapter 3f, Box 26).

In Morocco, overgrazing of the dayas constitutes a threat for the flora (Mamora, Morocco)

Gril

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5. Management and restoration methods

a. From site assessment to management plan Perennou C., P. Gauthier & P. Grillas

Site assessment, a prior requirement for any management

What is management?“To manage a natural habitat is to act (or not act) to preserve, orincrease, its natural-heritage value; this may involve the perpetuationof traditional activities, the use of modern techniques or simply themonitoring of natural change, in order to maintain or to modify anecological equilibrium according to specific conservation objec-tives” 331.

Why is management of Mediterranean temporary poolsnecessary?Various human activities and natural processes act directly orindirectly on the pools and may modify their functioning andaffect the species which they support (see Chapter 4). Activemanagement may be necessary to mitigate or correct processesthat have a negative effect on the functioning or the biologicalrichness of the pools. Site restoration becomes necessary whenthe processes of degradation are too advanced.

A framework: the management plan Before taking action (or deciding not to act) at temporary pools,a preliminary phase of discussion and of organising managementactivities is necessary. More and more frequently, this takes theform of a management plan, which is now a well-known tool. Itconsists of:• An approach which aims to set out, jointly, proposals for activ-ities which will be useful in the conservation of the site andwhich are recognised and accepted by all the parties involved:owners, site users, official bodies, organisations.• A document which sets down the results of this approach. Themanagement plan does not consist only of this one document,even if it is formally approved by all the parties involved: if so, itwould most often never be implemented by the local parties, whowould not feel themselves to be involved, whereas its entire pur-pose is to be used for the daily management of the site.

Management plans may take a number of name and formdepending on the context. In France, the Nature Reserves, thelands of the Conservatoire du Littoral or the regional conserva-tories of sites are served by management plans sensu stricto331.The Objectives Documents for the French Natura 2000 sites aremanagement plans in which owners and site users play an impor-tant role397, just as the Water Management and DevelopmentSchemes are the equivalent of management plans for small rivercatchments. The range of titles should not, however, obscure theremarkable consistency of the major logical stages of these mana-gement plans, which corresponds to a sequence of questions (seebelow, this Chapter). More widely in Europe and in the Medi-terranean Basin, the same methodological approach is also fol-lowed or recommended135. Here the concept of the management

plan will be used in a very general sense including, without spe-cific mention, all the various forms which it may take.

Site assessment and management plan Site assessment is always a key phase for establishing initialhypotheses about the possible ecological changes that are takingplace, in order to devise management and monitoring measuresto be undertaken in order to safeguard, rehabilitate or recreate ahabitat.The general approach of management plans is described here asapplied to temporary pools, including the assessment phase.

The stages of the management plan

The structure of a management plan (Tab. 14) corresponds to asequence of questions and answers. Site assessment correspondsto stages 1, 2, 3 and 5. The various stages are detailed below,with the emphasis on aspects specific to temporary pools; moregeneral aspects may be consulted in RNF331.

1. ContextThe area involved should firstly be defined, making the distinc-tion between a central zone, (the pool or stream) and a zone ofinfluence corresponding to the functional space356. This is “the areaclose to the wetland, directly dependent on and having functionallinks with the wetland, within which certain activities may have adirect, strong and rapid influence on the habitat and may seriouslyaffect its continuing survival”.

The zone of influence is defined according to technical criteria:supply from underground or surface water, inputs of pollutants,source zone for sediments, home ranges of mobile species, etc.356

Its dimensions are therefore variable depending on the size, typeand geographical situation of the pool, the factors involved andthe home ranges of the species which it is wished to conserve. Itmay be very large in respect of some parameters. For example,the quality and quantity of water in pools in karstic areas (Valli-guières pool) depends on the groundwater throughout the wholeregion; they may be affected by very distant sources of pollutionor hydrological perturbations.

Box 39. Management plans for temporary pool sites inFrance

The Voluntary Nature Reserve of the Tour du Valat, followed bythe Roque-Haute Nature Reserve, were the first two sites inFrance, rich in temporary pools, to create management plans, inthe 1980s and 1990s respectively. Within the framework of theLIFE “Temporary Pools” project, three sites have also developedtheir own management plans: Notre-Dame de l’Agenouillade,Valliguières and Padulu. The Tre Padule de Suartone havingbeen declared a Nature Reserve in 2000, a management planfor this site should be produced shortly. Finally, a number of sites391 appearing on the list put forwardby France to complete the Natura 2000 network have initiatedtheir Objectives Documents. These documents are in the pro-cess of being drawn up for 19 sites.

Perennou C.

events (fires, etc.) which have taken place there. Examination ofthe land register or archives may reveal details of changes in usesand modes of management at a site through a change of owneror of legal status.

Photographic information: Dated aerial (or land-based) photographsmay give valuable information about changes that have affectedthe site and its zone of influence (catchment area). Aerial photo-graphs are, for example, very useful for studying changes in landuse, the advance or retreat of a woodland or urbanisation. Aerialphotographs are available for the whole of France dating back to1950, in black and white and more recently in colour, for exam-ple from the IGN (www.ign.fr) or the Inventaire Forestier National(www.ifn.fr). Land-based photographs, if their location is preciselyknown, may provide valuable information about the general struc-ture of the vegetation or about land use.

Oral accounts: an inquiry (written or oral questionnaire) amongsite users or nearby residents will provide information about cur-rent perceptions of the site (values) and about past and presentuses. These accounts may for example allow the date of cessa-tion of certain practices (stock rearing, etc.), or the establishmentof others (large-scale agriculture, etc.), to be established. Thistype of information should, however, be treated with caution andchecked against other sources.

Ecological appraisalThis phase entails the defining of initial conditions (or “zero”position) of the site, by:• compiling a list of animal and plant species present at the site(and in some cases also in the zone of influence) ideally by map-ping them (example: Fig. 29),• identifying and describing the key environmental variables invol-ved in the functioning of the site, including the zone of influence,• identifying current and future threats (especially but notexclusively anthropogenic).

3. Site evaluation This evaluation prioritises the importance of the species/habitatspresent at a site by means of reference lists: lists of protectedspecies (at the global, european, national or regional level), RedBooks (at the same levels), Annexes to the Habitat Directives118, etc.Species appearing on the Global Red List (www.redlist.org), or inAnnexe II of the Habitats Directive, are a priori of major interest


What is the general working context1. GENERAL CONTEXT OF THE SITE

What does the site consist of?2. DESCRIPTION AND ANALYSIS OF THE SITE

What is its value?3. EVALUATION OF NATURAL AND SOCIAL HERITAGE

AND OF ECONOMIC VALUES

What future is desired? 4. IDEAL LONG-TERM OBJECTIVES

What are the constraints and assets5. FACTORS INFLUENCING MANAGEMENT

(Positive and negative)

What are the decisions?6. OPERATIONAL OBJECTIVES

How are they to be implemented?7. PROJECTS/PROGRAMMES

OPERATIONS AND TASKS

By what means are they to be commenced? 8. IMPLEMENTATION

WORKING PLANS, ORGANISATION, BUDGET

Is it appropriate/effective?9. MONITORING - EVALUATION

ANNUAL SUMMARY OF TASKS CARRIED OUT AND OBJECTIVES ACHIEVED. REVISION OF THE PLAN

modified from Perennou et al.294

Table 14. The major logical stages of the management plan

Along a stream, the zone of influence may be very long (the wholearea upstream of a given point) and more or less wide dependingon the catchment area. In addition, in the very middle of thestream the upstream-downstream connectivity* is very strong, withredistribution of sediments and of propagules* (eggs, seeds etc.)by the current during floods.

2. The descriptive approach This involves both the examination of existing data and theacquisition of new data.

Collection of existing data Based on searches of the literature and of personal accounts, thispreliminary phase enables the definition not only of current con-ditions but possibly also pre-existing, “reference” conditions.Various sources may be used:

Written records: Some sites have been the subject of researchwork or assessments that have given rise to publications, some ofwhich may be old (for example the Grammont pool, Hérault, France).Unpublished data (reports, student dissertations, accounts offield trips, etc.) may also be very rich in detailed information andmay be sought from universities and scientific societies. Newspaperarticles may provide information concerning the site, its uses, or

Marsilea strigosa, a flagship species of temporary pools (annexes I of theBerne Convention, II and IV of the Habitats Directive)

72

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Figure 29. Example of the presentation of information on the natural-heritage value of a site (extract from the management plan forNotre-Dame de l’Agenouillade, Fuselier152)

Residential area

Residential area

Chemin de Notre-Dame à Saint-Martin

Impa

sse

des

Prun

ette

s

Carpark

0 10 20 40 m

100 m2

Site boundary Site entrances

Mediterranean temporary pools*

Mediterranean swards with Brachypodium retusum**

EU Habitats Directive habitats

Damasonium polyspernumLythrum tribacteatum

Natural heritage flora

Bufo calamita*Hyla meridionalis*Triturus marmoratus*Triturus helveticus*Myotis myotis**

Natural heritage fauna

Copses with Elm dominantMixed copses: Buckthorn, Azerole, Ash, Elm, TamariskGiant ReedDry calcicole swards Mediterranean humid grasslands Pond vegetation communityAbandoned farmlandPlant communities of ruderal areas

Vegetation types

Former military buildingsRuinsUrbanised areasFormer mini golf courseMain pathsWellsRestaurant “Le Lapin de Baluffe”Water purification stationRoads

Physical planning

Fly tipInvasive species Senecio inaequidensPools colonised by woody speciesPools colonised by tall helophytes

Main threats

Former vineyards

Grazing General Presentation of the Notre-Dame de l’Agenouillade Life Site

Mapping 2001: J. Fuselier (ADENA)Field surveys: 2001 (J. Fuselier) – 2000 (O. Houles)*eggs, larvae and juveniles ** indices of major presence for these species

*Priority habitat – Natura 2000 Code: 3170 - ** Remarkable habitat

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compared with a species that is rare or protected simply at thelocal level (example, Tab. 15). The evaluation will also be able todraw on the expertise of recognised specialists, particularly forgroups that are poorly represented on the lists (insects and crus-taceans for example).

For example, at the Roque-Haute Nature Reserve (Tab. 15), twospecies of plants, as well as the “Mediterranean Temporary Pools”habitat (Annexe I Priority of the Habitats Directive), are of Euro-pean importance. Thirteen species are of national interest (nationalprotection and/or Red Data Book), with 16 additional species pro-posed for Volume 2 of the Red Data Book. A further 12 species areof regional interest. It should be noted that there are no lists foruse in evaluating the interest of habitats at a national or regionallevel.The identification of Habitat 3170 in France may be facilitated bythe use of the Habitat Registers158 which give details of the sub-categories of each habitat, their characteristic suites of plants(enabling them to be identified), and their ecological require-ments (see also Box 8, Chapter 2a).

4. Directions (or long-term objectives)The presence of the “Mediterranean Temporary Pools” habitat, andof species with high natural heritage status, will often justifyincluding their conservation in the long-term objectives of themanagement plan. More generally, the conservation or restorationof optimal hydrological and/or ecological regimes at a site willgenerally determine the directions of management. Examination ofthe assets and constraints associated with the site is necessarybefore long-term management objectives can be defined.

5. Factors which may influence management (assets andconstraints) and their indicators The descriptive phase (cf. § 2. above) has allowed the factors to beidentified, within or outside the site, that have or may have aneffect on its functioning or its natural heritage value. The presentstage has the aim of drawing up a systematic list of these factors andof evaluating the magnitude (current or potential) of their effects.

The potential causes of dysfunction at a pool are very numerousand it is not possible to list them all (see Chapter 4). However, a

REGIONALBer HD Pr RDB

I. HABITATS Mediterranean temporary pools (code 3170)

Ann. I Prior.

II. SPECIES Adonis annua T 2Aristolochia clusii xBufonia tenuifolia T 2Bupleurum semicompositum xChenopodium urbicum T 2Crassula vaillanti T 2 xDamasonium polyspermum x• Elatine macropoda T 2 xGagea granatelli x• Heliotropium supinum xIsoëtes duriaei x T 2Isoëtes setacea x VKickxia commutata x T 2Lotus conimbricensis T 2 xLythrum borysthenicum xLythrum thymifolia x V• Lythrum tribracteatum x VMarsilea strigosa x x x VMentha cervina VMyosotis sicula xNonea echioides T 2Ophioglossum azoricum x VOrobanche laevis T 2Picris pauciflora T 2Pilularia minuta x x VPolygonum romanum ssp. gallicum T 2 x• Pulicaria sicula T 2 xPulicaria vulgaris x T 2Ranunculus lateriflorus x VRanunculus ophioglossifolius x T 2Romulea columnae xRomulea ramiflora T 2Taeniatherum caput-medusae T 2Tamarix africana x T 2• Trifolium ornithopodioides xValerianella microcarpa T 2Velezia rigida T 2Veronica acinifolia T 2

EUROPEAN NATIONAL

Table 15. Plants of natural-heritage value present in the Roque-Haute Nature Reserve

Green: protected temporary-poolspecies Other species: protected species ofhabitats other than temporary pools • species formerly included but whosecurrent presence is considered to bedoubtful

Status:Ber = Berne ConventionHD = Habitats Directive

National:Pr = Officially protected status x = protectedRDB = National Red Data Book T 2: candidate species for volume 2 ofthe Red data BookV = Vulnerable

Regional: Officially protected statusx = protected

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systematic evaluation of the significance of the most commondisruptive factors is necessary. This may be carried out by use ofimpact indicators which assess the status of populations and com-munities, and indicators of the functioning of the physical environ-ment which will often provide information regarding the causesand mechanisms of the dysfunction.

Impact indicators Dysfunction of a temporary pool may be suspected when:• the population size of one or a number of species (animal orplant) is decreasing,• communities or characteristic species are disappearing and/orbeing replaced by others (spread of tall helophytes* and trees,increase in algae, etc.),• species typical of different ecological conditions coexist withthe characteristic temporary-pool species.

The hypothesis of dysfunction may derive from a historical studywhich establishes that conditions have changed over time, and/or from a comparison with similar habitats (richness in species orin groups of species, abundance of particular species, etc.). It isimperative that this analysis takes into account normal populationfluctuations, especially those resulting from weather conditions.Interpretation of the data will be facilitated by use of references:previous data from the same site and under the same climaticconditions, or observations from other relevant sites (fluctua-tions are not necessarily synchronous between sites). Comparisonbetween the current conditions and old data must be carried outwith caution and must take into account any possible differencesin methods and objectives.

The decline of one species may be linked not only with the dis-appearance of its habitat but also with other factors such as theappearance of a new predator or problems of reproduction (seedor egg predation, infertility, inbreeding, etc.), which do not neces-sarily have any connection with the habitat. The assessment of aspecies may therefore lead to more thorough studies of its biology.

When dysfunction has been confirmed or seems probable, itscauses must be investigated. Hypotheses, generally many at first,are generated. In the case of a temporary pool, disruptions of the“classic” key factors involved in its functioning are looked for:hydrological regime, water quality (eutrophication or pollution),sedimentation, closing-up of the habitat (cf. Chapter 4).

Functional indicators The number of potential indicators is very high when the widerange of causes of the degradation of ecosystems are considered.While some indicators are applicable to many cases (water levelfor example), the search for indicators that are best suited to alocal situation will take place through a functional analysis ori-entated towards the most probable causes of ecological change.For example, the hydrological regime may suddenly be disruptedby human activities (drainage, siltation of a pool, continuous arti-ficial supply of water, etc.): the ecological changes will then beimmediate and the causes easy to establish visually. When thehydrological modifications are less severe, such as reduction orprolongation of the flooding period (due to pumping, climaticchange, modifications in the zone of influence, etc.) it will onlybe possible to reveal them through long-term monitoring.The effect of an input of nutrients (eutrophication) will be identi-fied by measurements of nutrients (cause), or of dissolved oxygen,

pH or primary production (effects), or by indicator species: forexample the proliferation of certain species of algae or of helo-phytes to the detriment of plants typical of oligotrophic* condi-tions, or the disappearance of animal species which are sensitiveto the oxygen content of the water (certain insects, etc.).

Inputs of toxic substances (herbicides, insecticides or accidentalpollution) will often be more difficult to establish. Even though somespecies (bryophytes* and invertebrates for example) are recognisedas being accumulators of some substances, their quantificationremains difficult. When the hypothesis of toxic pollution is beingconsidered, it is vital to consult experts to obtain verification.

Sedimentation and erosion are natural processes, whose ratevaries in relation to the type of substrate, the slope and the con-dition of the vegetation (Chapter 4). The rate of sedimentationmay increase when the vegetation cover in the catchment areadecreases (clearing, fire, erosion due to human activity, etc.). Thehydrological regime and the animal and plant communities willbe progressively affected. More competitive, less water-demandingplants will become established. Monitoring the depth of the waterand/or the depth of the sediment may help with the diagnosis.Organic sedimentation is often less significant than the mineralcomponent due to the low productivity of the pools which resultsfrom their nutrient*-poor status and from limiting hydrologicalconditions. However, this organic element may become predomi-nant when inputs of litter from the catchment area are large orwhen productive species establish themselves in the pool (woodyplants, helophytes) (see Chapters 4 and 5c).

In summer, the use of the Chevanu pool (southern Corsica) as a car park causescompaction and ruts which are visible during the flooded phase

Pozz

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.-L.

(OEC

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Usage indicators Changes of use bring with them modifications of the ecosystemswhich affect the physical environment as well as the populations(Chapter 4). These changes of use need to be identified usingsimple indicators such as, for example:• cessation of grazing (indicated by closing-up of the habitat,indicator species, the characteristic shapes of browsed shrubs,low walls, etc.),• cultivation of pools or their surroundings (ploughing, lowwalls, drains, etc.),• digging (extraction of material, shape of the pool, slopes, etc.),• dumping of various materials,• use for parking (soil compaction, destruction of vegetation,ruts, etc.).

6. Operational objectivesThe operational objectives of the management of Mediterraneantemporary pools will be the site-specific application of the direc-tions (§ 4 above), once the constraints and assets have beentaken into account (§ 5). Some objectives will be centred on bio-diversity conservation issues (particular species or communities,physical characteristics, etc.), others on activities and uses at thepool or in the surrounding area (grazing, crop growing, forest,built-up areas, etc.), and still others on the integration of the sitewithin the social sphere. For example, the Valliguières161 manage-ment plan sets out, among others, the following objectives:• to augment the size and viability of the Great Crested Newtpopulation by improving its breeding success and its adult survival,• to improve the potential of the site as reptile habitat,• to involve the local commune and its residents in activitiesrelated to the management and understanding of the site.

7/8. Operations A very wide range of management operations can be imple-mented, in response to the diversity of ecosystems and of threats.These may involve, for example, simple surveillance of the condi-tion of key ecological characteristics of the site (notably hydrology),detailed ecological management or even restoration of the pools,actions affecting the catchment area, awareness raising amongsite users, environmental education, specific activities involvinga species, and/or the acquisition of the site or setting up a man-agement contract. Two particular examples are given here:

• The restoration of pools The highest priority of the management objectives will be to con-trol or correct unfavourable ecological changes. The operationswill consist of eliminating the causes of degradation (siltation orpollution, for example) and then re-establishing favourable con-ditions for the characteristic Mediterranean temporary-poolspecies. Actions involving the water, the soil, the vegetation, andthe provision of information to site users will often be required,and they will be accompanied, if necessary, by the re-introduc-tion or reinforcement of populations of the species.

• CreationThis involves, in this case, the construction of a functioning sitewhere none currently exists. The creation of a Mediterraneantemporary pool requires a thorough initial study of the ecologi-cal functioning of the site33, 215, 411, 419. It is essential that some ofthe physical characteristics (substrate, hydrology, etc.) are suit-able, while others increase the chances of success of the habitatcreation (proximity of other temporary pools, etc.) (“Assets andconstraints” paragraph, this Chapter).

Studying the seed bank (core sampling of the sediment),a tool in the restoration feasibility study (Péguière pool,Var, France)

Gril

las

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Outside a management plan: brief or detailed assessment?

In some cases a site assessment is necessary without beingincluded, at least in the first stage, in a management plan (forexample, appraisal in the framework of contractual managementsuch as Natura 2000). This assessment may be more or less thoroughdepending on the particular case.Brief assessment, based on ecological inventories, enables anypossible dysfunction to be identified with the aid of comparisons(bibliographies or reference sites), and hypotheses regarding theircauses to be generated. This rapid assessment corresponds tophases 1 to 3 and 5 of the management plan. The individual car-rying it out must have a thorough understanding of the ecologyof this type of ecosystem (temporary pools or streams), and prefer-ably of the site itself. External experts may be consulted regardingtopics requiring more highly specialised knowledge, relating tospecies (for example the identification of certain groups, popula-tion biology) or to complex processes (hydrology, hydrogeology,etc.). As well as this basic knowledge, an expert will be familiarwith examples with which comparisons may be made, allowingdysfunctions to be identified.Detailed assessment furthers the analysis by focusing it on theresults of the brief assessment. It is the combination of “Initialassessment” + “Detailed assessment” that generates the hypotheseswhich form the basis for decisions regarding management mea-sures and monitoring (see Chapter 6 and Tomas-Vives388). Detailedassessment is in general undertaken in the two following cases:• validation (or refutation) of the hypotheses formulated regardingthe previously identified ecological changes,• evaluation of the resilience of the ecosystem, i.e. its capacityto return to normal functioning when the cause(s) of the dys-function have been corrected. The study will seek to examine forexample the possibilities for the restoration of populations in theabsence of direct intervention (introduction, population rein-forcement).

Most successful assessments, leading to effective managementmeasures and to appropriate monitoring, are based from the out-set on accurate recording of the species present and of environ-mental factors.

Box 40. A brief assessment: the Rodié pool (Plaine desMaures, Var)

It was at this flagship pool in the Plaine des Maures that theRodié Buttercup (Ranunculus revelieri subsp rodiei) was discov-ered and described for the first time. At present, rapid assess-ment based on the distribution of the vegetation leads to thehypothesis that rushes (Juncus conglomeratus) are invading thepool. The rapid assessment does not permit the verification ofthis hypothesis of ecological change. A likely cause is the alter-ation of the hydrological regime following widening of the roadwhich has encroached upon the site.

In order to test the hypothesis and to evaluate the possibleimpact of the spread of rushes on the Rodié Buttercup it was

decided to survey the site. This involves a number of aspects: Detailed mapping of the rushes and the vegetation was carriedout at the time of maximum water level.The area occupied by the Rodié Buttercup and by other plantspecies is regularly surveyed using fixed quadrat transects.In addition, the buttercup is accurately counted in each quadrat.The surface water level (hydrological monitoring) is regularlyrecorded from a fixed scale in the centre of the pool. The exis-tence of a detailed topographic study, previously carried out,allows the duration of flooding at different parts of the pool tobe deduced from this water level at a single fixed point.


Box 41. A detailed assessment: the Péguière pool (Plainedes Maures, Var)

The Péguière pool site was well known until only about tenyears ago for its flora, characteristic of a low-elevationIsoetion formation (Médail, pers. com.), with species such asRanunculus revelieri. At present there are a number of indica-tions of infilling:• no open water phase (surface water),• very deep soil,• vegetation typical of temporary pools no longer appearsexcept in a fragmented way, in small depressions.

Botanical surveys (quadrat transects) currently reveal a com-monplace grassland flora with Paspalum dilatatum, Antho-xanthum odoratum, Festuca gr. ovina, Holcus lanatus, Avenabarbata, etc. A study of the topography and the hydrologicalregime has shown that water levels are determined by thegroundwater, which follows the (non-horizontal) profile of theunderlying rocky substrate.

The probable cause of the infilling of the pool is strong erosionwithin its catchment area, which is exacerbated by the degra-dation of the vegetation by fire and the repeated passage andparking of vehicles (cars, motorcycles). Now that the catch-ment area has been protected from vehicle traffic the vegeta-tion should rapidly recolonise and the rate of erosion shouldslow down. Restoration (dredging) of the pool may thereforebe envisaged.

Since the current vegetation (zero state) is very poor, it seemedadvisable to evaluate the potential of the seedbank for restor-ing the former floristic richness of the site. Regular core sam-pling of the soil was therefore carried out over the wholesurface of the pool. These core samples were then divided intofour depth layers (each 2.5 cm) to locate any viable seedstocks. Germination tests on the soil samples revealed low levelsof seeds for the species being looked for (the Isoetion).The restoration of the flora of the site cannot therefore bebased on its own seedbank. It will have to rely on spontaneousrecolonisation from nearby sites (the network of rivulets in thecatchment area) or on reintroduction of seed.


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b. Land management and usesPerennou C.

In most of the countries of the Mediterranean Basin, the State orregional authorities are able to restrict the uses to which privateland is put, within the framework of statutory protective mea-sures. However, it is not possible to compel an owner to managethe land for nature protection who does not wish to do so. Hence,the control of land uses by public or private nature protectionbodies may be essential for the management of temporary pools.Such control may be either complete (through acquisition) orpartial (by contract, lease, or agreement with the owner). Acqui-sition, or even partial control over the land, is not a preconditionwhich needs to be applied in every case. Less restrictive and lesscostly means will be preferable whenever they are possible.

The incidence of resorting to acquisition or contractual manage-ment for the conservation of natural habitats is very variabledepending on region and country. In some there are private orpublic organisations with their own resources and with experi-ence in these methods of control. However, in many countriesexperience is non-existent or only recently acquired. In addition,information is very scattered and little published, and almost neverspecifically relates to Mediterranean temporary pools. Summariesare rare, with the exception of those carried out in the Medi-terranean countries of the EU within the framework of the LIFE“Green Register” for coastal habitats44 (www.green-register.org).The following is therefore based mainly on information relatingto a wider range of natural habitats (Natura 2000 sites, coastalsector, etc.). This information is, however, very likely to be rele-vant to the pools. Outside the EU information is practically non-existent, and it appears to be practically impossible to implementactions to influence land and use management, particularly if, asis very often the case, the landowner is unknown. Superimposed tra-ditional rights and nationalisations/denationalisations may create alegal tangle which is difficult to unravel (Bougeant, pers. com.).

Within the EU, the European Commission deems the acquisitionof land of high biological value within the framework of LIFE pro-jects to be acceptable only to the extent that it enables activemanagement, necessary for the protection of key species or habi-tats, to be carried out. For areas of land considered to be alreadyprotected through their inclusion in the Natura 2000 network,acquisition through LIFE cannot be seen as a means of counter-ing threats, which in this situation are the sole responsibility ofthe member States. Temporary pools constitute a habitat wellsuited to the philosophy of Natura 2000, which advocates thatmanagement be carried out by contract as much as possible:these habitats have for a long time depended on traditionalhuman activities which are currently in decline (stock grazing);their restoration often takes place through the maintenance orrestoration of these activities, by agreement with those whocarry them out or by adapting them (DFCI, for example) toimprove their compatibility with conservation.

Land acquisition Acquisition is the mode of control offering the greatest long-term security. It may be achieved by a public organisation: • in France: Conservatoire du Littoral, départements,• in Portugal, following the purchase by the State of the landforming the current Paul de Boquilobo Nature Reserve in the 1970s,the Istituto de Conservaçao da Natureza has recently begun toacquire land within the protected areas which it manages,• in Spain, the government of the Balearic Autonomous Commu-nity (8000 ha acquired) has a wide experience of acquiring landfor nature,• in Italy, no public authority has acquired land for conservationto date, but some regions are beginning to take an interest,• in Greece, the State is acquiring land in the Central Zones of theNational Parks20 but information is lacking as to the areas acquiredup to now. The same procedure is envisaged there within theframework of Natura 200020 and, more widely, for natural coastalareas close to tourist zones44.

Acquisition may also be achieved by a private interest:• foundations: Fondation Sansouire in France (many temporarypools in the Camargue), Fundacio Territori i Paisatge in Cata-lonia (FUNDTIP; 7000 ha acquired in 2 years of activity), Fon-dation Global Nature in Spain (www.fundacionglobalnature.org/),etc.• organisations: WWF Italy (many “oases”), Conservatoire Régio-nal des Sitesa in France, GOB and SEO/BirdLIFE in Spain (540 habought by the SEO in the Belchite steppes and the Ebro Delta, withinthe framework of European ACNAT/ LIFE projects) (www.seo.org),Nature Protection League in Portugal (purchase of land of ornitho-logical value in the south of the country, Castro Verde, within theframework of two LIFE projects), etc. In most references it is not stated whether or not the acquiredland contains temporary pools.As organisations that are more administratively flexible, but whichoften have access to fewer funds compared with public bodies,they are more vulnerable to the financial hazards of a project:delays in payments by providers of funding, greater difficulty inobtaining loans.

Acquisition is facilitated when specific organisations exist for whichit is one of the main aims, if not the only aim: specific resourcesallocated, financial skills and contacts, legal arrangements facili-tating their involvement (pre-emptive right, price-regulatingbodiesb, possibility of compulsory purchase, inalienability of theacquired land, etc.). Spanish regions have often abandoned pro-jects due to their administrative complexities.

Inalienability provides one of the best guarantees for the protec-tion of sites in the very long term: once acquired, there is no riskof resale. This is the norm in France for Conservatoire du Littoralland and in Spain for that belonging to FUNDTIP.

Compulsory purchase is an expensive method (legal procedures)to be used selectively and useful mainly as a tool in negotiations.The right of compulsory purchase exists in all the MediterraneanEU countries but to different degrees: strong and widely used inFrance, weak in Italy and Spain, limited to a narrow coastal stripin Portugal, and not used for conservation purposes in Greece.

The study carried out within the framework of the GreenRegister44 concluded that the principal legal tools permitting the

a. Depending on the region, these may be either association-based or dependenton the local authority.b. Such as the Service des Domaines in France, the Comisiones Provinciales deUrbanismo in Spain, and similar bodies in Italy and Portugal.

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acquisition of land are well established in the Mediterraneancountries of the EU but little used for conservation purposes.

Acquisition may appear expensive in absolute terms: in the con-text of the LIFE “Temporary pools” project, approximately 2500 to4000 €/ha have been set aside for purchases carried out in 2002-2004 in southern France. However, the balance sheet for acqui-sitions in France by the Conservatoire du Littoral shows that thetotal amounts are small in comparison with investments in otherspheres44.

Use management by contract/agreement

These methods allow the use of the land to be partly regulatedwithout acquisition and hence at lower cost. They may also beused, if the manager is also the owner, to delegate a proportionof the management activities (in particular grazing).

Contracts and agreements may be very variable in type and dura-tion even within a single country (see Lévy-Bruhl & Coquillard234 forFrance, for example). The ease with which they may be imple-mented for the conservation of natural habitats is probably variablefrom country to country, but no summary exists. These modes ofmanagement fall within the framework of an increasing tendency

to encourage private owners to feel responsible, (see for examplePietx298) and are especially suited to the “Natura 2000 philoso-phy”. It should also be noted that at a given site they may be usedin a complementary way alongside land acquisition, as has beenthe case at a number of LIFE sites (Fig. 30), in the regulation of thecatchment areas as well as of the pools themselves.

In France, the Conservatoires Régionaux d’Espaces Naturels reg-ularly employ this mode of site regulation. They currently manageover 35,000 ha of natural habitats through contracts with hun-dreds of farmers and communes131.

In Slovenia, a LIFE Nature project in the Karst Edge (Kraski rob),situated in the sub-Mediterranean part of the country, providesfor the restoration of four pools followed by their managementbased on contracts with the official managers/owners, with theaim of conserving their biological value (Sovinç & Lipej, pers.com.).

In Spain, since 1999, about twenty NGOs (mainly in Catalonia andthe Balearics) have set up activities of this type on behalf of nat-ural habitats, and a guide to these practices has been publishedin Catalan (Pietx, pers. com.). The Fondation Global Nature, forexample, has created, by means of agreements with the owners,a network of 49 private Biological Reserves, amounting to almost

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■ Land parcels acquired by the CEN-LR within the frame-work of the Life “Mediterranean Temporary Pools” project

■ Land parcels subject to a land management agreementbetween the CEN-LR and the commune of Valliguières(and the ONF for land parcel 70)

■ Land parcels subject to a land management agreementbetween the CEN-LR and an individual

■ Temporary pools

■ Perimeter of Natura 2000 area

■ Catchment area of the wetland

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Figure 30. Land evaluation of the Etang de Valliguières Natura 2000 site

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4000 ha, for the protection of the Spur-thighed Tortoise Testudograeca in Andalusia and in the Murcia Region (www.funda-cionglobalnature.org/). Such networks could also be created forother species or habitats such as temporary pools. SEO/BirdLIFE(www.seo.org) manages eight reserves (over 1000 ha), mainlycomprising ornithologically valuable habitats, by agreement withprivate or municipal owners. In the Guadalquivir Delta, a privateestate which forms an enclave within the Doñana National Park(the “Finca de los Gonzalez-Byass”) contains some temporarypools. Its management is subject to management guidelines fromthe National Park, by agreement with the owners (Serrano, pers.com.).

The Autonomous Community of Valencia has created an innova-tive system of “floristic micro-reserves”217, which is a hybrid sys-tem of contractualisation and strong, compensation-based legalprotection. A micro-reserve (always <20 ha) depends on the volun-tary acceptance of management constraints as prescribed in acontract agreed with the regional authorities. It may only berevoked by the owner if the compensation received is repaid withinterest. The owner receives compensation in one single paymentof up to 1800 €/ha in the case of wetlands (maximum of 6010 €/site for private or municipal owners, 18,030 €/site in the case ofan NGO, Foundation or University). An extra premium of 50%may be paid if the sites contain plants which are strictly pro-tected by the Habitats Directive. In early 2003, of the 150 micro-reserves created in this way in Valencia, three have temporarypools (Tab. 16). In view of its success, this formula has also beenproposed for use in the Castilla-La Mancha and Andalusiaregions (Reques, pers. com.).

In Andalusia, a similar mixed system (contractual-statutory) wasset up by the Law 2/89 of 18 July 1989. It provides the possibil-ity of creating “Partnership” Nature Reserves for sites with highnatural value, in particular on private land. It does not yet appearto have been used to protect temporary pools. In 2002, the Spanishgovernment opened a credit line enabling such contracts to beagreed for the management of Natura 2000 sites (Pietx, pers.com.).

In Portugal, cases are very rare. An agri-environmental contract(not yet approved) has been proposed for one site with tempo-rary pools (Alcazar, pers. com.). In the Vale do Guadiana NaturalPark, contracts have been agreed between the Park’s managementbody (ICN) and some landowners in respect of measures to supportthe birdlife. Such measures have not been considered necessaryfor the conservation of the temporary pools in the Park due to

their small area, easily excluded from cultivation (Cardoso, com.pers.).

In Morocco, the Sidi Bou Ghaba Ramsar site contains a fringe oftemporary marshes. Classified as a forestry estate, it is, in thiscapacity, the property of the State and is managed by the Ministryof Agriculture, Rural Development, Water and Forestry. The Societyfor the Protection of Animals and Nature (SPANA), a MoroccanNGO directed to the public benefit, has been managing the wholesite for several years on the basis of an agreement with the Depart-ment. SPANA carries out surveys and conservation of the floraand fauna, deals with visitors and manages the education centre.This management is carried out in collaboration with all the par-ties involved in the conservation of the environment within theframework of a local committee (Bouchafra, pers. com.). Thisexample of contractual land management by a conservation NGOis remarkable, and may be the only case among the countries ofthe southern Mediterranean.

Summary of these methods of regulation

In Greece, land acquisition and leasing contracts for the protec-tion of habitats still do not take place (Dimitriou, pers. com.)except in the central zones of National Parks.In Portugal, these modes of involvement are still very little used(Alcazar, pers. com.) despite some recent achievements by NGOsand State bodies (ICN). In Spain, acquisitions have especially involved sites of ornitho-logical value (and hence not temporary pools a priori); there areseveral cases of part-contractual, part-statutory management atthe micro-reserves of Valencia.In France, a range of temporary pools are at least partly underland management, both by the State (Conservatoire du Littoral)and by NGOs: Valliguières, Redon, Plaine des Maures, pools atLanau, the Tour du Valat and Vendres, etc. In total, more than2000 ha of land where pools occur are protected in this way. Inaddition, management agreements have been set up with ownersor managers at two sites at least (as at 1/10/2003), in theframework of the LIFE “Temporary Pools” project. Complementarycontractual measures are likely to be put forward within theframework of the implementation of Natura 2000 contracts atfurther important temporary pool sites.In Turkey, these modes of protection/management of land do notappear to be used, either by the State or by NGOs (Bulus, com.pers.), while in Morocco an experiment in management by agree-ment, albeit not involving pools, is in progress.

Table 16. Micro-reserves in Valencia containing temporary pools

Lavajo de Arriba Sinarcas Council

0.5 ha

Lavajo de Abajo idem 0.7 ha

10.5 ha(ca. 3 ha of wetland, 7.5 ha ofCork Oak forest and matorral)

Micro-reserve Owner Area

Balsa de la Dehesa Soneja Council

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c. Management of habitats andspecies Gauthier P. & P. Grillas

Introduction

The management/restoration or creation of temporary pools mustbe preceded by a detailed site assessment (Chapter 5a). This pre-condition allows potentially deleterious activities to be minimised.Sometimes, in the absence of information enabling hypothesesregarding the changes taking place to be confirmed, decisionsmay be based purely on these hypotheses. An understanding ofsimilar situations and sites is therefore essential. In all cases anevaluation of management is necessary (Chapter 6), in order pos-sibly to question the hypotheses and/or to adapt managementactivities (“Adaptive management”).

Whether the project relates to management/conservation,restoration or creation of a temporary pool, it is crucial that anunstable hydrological regime is maintained (or restored/created);the irregularity is a key factor in the functioning of this habitatand of its species.

Before any restoration activity takes place, it is necessary:• to ensure that the causes of observed negative changes havebeen removed (or may easily be removed),• to evaluate the feasibility, the cost in terms of man-hours, thefinancial costs and the probability of success,• to assess the impact of the operations on the functioning ofthe ecosystem as a whole: operations aiming to favour one speciesor a group of species may be unfavourable to others or detrimen-tal to some human activities (costs and benefits of the operation),• to evaluate the extent of the operation: when natural hydro-logical conditions have been re-established, should the speciesbe allowed to recolonise the site naturally? Or should all or partof the range of species whose return is desired be re-establishedartificially?419

Box 42. Land acquisition: the lessons of the LIFE“Temporary Pools” project for France

The management of land or usage is often very time-consum-ing, all the stages listed below being potentially subject todelays, as the LIFE “Temporary Pools” project has shown:• identification and location of landowners, not always possi-ble within the project deadlines,• preliminary contacts with landowners who are not very con-servation-minded,• negotiations, sometimes complicated due to land being in jointownership, the reversals of landowners, rapid changes in thelocal property market,• various administrative delays: deliberations of the publicbuyer, obtaining bank loans, etc

In the context of the LIFE “Temporary Pools” project, delays ofthree or four years between the initial contact (project set-upphase) and the signing of the purchase agreement have beenexperienced. Interruptions of the process at the conclusion ofthe phases of location of, and initial contact with, the owner,also occur for various reasons:• change of mind on the part of the owner (or of one or moreowners in the case of joint ownership) so that they no longerwish to sell or lease their land,• sale to another private purchaser (via a faster decision) orthe acceptance of a higher purchase price.

In the framework of a short-term project (4-5 years) of theLIFE type, some pernicious effects may be seen towards theend of the projects. The sellers increase their selling priceknowing that the purchasers have little available time beforethey forfeit their LIFE funding. If the asking price rises abovethe limit acceptable to the providers of the funds, anticipatedpurchases will have to be abandoned.

In total, of five sites initially earmarked for acquisition, onlytwo were purchased, as well as a third which was not initiallyidentified but where an opportunity arose. Furthemore, at oneof these sites, a proportion of the purchases have beenreplaced by management agreements judged to be adequate inview of the management issues.

Perennou C.

Box 43. General recommendations for the restoration ofwetlands

Zedler419 sets out ten basic principles for the restoration ofwetlands:• The location of the site is decisive: the conditions regardinggeology, water etc. must be favourable.• Natural sites must be used for comparison.• The hydrological regime (instability in the case of temporarypools and streams) is a crucial factor in the restoration of thebiodiversity and functioning of a wetland.• The various components of the ecosystem (nutrients*, organicmaterial, sedimentation, vegetation, fauna, etc.) develop atdifferent rates.• The accumulation of nutrients (P, N) in the sediments mayslow the rate at which biodiversity redevelops.• Some types of perturbation (felling, grazing etc.) may aug-ment species richness.• The existence of a seedbank and/or of dispersal processesmay facilitate the restoration of a diverse plant cover.• The environmental conditions and the biological characteris-tics of the species must be considered when the restoration ofthe biodiversity of a site is desired. It may be pointless to rein-troduce species which will colonise naturally when the eco-logical conditions become favourable267, while Nature must behelped in the case of some sensitive species or when naturalrepopulation is improbable402 (absence of a seedbank or sourcepopulation).• Predicting the restoration of a wetland depends on the theoryof succession, the vegetation at a given site being in a state ofcontinuous change.• The existence of genetic differences within a species (eco-types) may influence the results of a restoration project: theintroduction of populations which are poorly adapted to theecological conditions at a site may end in failure (disappearance,etc.).

Based on Zedler419

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When manipulation of species proves necessary, a number ofproblems may arise408: • legal: manipulation of protected species is subject to legislation,• technical: for most species, techniques for captive breeding (orbreeding in vivo) and reintroduction into the wild are poorlydeveloped,• genetic: the source populations for reintroduction will generallyhave to be from nearby sites, to minimise genetic contaminationand to benefit from local adaptations. There will still, however,remain a risk of genetic bottlenecks* (low genetic diversity linkedwith low numbers).

The principal habitat management operations at tempo-rary wetlands

The choice of management operations is determined in the firstplace in relation to their appropriateness regarding the existingproblem and the processes at work (Tab. 17). For each of theseoperations, evaluations of the technical feasibility and of thecosts involved are very important factors to be taken intoaccount before operations can begin.

Management operations carried out at LIFE “Temporary Pools”sites and at other temporary pool sites are described here by wayof example. They should only be applied to other situations if thewhole process, starting with an appraisal of the initial conditionsand the management problems, is carried out from start to finish.Information which is incomplete or partly empirical does not per-mit the formulation of more general models for management orrestoration. The implementation of a management operation isabove all a local decision that depends on the available informa-tion (literature, surveys, comparisons etc.), on the characteristicsof the site and on the available resources.

Sedimentation management Infilling forms part of the natural dynamics of pools but may beincreased by various perturbations (Chapter 4, Box 44). It resultsfrom the accumulation of minerals derived from the catchmentarea and of organic material produced on the site or brought infrom outside. The consequences of sedimentation are an increasein the depth of the sediment and its water content (and hence adecrease in the level of water stress in summer and heightenedcompetitiveness of perennials), a decrease in the depth and duration

Box 44. Management of a temporary pool followingburning: the example of the Catchéou pool (Var)

During the summer of 2003, the Massif and Plaine des Maures wereseverely affected by fire, with 1960 ha burnt. The areas of the mas-sif with cupular pools, and the parts of the plain with depressionsand temporary streams, fell within the area of devastation. In the Plaine de Palayson, the famous Catchéou pool was burnt, aswell as several temporary streams. Following the disappearance ofthe vegetation cover, it was feared that increased sedimentationand severe eutrophication would take place, due to the erosion ofthe catchment area (sand-rich substrate). Fire therefore consti-tutes a double threat, acting directly on populations (amphibians,reptiles, etc.) which cannot escape it, and indirectly through ter-restrialisation which may modify the hydrological regime of thepool and so indirectly disrupt its animal and plant communities(decrease in the duration of flooding). Burial of seedlings alsoposes the risk of germination failure for some plants. Given the very high natural heritage value of the site, the OfficeNational des Forêts decided on preventative intervention.Ecological engineering operations have therefore been carriedout by the ONF, in partnership with the CEEP. These actions,based on the techniques of the Restauration des Terrains enMontagne (Restoration of Mountainous Land) type, are tailoredto the problem and to the size of the pool, with a view to min-imising erosion and the deposition of sediment.

The management works consisted of:• placing fascines in semicircles in two rows all around the pool.These fascines are made from branches of Tree Heath Erica arborea(unburnt), reinforced beneath by Giant Reed Arundo donax to givegreater rigidity. Posts of 10-cm diameter ensure that these fascinesare firmly fixed, and their bases are slightly buried in the ground. Thepurpose of the fascines is to limit the silting up of the pool by mate-rial brought down from the catchment area, in particular during theautumn rains, which are generally heavy. They should also limit the

amount of ash being washed into the depression. They act as filtersand allow water to pass through,• in the thalwegs of the catchment area, burnt scrub was cutout and the dead material removed,• the felling and removal of dead burnt trees within a radius of50 m around the pool.

Site monitoring is planned, including:• hydrological functioning (dates of flooding and drying, waterlevels),• measurement of the rate of sedimentation using graduated scales inserted into the bed of the pool,• monitoring the fauna (invertebrates and amphibians),• monitoring the flora,• photographic monitoring.

Catard A. & L. Marsol

After a fire, the protection of the Catchéou pool with fascines slowsdown the silting-up process (before the fire, see photo page 10)

Mar

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Problems Process Objective Management method Remarks (faisability, etc.) Cost

Infilling Accumulation of sediment • reduction in hydroperiod

• burying of seeds

Restore a favourable hydrological regime

Replace the seeds on the surface in conditions favourable to germination

Digging: manual if small surface area (spade); mechanical if larger surface area (digger)

Prior determination of the depth of digging required, depending on previous regime, seedbanks, etc.

Depends on how far the sediments are removed from the site

Restoration of the plant cover in the catchment area, limitation of frequentation

Accumulation of litter of internal or peripheral origin leading to:• burying of seeds

• eutrophication

Remove litter

Reduce internal or peripheral sources

Limit accumulation

Superficial removal (manual)

Control of woody species and large helophytes

Delicate operation: high risk of removing seed stocks with the litter and of damage to the existing vegetation

Low if surface area is small

Direct modification of the hydrological regime

Drainage Restore a favourable hydrological regime

Sealing of drains, filling in

Permanent filling with water by direct supply (pipe, etc.)


Removal of the water supply

Indirect modification of the hydrological regime (interventions in the catchment area)

Diversion of runoff water, plantations on catchment area, removal of water from the water table


Restoration of the catchment area, legislation controlling removal of water from the water table

Very variable Very variable

Permanent filling with water through modification of the catchment area (dam…) or supply from the water table

Competition/Light, Eutrophication

Shrub encroachment Open up the habitat, limit intake of organic matter

Scrub clearing or cutting, with removal from the site of cut vegetation, grazing

Increase in large helophytes Limit competition

Limit intake of organic matter

Cutting and/or root stripping, with removal of cut and uprooted vegetation,

Grazing

The cause of the increase should be identified: Modification of the hydrological regime? Absence of grazing?

Root stripping runs a high risk of removing seed stocks from the site with the root mat and of damage to the existing vegetation

Increase in the density of small terrestrial or amphibious herbaceous plants

Limit competition Vegetation clearing with removal of the cleared vegetation, Grazing

Invasive plant species Limit competition Limit accumulation of organic matter

Arrachage manuel, pâturageInformation, communication

The durability of action to limit invasion should be evaluated

Predation Introduction of fauna (fish, crayfish, etc.)

Remove the predator Elimination of fish fauna / return to an unstable hydrology Information, communication

Elimination of crayfish and certain invasive amphibians is not very likely as they have refuges outside the pools

Pollution Direct dumping Awareness raising, reduce risks Information, communication with public and local authorities, government departments responsible for enforcing anti-pollution law

Indirect dumping (in catchment area)

Limit sources of pollution Information, communication, contracts, etc.

Debris, dump Cleaning Information, communication, etc.

Overgrazing, excessive trampling

Modification in the structure of the substrate, acceleration of erosive processes Deterioration in the plant cover Limitation of reproduction

Reduce the amount of grazing, modify grazing seasons, etc.

Information, communication, contracts, etc.

Colonisation of the catchment area by woody plants

Disturbance of amphibians in the terrestrial phase

Open up the habitat Scrub clearing or cutting, with removal of cut vegetation, Grazing

Scrub clearing should be limited in order not to increase erosion and to maintain refuge areas, with potential shelters for amphibians

Table 17. Choice of management operations according to their appropriateness with regard to the existing problem and the processes in place

84


Box 45. An example of restoration by digging: thePéguière pool, Var, France

Siltation of the pool was diagnosed, caused by increased erosionin the catchment area, whose vegetation had been degraded bythe passage of vehicles (Box 41, Chapter 5a). Acquisition by theConservatoire du Littoral and management by the commune(Cannet-des-Maures) have enabled the traffic to be controlled:the vegetation should recover rapidly and the erosion shouldslow down. The assessment also concluded that it would be pos-sible to restore the hydrological regime of the pool by digging,and there were no significant residual seed stocks capable ofrestoring the populations of temporary pool plants.

A restoration project has therefore been devised, to proceed inseveral stages: • Assessing the water regime at the pool.• Carrying out the digging works.• Verifying the re-establishment of favourable hydrological con-ditions (possibly involving corrective works).• Monitoring the possible appearance of the desired species.• When the hydrological conditions are re-established and if thespecies do not colonise the habitat spontaneously, introductionby means of seed stocks derived from the closest sites (nearbystreams).

A plan has been drawn up for taking off a top layer of sedimentfrom the eastern part of the pool and removing it from the site(Fig. 31). The thickness to be removed was determined in such away as to lower the surface of the soil down to the water table,as measured in May 2001, and to retain a thin layer of soil abovethe underlying rock. It was decided to carry out the removal closeto the inlet point of a rivulet so as to facilitate filling with water,and over a limited proportion of the pool so as to reduce thecosts of removing the sediment from the site and to verifywhether the hydrological objectives are achieved (submersion forsome weeks every year, at least during wet years). It will be pos-sible to carry out corrective works if necessary. Since it is notnecessary to retain any soil horizon to reseed the site, theremoved sediments will be taken away, but will be dumped fairlyclose by so as to minimise transport costs. The gradients definedare shallow, so as to avoid erosion and to promote a wider rangeof conditions. The proposed area to be modified amounts to 530 m2 and the vol-ume of sediment to be removed will be 115 m3. The cost of theoperation is estimated as 3300 € of which about one-third is forthe digging and the remainder for transporting the arisings.It is planned to carry out the works during the first few weeks of2004.

Grillas P., N. Yavercovski, E. Duborper & M. Pichaud

Map

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Figure 31. Restoration of the Péguières pool

(1) Relative elevation in m of the initial state (2) Relative altitude in m after silt removal

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85


of flooding (and hence terrestrialisation), the burying of theseedbank and the impossibility of germination for species withsmall, light-demanding seeds. It ends most commonly in replace-ment by commonplace plant and animal communities (with lossof specialised species and of the animals which only complete apart of their life cycle here). Management enables the accumulation of mineral and organicsediments to be limited, when its causes are well understood. Thedegradation of the vegetation in the catchment area is a classiccause of accelerating erosion of the catchment area and, as aresult, of sedimentation in the wetlands downstream. The causesof this degradation may be brought under control through mana-gement (control of grazing, human pressure, vehicle tracks, etc.).At the minimum, a barrier of vegetation may be constructedaround the edge to catch the sediment while allowing water topass through.

When the siltation is associated with an accumulation of mineralsoil, correct hydrological functioning may be restored by diggingout the pool and taking away the sediment. Depending on thesize of the pool, this digging may be mechanical or manual. Themain difficulties with restoration by removal of the upper layerof sediment are, firstly, deciding on the level to be dug down to(historical level or level to be calculated based on hydrologicalobjectives), and secondly, the presence or otherwise of viableseed stocks. The digging must therefore be complemented by acartographic study of the underlying substrate and an analysis ofthe various soil horizons, so as to locate any seed stocks and ifpossible to use them for restoring the vegetation.

Management of woody vegetation The colonisation by woody vegetation around and within tempo-rary pools brings problems of shading (competition) and litteraccumulation, and, as a result, difficulties for heliophilous*species as regards emergence and growth (Chapter 4). Openingup the habitat reduces light competition and the input of litter.Depending on the extent of the area to be cleared, cutting maybe done manually (using shears) or mechanically (power saw,brushcutter). The maintenance of the cleared area must then beensured, preferably using livestock, which will control both thewoody species and also the most competitive herbaceous plants.Various livestock may be used, depending on the characteristicsof the species which it is wished to control. For example goats,and to a lesser degree sheep, will be more effective than cattleor horses for controlling woody growth.

Management by grazing should be subject to an agreement withthe owner of the stock, in which may be included periods whenno grazing takes place (sensitivity of some species at critical stagesin their development), and the maximum grazing pressures perhectare (threshold for the risk of overgrazing). The effect of graz-ing may be measured for particular target species or, overall, forthe richness or structure of communities or of the ecosystem.

Management of helophytes The spread of large helophytes (rushes, Scirpus, bulrushes etc.) intemporary pools may be linked to various causes such as anincrease in the depth of the sediment, or an increase and/or stabil-isation of the water level. These highly competitive species developto the detriment of the characteristic temporary-pool species,which struggle to survive in their shade and in the increasinglyeutrophic conditions resulting from the accumulation of their litter.

The management of helophytes (rushes, Scirpus, etc.) thereforeaims, as for woody plants, to reduce the amount of shading andthe inputs of litter.In the case of helophytes, mechanical cutting (brushcutter) fol-lowed by removal of the cut material, may be accompanied bystripping*, a technique which involves stripping off the root mat,to thoroughly remove the plants (equivalent to stump extractionin woody plants) and to facilitate the reappearance of light-demanding species (heliophiles). This second management oper-ation must be fairly precise, and hence it is often carried outmanually, to avoid removing any underlying seedbank whichcould possibly have survived beneath the helophytes. The main-tenance of the cut areas should be carried out manually or by theuse of controlled grazing.

Box 46. Spread of woody plants in the pools at Roque-Haute

In the pools at the Roque-Haute Nature Reserve (Hérault)where no grazing has taken place for about fifty years, thespread of elm (Ulmus minor) and ash (Fraxinus angustifoliasubsp oxycarpa) appears to be unfavourable to populations ofIsoetes setacea328. This hypothesis was tested by means of anexperimental clearing operation. One year after the woodygrowth was cut, the frequency of Isoetes had increased by 43%in the cleared zone compared with an increase of just 7% inthe non-cleared zone (a “year” effect). In addition, in thecleared zone, a decline in litter caused the frequency of Isoetesto increase by a further 14%. A complementary experiment, inthe laboratory, showed that reduction in light affects thebiomass production and the production of spores in thisspecies (Fig. 32). These results therefore suggest that intercep-tion of light by the woody species, or more generally by com-petitive species, is sufficient to explain the reduction in thesmall species characteristic of Mediterranean temporary pools.Other effects may also be involved, in particular those associ-ated with the decomposition of organic material or modifica-tion of the soils, but they have not been tested for.

Rhazi M.

Figure 32. Impact of light on the production of biomass andspores in Isoetes setacea

0.180.160.140.120.100.080.060.040.020.00

0 15 50 75

Mea

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Light reduction (%)

86


Box 47. An example of management by removal of vegetation:Lac des Aurèdes (Var, France)

The artificial reservoir of Les Aurèdes, situated in the middle ofthe Escarcets Estate, owned by the Conservatoire du Littoral, wasconstructed in the 1960s and 1970s for use in fire defences. Itsbanks are subject to temporary flooding and support manyspecies belonging to the Isoetion. In the absence of grazing,these areas are at present partly invaded by helophytes*: rushes(Juncus conglomeratus) and Scirpus (Scirpus holoscheonus).As part of the LIFE “Temporary Pools” project, experimental man-agement by vegetation removal (simulated grazing) was under-taken in two areas, one dominated by rushes and the other byScirpus, to assess the detrimental effect of these helophytes onthe Isoetion assemblage.In these two areas, three homogenous sections (replicates) weremarked out. Each section was then divided into two, a controlzone and a treatment zone. In the areas with rushes and withScirpus, the three control zones received no treatment and thethree treatment zones were cleared every autumn, with removalof the cut material.In the area with rushes, in autumn 2001, stripping* was alsotested in part of each treatment zone.In all zones the vegetation was studied using the quadrat tran-sect method, in 2001 before any intervention (zero state), in2002 and in 2003.

Opening up the habitat had an effect on:• the total species richness, which increased from 66 species in2001 to 105 in 2002 and then 77 in 2003,• the number of characteristic temporary-pool species (Fig. 33).

In the area with rushes, this number changed very little in thecontrol zones. In the treatment zones, it increased from 3 (in2001) to 8 (in 2002) and then 7 (in 2003). At the same time, inthe stripped zone, it increased from zero to 4 and then 3.For the Scirpus areas, in the control zones it tripled between2001 and 2002 (from 2 to 6 species), and then fell again to 3 in2003. At the same time, in the treatment zones it increased from2 to 12 and then 6.The effect of opening up the habitat was very positive in 2002and a little less in 2003. However, the appearance of species ofthe Isoetion does not always correspond to the restoration of thisplant formation. This only appears in its entirety on soils that areshallow (<15 cm) or even skeletal. If the soil is deeper than 20 cm,

the soil water content allows large helophytes to grow, whichcompete with the Isoetion species; this was the case in the areasselected for vegetation removal. The appearance and mainte-nance of the Isoetion outside its optimal habitat thereforerequires not only drastic control of the emergent vegetation butalso favourable climatic conditions as was the case in 2002(whereas there was a late flooding in 2003).Following the stripping, Isoetion species are thus colonising thehabitat, but at relatively low density, possibly due to the disap-pearance of the seedbank below the root mat.

Félisiak D., E. Duborper & N. Yavercovski

Figure 33. Impact of the opening-up of the habitat on the number of characteristic species of pools

Experimental management of the Petites Aurèdes site (Plaine des Maures)by rush cutting

Roch

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Control zones

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9876543210

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Management of the herbaceous vegetation cover Some small species of high natural-heritage value may be verysensitive to competition from the herbaceous vegetation. Theywill be favoured if this vegetation is kept closely cut and sparse,and by micro-perturbations connected for example with theaction of wild or domestic animals.

Creation The creation of a temporary pool first of all involves the creationof a depression which will hold water during the wet season.Once the depression has been created, there are several possiblemethods of establishing species, in particular plant species: • It is generally preferable to allow natural colonisation fromnearby sources to take place by itself267. The proximity of func-tioning temporary wetlands, “potential reservoirs”, improves thechances of natural colonisation of artificial sites by specialisedanimal or plant species. It also increases the probability of theexistence of suitable physical characteristics (substrate type,porosity, filtration, presence of groundwater, weather conditions,

etc.), which should be verified before undertaking any habitatcreation works.• If spontaneous colonisation is impossible (absence of suffi-ciently close sites) or too slow, the re-introduction of animaland/or plant species may be considered. The organisms shouldcome from the closest possible sites to minimise genetic con-tamination and to maximise the chances of success (growingconditions similar to those at the source sites). They should be insufficient numbers to minimise the risk of genetic bottlenecks* inthe populations.For plant species, the reintroduction will preferably be effectedin the form of seeds, or of soil containing a diverse seedbank62, 403.The introduction of seeds should take place before the autumnalflooding to maximise the chances of germination. Soil conditionswill need to be suitable for the germination of seeds and thegrowth of seedlings. In addition, competition from more vigorousspecies should be controlled. In the early stages, protectionagainst herbivores will assist with the initial development of thepopulations.

Box 48. Scirpus-Isoetes competition at Roque-HauteIn order to test the hypothesis that Isoetes setacea communitieshave been locally replaced by Sea Club-rush (Scirpus maritimus)communities in the pools at Roque-Haute, an assessment of theseed stocks was carried out. If Scirpus has recently replacedIsoetes, the densities of Isoetes spores, which are not very mobile,should not be significantly different between the two types ofcommunities. Sediment samples (0-3 cm) were taken, at severalpools, from areas dominated by Scirpus and Isoetes respectively.The density of Isoetes spores in the samples was evaluated by thegermination method (from April to October).

The densities of Isoetes spores were as high within Scirpus areasas they were in Isoetes areas (10-15 spores per 100 g of soil, ata depth of between 0 and 3 cm, Fig. 34). The recent developmentof Scirpus was confirmed; it is probably linked to changes in theuses of the temporary pools, and in particular the cessation ofextensive sheep grazing. Ageing of the pools could also beaccompanied by nutrient* enrichment, facilitating dominance byScirpus. Management that simulates grazing (close and regularcutting of Scirpus) or the resumption of sheep grazing shouldstimulate the Isoetes community by reducing the competitiveadvantage of Scirpus.

Grillas P.

Figure 34. Density of Isoetes spores under Scirpus and Isoetesformations

■ Under Isoetes■ Under Scirpus

0-3 cm 3-6 cm

Den

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Box 49. Grazing and the conservation of Teucrium aristatumpopulationsThe Lanau pool, in the Crau (Bouches-du-Rhône) is the onlyremaining site in France for Teucrium aristatum, Lamiaceae285.Small, scattered populations are distributed within the outer beltof vegetation around the pool, in small bare depressions that areperiodically flooded. The herbaceous vegetation has become talland dense since the cessation of grazing in recent years. For this species, which is apparently very sensitive to competitionfrom other herb species, extensive grazing appears to be a neces-sary condition for the maintenance of sizeable populations, oreven for its survival. To test this hypothesis, part of the pool wasreturned to grazing and the numbers of the Germander werecounted over three years in the two zones (grazed and ungrazed).A very significant increase in the population was observed in thegrazed zone (Fig. 35). In the ungrazed zone, a single plant wasfound in 2003 to be growing in a bare area that was no doubtcreated by the activities of rabbits. Not only does grazing limit thedensity of the dominant vegetation cover, thereby reducing com-petition, but in addition trampling tends to create micro-depres-sions suitable for the germination of the Germander. The initialhypothesis appears to be confirmed and the area of the pool sub-jected to grazing should be extended, with continued monitoring.

Yavercovski N., J. Boutin & E. Duborper

88


Figure 35. Dynamics of Teucrium aristatum in the Lanau pool

Grazed zone Ungrazed zone

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Management of populations of rare speciesby grazing at the Lanau pool (France): grazedpart on the left, exclosure on the right

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Box 50. Reintroduction, reinforcing populations

Reinforcement constitutes an important method for the mainte-nance of populations whose numbers are not sufficient to guar-antee the survival of the species.These projects should be carefully controlled and carried out withgreat care if long-term success is to be guaranteed. There is anIUCN reintroductions “charter” which lists the operations to befollowed394.In contrast with what has been achieved with other groups ofvertebrates (birds, mammals), there are very few cases of amphi-bian reintroductions in Europe12, 91.On the other hand, operations to move populations have beencarried out in several countries, for example France232, Spain332

and Italy354, 355. These translocations are carried out when natu-ral habitats must be destroyed (e.g. for development) or whenthey cannot be restored, or when the risk of extinction of thespecies necessitates an increase in the number of populations. This method is appropriate when the decline is not associatedwith unresolved environmental issues.The results of these operations depend on several factors, includingthe number of individuals moved and the characteristics of thereception site. In the case of pool creation, decisions as to whichtype of aquatic habitat to provide must be based on a study ofthe environmental characteristics of the site, the presence of otherwetlands nearby and an understanding of the particular require-ments of the “target” species.

The case of the Great Crested Newt Triturus cristatusSeveral translocations affecting Great Crested Newt populationshave been carried out in Great Britain88, 89, 226, 257. Of 178 opera-tions carried out, 37% were successful, 10% failed, and in morethan 40% of cases the absence of long-term monitoring pre-vented any assessment. The probability of failure is high whether the translocationinvolves adults, larvae or eggs. Each stage has its own advan-tages and disadvantages which should be taken into accountduring a translocation. Moving adults poses two problems: fidelity to the original site(return to the site if the distance and the ground conditions per-mit) and poor adaptation to the new site (notably absence offamiliarity with the terrestrial habitat). Movement of larvae would appear to be preferable as they havenot yet developed the sensory capabilities required for orienta-tion during their terrestrial phase: they will be capable of orien-tating normally during their migration. The disadvantage of usinglarval stages is the low survival rate during the immature phase.Translocation failure may be due to the poor quality of the recep-tor site. Some simple recommendations for evaluating the qualityof this site are given in table 18.In southern France (Valliguières), a conservation project is cur-rently being carried out with a population of Great Crested Newtsby the Conservatoire des Espaces Naturels du Languedoc-Roussillon(CEN-LR). The excavation of an artificial pool close to the sourcepool is being planned from both the experimental and the oper-ational point of view. This operation should allow breeding totake place more regularly and a second breeding site to be createdwhich is designed to increase the population’s size and chancesof survival (Box 26).

Lombardini K.

1. Absence of other amphibian species in the pool Especially the Palmate Newt which has similar habitatrequirements.A site that is rich in amphibians constitutes a favourablefactor unless there are competitor species (Marsh Frog, etc.).

2. Presence of fish and crayfish in the pool Fish and crayfish are predators of larvae and adults. Theirpresence may be disastrous for newts.

3. Visits by herons to the pool Herons are predators of larvae and adults. Their presencemay be disastrous for newts.

4. Terrestrial habitat too restricted or degraded The terrestrial habitat close to the pool may support 250adult Great Crested Newts per hectare.However, the absence of certain factors (hedges, woods,etc.) may be detrimental to this species.

5. Unsuitable aquatic habitat An absence of aquatic plants, needed for egg laying and theproduction of invertebrates, may be unfavourable for thesurvival of some amphibian populations. Herbaceous vege-tation may allow amphibians to hide and escape frompredators such as herons, etc.

6. Presence of a “barrier” in the terrestrial environment The presence of a swiftly flowing river, a major road or bareground (arable land etc.) less than 100 m from the pool maybe dangerous for “exploring” newts.

7. Public access The public may introduce fish or other undesirable speciesinto the pool. Remote or inaccessible sites are preferable.

8. Presence of Great Crested Newts in the pool Adding a colony of newts to a pool which already supportsthem is almost never beneficial in conservation terms.

9. Absence of trees Tree cover can be unfavourable to predatory birds.

Table 18. Selection criteria for Great Crested Newt sites – Negative indicators

90

6. Monitoring

a. Why and how to conductmonitoringPerennou C.

Monitoring in its broadest sense consists of the regular and stan-dardised collection of data: the same parameters, usually col-lected at regular intervals, using the same method throughout.The term covers two different scenarios, the choice of which willdepend on the objectives of the manager:

• Surveillance, the aim of which is simply to find out the varia-tion in time of the quantity being measured (the number of stalksof Marsilea in a pool, the number of breeding newts, the arrivalor the expansion of an invasive species, the water levels or theeutrophication of a pool, etc.). The simplest and often the cheap-est form of monitoring to implement, it is also the most widespreadamong managers. However, it has its limitations, which are notalways fully considered, the main one being that it does not gen-erally allow the causes of the phenomena observed to be identi-fied after the event. Nonetheless, preliminary surveillance doesenable changes to be measured and as a result, a monitoring pro-gramme to be commenced if necessary. Before carrying out mea-surements in the field, selection of the best and most appropriatemethods and indicatorsa for the assessment of the situation (bio-logical, socio-economic, etc.) is essential.

• Monitoring (in the strict sense) has more ambitious objectives:to identify the causes of the variations detected (for example,“What has caused the decline of the Great Crested Newt on mysite?”) or to verify that a parameter deemed essential remainswithin acceptable limits or develops in the desired direction. Thismonitoring could accompany a management operation to verifythat it is having the desired results (recovery of numbers forexample). The results of the monitoring enable the managementof a site to be adapted if necessary. In this sense, monitoring is avital tool for the adaptive management of habitats. If managerswish to discover the causes of a phenomenon of interest to them,to gauge the response of the habitat to a management operation,etc., the putting in place of genuine monitoring often requiresthe measurement of additional parameters to those of simplesurveillance of the phenomenon. A framework for drawing upsuch a programme is set out in the MedWet Monitoring Manual(Tomas Vives388 downloadable on www.wetlands.org/pubs&/wetland_pub.html#MW5).

To summarise (Tab. 19), a monitoring programme can be drawnup145 step by step, the main points of which are as follows:- The prior precise identification of the problem/question to tackleis essential: a formulation that is too vague will prevent thedevelopment of a rigorous monitoring programme.

- The precise objective of the monitoring should be formulated.This formulation cannot be limited to “Monitoring the populationof such-and-such a species” or “Monitoring the intensity of such-and-such a phenomenon”; it could, however, be “To verify ifpumping from the groundwater reduces the water supply to thetemporary pool through springs” or “To verify that scrub clearingaround the pool helps Isoetes to reappear in larger numbers”.

- It is essential to formulate a hypothesis regarding the expecteddevelopment of the phenomenon being monitored; this enablesmonitoring in the strict sense to be distinguished from surveil-lance for which the trends of the parameters being monitored arenot identified at the start.

- A monitoring programme can only respond to the precise ques-tion for which it was created. Its results will not generally beappropriate for responding to any other question, even one thatis ostensibly similar.

The outcome of a monitoring programme is an operation or achoice of management (stage 10) relating to the problem raised atthe onset (stage 1). For a site manager, merely increasing knowledge,without any resulting implications for management, does notgenerally justify the implementation of monitoring programmeswhich are costly both in time and financially.

Thus, a monitoring programme in the strict sense is similar to sci-entific experimentation in the rigour of its formulation and itsapproach based on hypothesis and deduction. Henceforth in thischapter, the word “monitoring”, unless otherwise stated, will referto both surveillance and monitoring in the strict sense as describedabove.

Collection and analysis of data The choice of monitoring methods should be made by consider-ing not only the objectives of the monitoring but also the meth-ods of data analysis and the costs. A pilot study is stronglyrecommended in order to evaluate the whole of the protocol so

a. It is essential to distinguish carefully between the indicator and the phenomenonof interest to the manager. For example, eutrophication is a complex pheno-menon, which can be assessed through indicators of the type “Concentration in thewater of nitrates or phosphates”; but eutrophification does not consist solely ofthese parameters.

Table 19. MedWet framework for monitoring

1. Identify the problem/question �

2. Define the objective�

3. Establish the hypothesis�

4. Choose the method and the variables�

5. Evaluate the feasibility and the costs �

6. Pilot study�

7. Collection of data (fieldwork, etc.)�

8. Analysis of data�

9. Interpretation and communication of results�

10. Management operation and evaluation

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6. Monitoring

as not to invest too much in a monitoring programme. Manymonitoring methods can be used and it is not possible, within thecontext of this management guide, to carry out a systematicreview. Before beginning a monitoring programme, it is preferableto consult specialist works, especially with regard to methods ofmeasurement and data analysis73, 129, 142, 346, and/or consult a spe-cialist. The type of sampling, the permanence or otherwise of therecording stations, other aspects of data collection (season, fre-quency, etc.) and the methods of analysis of subsequent datashould be chosen in close collaboration with a specialist in thefield concerned. Otherwise, there is a risk that it will be impossibleto subject the data collected to a rigorous interpretation (insuf-ficient frequency, unsuitable period, etc.) or that fieldwork will beunnecessarily heavy (time wasted in carrying out more measure-ments than are required for the question posed, for example).

Certain physical and biological characteristics of Mediterraneantemporary pools, as well as their interannual dynamics, must betaken into account in the choice of methods and protocols. Someexamples below illustrate the distinctive features of temporarypools, and methods suitable for these habitats are described inthe following chapters (6b to f).The great temporal and spatial variability in the abundance ofspecies poses practical problems for the siting of recording posi-tions and the frequency of readings. This irregularity increases

the interannual variance of the variable (abundance, for example)and increases the difficulty of detection of ecological variationsor the effects of a change in management which will onlybecome apparent after a few years.Cupular pools are sometimes so small that their surface area doesnot allow a sufficient number of samples to be placed to conformto statistical requirements. The possibility of using small-sizedsamples, thanks to the very small size of the plants, sometimeshelps to resolve this problem by increasing the number of samples.The physical properties of the habitat, and therefore the vegeta-tion and many animal species, are organised in gradients alongthe topographic gradient. Depending on the objective of the vege-tation monitoring, the distribution of the measurement pointsmay be regular over the whole of the pool, spaced out over thevarious belts, or linear, parallel to the main gradient, in order toevaluate the change in distribution of the species through time.

It must be stressed that the more ambitious the objective of themonitoring, the more costly it will be, notably in terms of timefor the collection of data. It is therefore often preferable for themanager to start from the resources available (“How much timecan my team devote to monitoring each year?”) and to define arealistic objective with this constraint in mind, rather than fixingan objective which calls for resources that are not available, withthe result that the work is only half completed.

Figure 36. Water cycle

Ocean

Precipitations

Snow and ice

Ground water

Salt water

Water tableRun off

TranspirationEvaporation

Cloud formationRain and snow clouds

Atmospheric circulation

Solar radiation

Evaporation

Rivers and lakes

92


b. Hydrological monitoring Chauvelon P. & P. Heurteaux

The establishment of a quantitative assessment of the hydrologicalfunctioning of a water body requires the censusing of the com-ponents of the water cycle (Fig. 36) involved in this functioning.An adequate knowledge of the geographical and geological charac-teristics of the habitat studied, plus a minimum of measuringequipment (metrological capacity), are essential.

The geographic and geological characteristics to be ascertainedhave already been mentioned in Chapter 3b.They are obtained through the thorough study of all the docu-ments which can be assembled regarding the extended environ-ment of the site studied: topographical maps, geological maps,pedological maps, aerial views (photos and/or satellite images).These data enable the crest lines defining the catchment area tobe detailed, its surface area to be calculated, its topography andits vegetation to be assessed, its lithology to be understood(stable rocks, porous rocks, karstic networks) and the possibleinvolvement of the underground water in the surface water cycleto be assessed. This information will facilitate the inventory andthe description of modifications to the catchment area likely tohave an influence on flows (ditches, drains, etc.)

Additional information will often be necessary: topographicalsurveys to clarify the map contours and produce a detailedbathymetry of the water bodies (Box 51), characterisation of thesedimentary substrate (texture, structure, stratification) both atthe bottom of the pool and in the surrounding area to a depth atleast equivalent to the level of the bottom of the pool.

Metrological capability relates primarily to monitoring water levelsin the pool and quantifying rainfall, evaporation from open waterand evapotranspiration. Bear in mind that hydrometric equip-ment installed in a public place is open to the risk of theft orvandalism.

Measurement of levels (Box 52) should be carried out regularly.Automatic continuous readings are obviously the best solution.Though there may be no other option but occasional measure-ments, two measurements per month would seem to be a mini-mum. If possible, the measurements of rainfall events should bemade at the latest one or two days after they have finished. It isbest not to be tied to fixed dates, as there is little chance thatthe dates of the visits will coincide with interesting hydrologicalevents.

To quantify rainfall, the data from existing observation networksis usually used (Box 53), despite the considerable spatial variabilityof rainfall, especially in the Mediterranean region where rain-storms predominate. When the density of pluviometers is insuffi-cient, and for a precise reading, measurement on the site, i.e.within a kilometre and at the same altitude, will be necessary.

Estimates of water losses to the atmosphere (evaporation andevapotranspiration) are usually made by calculation from clima-tological data, using empirical formulae. All require at least theair temperature in the shade and other more elaborate ones, suchas that of Penman293 require, in addition, the air humidity, solarradiation and/or the duration of sunshine, and the wind speed.

Box 51. Topography and bathymetry

The bathymetry of the pools studied can be obtained fairlyeasily by a comparative method in relation to the calm surfaceof the water body, at a period of maximum water level of thepool. All that is needed for this is a tape measure, a depthgauge and some good waders.It is advisable to have at least two markers fixed to the ground,aligned along the major axis of the pool: one in a “central”position and the other on the edge or on the bank. Theseclearly visible markers (bench marks, solidly fixed pegs) willserve as a reference for the geometric description of the siteand monitorings. As a basis for description, we suggest thenmeasuring the depths across four to eight transects regularlyspaced along a reference axis formed by the two bench markson the ground. The density of transects in the pool and thenumber of measurement points per transect vary greatlyaccording to the topography: they will be low on regular gra-dients and increase when the gradients are irregular.

For monitoring that combines accuracy, quantity of data andeconomy of time, professional topographic equipment isneeded. With an electronic theodolite or tacheometer withlaser rangefinder and two operators, several hundred readingscan be acquired per day with one centimetre accuracy, andstored in the memory for direct informatic use.Once the reference station has been set up, bi-frequency dif-ferential GPS allow readings with one centimetre accuracy tobe taken by just one operator on the ground, who can move ina radius of several kilometres around the reference site to takethe point readings.These measurement devices are costly, but both types can behired (around 1000 € per week for a differential GPS, and dailyhiring is also possible). Basic training is required on how to usethem, provided by the hire company.When budgets are limited, but personnel are available andtime is not limited, it is possible, for the price of a week’srental, to purchase geometer optical equipment which can beused time and time again.

Chauvelon P. & P. Heurteaux

Few managers will have the chance to measure these parametersthemselves with the aid of an automatic meteorological stationon their site. The data can be provided by organisations manag-ing measurement networks. In France, these data can beobtained from Météo-France, and the INRA – at a price - andpossibly from the agriculture (DDA) or equipment (DDE) servicesof the French départements. The actual evapotranspiration (ETR) of a plant cover is not calcu-lable from field data and the method commonly used consists inusing a reference climatic value: the potential climatic evapo-transpiration (ETP). According to the water content of the sub-strate, the ETR of a plant cover will represent a certain proportionof the ETP.

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6. Monitoring

Relative proportions of sources of waterIt is difficult to quantify how much water in a pool is supplied bythe run-off from its catchment area or by underground water.When investigation proves possible (loose rock, sands, silts, nottoo pebbly), it is useful to survey the underground hydrodynamicsby installing and using a network of piezometers (Box 54). On fissured bedrock or a very pebbly formation, “light” prospecting(hand auger) is not possible. In the hope of improving under-standing of pool-groundwater interactions, one could in this casejust locate the wells and springs likely to exist on the catchmentarea, and compare the change in the levels and the electricalconductivity of water* in these wells and springs with those of thepool. This approach implies topographic survers which are oftendifficult to ascertain.

Box 52. The measurement of surface water levels A water level gauge can be purchased commercially (in enamellediron) or made by hand. In principle, the zero of the scale shouldcorrespond to the deepest point of the pool. The water levelshould be capable of being read from the bank (with or with-out binoculars).The installation of a water level gauge at the deepest point ofthe pool can pose logistical and/or aesthetic problems if thevariations in water level are significant. If the configuration ofthe pool allows it, an oblique gauge can be placed leaningagainst a bank, in which case the angle of inclination must betaken into account to correct the reading.In all cases, an installation which is easily visible and accessi-ble runs the risk of vandalism. If the risks or technical difficul-ties make the placing of a water level gauge impossible, one ormore discreet and stable markers can be installed in the poolafter their spot height has been measured in relation to thedeepest point of the pool. The depth of the water is then mea-sured by placing a pole vertically against the marker.This is a simple and fairly cheap method of recording the waterlevels at regular time intervals. However, in the case of siteswhich are difficult to access or lack personnel, it does notenable information to be obtained corresponding to the criti-cal phases of sudden variations in the levels. Whenever this ispossible, the use of recording devices is preferred.

A limnigraph is a device which records the variations in waterlevel continuously. There are several models in existence(mechanical or electronic float limnigraphs; pressure sensors).Their price often makes them unaffordable, especially as theyrun the same risks as the water level gauge.

Chauvelon P. & P. Heurteaux

At Valliguières, the influence of karstic wateron the pool has been established throughpiezometric monitoring

Roch

é J.

94


Box 53. Measurement of rainfall

Pluviometers are open-top receptacles which capture the rainthat falls on their surface. In theory, nothing could be simpler,but in fact the intermittent nature of rainfall, the turbulencecreated by wind and the apparatus itself affect the representa-tiveness of the measurement when extrapolated to a whole site.The size of the receiving surface, on the other hand, only has alimited influence on the percentage of rain collected321. Ideally, itis better to distribute several small gauges over a site than useone single large one.There are several types of cummulative pluviometers. For all ofthese, it is important that the measurement is taken shortly aftera rainfall event. In France the most commonly used model is the“Association” pluviometer (“Association Scientifique de France”).This consists of a bucket surmounted by a funnel, the opening ofwhich is a rigid ring of 400 cm2 chamfered on the outside. Theinstrument is placed on a support. It is made of zinc or plastic.The measurement of the rainfall is made in a collecting tubegraduated in millimetres and tenths of millimetres of rain. A mil-limetre of rain corresponds to one litre per m2.The pluviometer should be positioned according to standardisedconditions: receiving surface horizontal, between 1 m and 1.5 mabove the ground. To avoid interference from nearby obstacles(trees, buildings, etc.) it should be set apart at a distance of atleast three times the height of the nearest obstacle. Pluviometersinstalled in places open to the public have very little chance ofsurvival. In this case, it is best to look around in the neighbour-hood of the site to locate “private” pluviometers, or look for anaccommodating landowner who is willing to host the apparatusand take readings. In all cases, data should be obtained from thenearest meteorological station, bearing in mind that there isoften a charge made for data.

There are self recording rain gauges (tipping bucket rain gauges,float type raingauges) which record continuous rainfall events.Storage raingauge also store rainwater. These instruments arepractical on sites with difficult access or when there are notenough personnel for daily collection of the data. It is even pos-sible to make a storage raingauge oneself (Fig. 37). Simply soldera nozzle to the base of the funnel of a “Association” pluviometeror any other receptacle (large food container, catering size,whose receiving surface is measured, and into which whitecement is poured in a slanting form to channel the flow, to pre-vent splashing and act as ballast) and using a flexible plastictube, link it to an opaque flask placed in a carefully insulatedcase (buried if possible). The opacity prevents the growth ofalgae. The receiving surface is supported by a hollow metal tube(central-heating type) into which the plastic tube passes, protected

from the light. If readings occur at very irregular intervals, somedrops of paraffin oil and formalin in the flask prevent evapora-tion and the putrefaction of organic debris (bird droppings).Gloss paint facilitates the slide of raindrops and protects againstcorrosion. The volume of rainwater collected is measured in acollecting tube or by weighing the tared flask (to the nearestgram or tenth of a gram, if possible). As the area of the receivingsurface of the pluviometer is known, the volume measured canbe converted into the rain depth. Thus, with a pluviometer of400 cm2 and a 10-litre flask, up to 250 mm of rainwater can bestored. The rain depths measured should be rounded up to thenearest millimetre.To minimise soiling, it is sometimes necessary to equip the recep-tacle with a perch for birds (small metal rod).


Figure 37. A home-made cumulative pluviometer

Perch

Whitecement

for slope Food container

Box - insulated orburied

Air inlet

Flask

Soil

The volume of the storage

receptacledepends on the

receiving surface

Receptacle

Rigid support ø 1” ou 3/4”

Flexible plastic tube,ø 8-10 mm

Pier

re H

eurt

eaux

95

6. Monitoring

Box 54. Measurement of underground water levels usingpiezometers: simple methods of implementation

• What is a piezometer? A piezometer is a device for looking at groundwater. It consistsof a pipe installed in the ground which goes down into thegroundwater, theoretically as far as its impermeable substrate. A filter allows underground water to enter the tube as far as thegroundwater level, the variations in which can then be measured.The water can also be extracted for analysis.

• What information can piezometers provide and how can thisbe obtained?To have an overview of the dynamics of the groundwater and itspossible connection with a water body, several piezometers mustbe installed. Their minimum number and spatial dispersal dependon the configuration of the terrain, and specialist advice isdesirable at this point. The ease of the work, the security of theinstallations and the time that can be devoted to monitoringshould also taken into account. The transect method is usuallyrecommended for evaluation of the position of the groundwaterand its gradient. For example, along a specified axis, a line ofpiezometers is installed at 0, 2, 10, 50 and 100 m from the edgeof the pool (plus one in the pool if possible).

• What materials and methods are required for making andinstalling piezometers?The methods of installing piezometers (foreshaft by drilling, shaftsinking by piling), the constituent material (metal, PVC), the fil-ter and the diameter of the tubes depend on the nature of theterrain and the type of measurement of levels to be performed(instantaneous measurements or continuous recording). If the terrain is not very pebbly loose rock and the groundwaterfairly shallow, it is easy to make piezometers with standardisedfairly thick PVC tubing to prevent distortion. They are installed ina hollow foreshaft excavated with a hand auger, as vertically aspossible. The filter is usually a piece of nylon stocking, attachedto the base of the tube by a steel wire (or clamp) and protectedby a sleeve of gravel if necessary.The best period for installing piezometers (Fig. 38) is mid-sum-mer, when water levels are at their lowest. On loose terrain(sand), it is not easy to work in a saturated habitat.When the foreshaft has been dug (phase 1, Fig. 38), place thepiezometer in it as vertically as possible. Pour some siliceousgravel around it, then pull up the tube by a few centimetres, thuscreating a small permeable sleeve (phases 2 and 3). With theearth taken from the foreshaft, make a fairly liquid mud, thenpour it in and pack it down in the foreshaft around the piezome-ter (phase 4).In habitat prone to flooding, the aerial part of the piezometershould be fairly long to avoid the risk of it being submerged. Toprotect the base of the tube from unwanted infiltrations, it isrecommended that it be placed in the centre of a casing (a pieceof tubing of larger diameter) pushed into the earth to a depth ofaround 20 cm, and filled with soil (phase 5).The piezometer should be capped, but free communication withthe atmosphere should be ensured.For instantaneous measurements of the piezometric level, PVCtubing, 45-50 mm in diameter, is suitable. The foreshaft is thendug out with a Helix auger, 100 mm in diameter (or 125 mm, seebelow). For recording variations in water level, the diameters of

the foreshafts and the piezometers should be adapted to therecording equipment. For a floating system of 80-mm diameter,use a hand auger with a diameter of 150 mm and a PVC tubewith a diameter of 120-125 mm. The foreshaft can be made witha hand auger with a diameter of 125 mm and a PVC tube with adiameter of 95-100 mm may be used, but in this case particularcare should be taken to ensure that the system is vertical.

• How to read the levels in piezometersThe best solution is of course to purchase a limnimetric probewhich will indicate water levels by light or sound. A light probecan also be made fairly cheaply, modelled on the one describedby Heurteaux185. For very shallow groundwater, a rigid probemade of dampening material (a graduated wood rod for exam-ple) will suffice.

• How to extract water from the piezometersIn semi-permeable terrain, water can remain for a long time inthe piezometers. Before any sampling of the water, it is thusadvisable to draw off the water (or even empty the tubes), waitfor a few minutes, then take the water from the bottom of thetube. For this, pumping is necessary. For shallow water, a smallhand vacuum pump will suffice (manual bilge pump, for exam-ple).


1 2 3 4 5Pi

erre

Heu

rtea

ux

Handauger

Stopper PVC tube

Loosesoil

Gravel sleeveCollarFilter

Siltation mud

Casing

Water

Air inlet

Figure 38. Making and installing piezometers

96


c. Vegetation monitoring Grillas P. & P. Gauthier

Vegetation monitoring generally aims to provide evidence of theeffect of habitat changes (hydrological regime or soil thickness,for example) on the whole of the vegetation or on certain speciesin particular. Monitoring involves defining, in advance, referencestate and the range of variations around this “norm”, judgednatural or acceptable. In the case of temporary pools, previousknowledge of the amplitude and frequency of the natural varia-tions, under the influence of meteorological conditions in particu-lar, is very important.

Within the framework of a monitoring programme, two series ofvariables should be measured: those concerning the managementobjectives (of rare, characteristic, invasive species, etc.) and thoseconcerning the biotic or abiotic factors which could explain thechanges. In temporary Mediterranean pools, the choice of methodswill be influenced by:• Characteristics linked to the habitat: - the instability of the vegetation and hydrology,- the surface area, sometimes very small,- the water depth, which can vary greatly (karst pools, turloughs,poljes, etc.) in time and with strong spatial gradients.• Key parameters of the typical vegetation of this habitat:- the number of annual species with a short life cycle,- the frequency of small-sized species,- the impossibility of identifying separate individuals in manyspecies (vegetative multiplication),- the presence of tall plants, which can sometimes be dominant(shrubs, helophytes),- the existence of a seedbank.

Most of the techniques described require data collection over atleast two to three years, and preferably over five to ten years, tobe able to quantify the impact of the natural evolution of thehabitat or of management measures. Given the rapid succession of species, these techniques usuallyrequire measurements taken over the whole of a vegetationcycle. Failing that, managers should target visits in relation to thepeak of vegetation, the visibility or the stage of development ofthe species being monitored, and more generally, the question towhich an answer is being sought.

The inventory

This is a list of the species observed on a site, the compilation ofwhich will require several visits as species succeed one anotherduring the annual cycle. Because of the irregularity of emergenceof some species, this can also require several years of observa-tions. An inventory is especially advisable during exploratorystudies, for drawing up a site assessment and for describing thedevelopment of species richness during restoration or creationprojects167.

Monitoring a rare, threatened or invasive species

Depending on its density at the study site, different protocolsmay be considered.

A very rare species with scattered individuals (easily countable)can undergo a total count, possibly accompanied by mapping ofthe individuals, combined with supplementary data (topography,etc.). The accuracy of the method depends on the probability ofdetection of the species (size, colour, etc.). Mapping will be facili-tated by a marked grid at the study site, thus limiting the risks ofoverlooking individuals or counting them more than once, andabove all enabling the spread/decline of the species to be moni-tored over a number of years (Fig. 39). To enable a populationassessment to be made the count should be supplemented withmeasurements of demographic parameters: reproduction, seedproduction, number of seedlings reaching reproductive maturity,etc.167 To define the real size of the population (decline, stability orincrease), a study of its seedbank (see below) will be necessary.

In the case of a species with greater densities, for which exhaus-tive censusing is impossible sampling using permanent quadratsis preferred. Within a quadrat, the species are characterised bytheir presence/absence, their cover, their frequency and theirnumbers. For the species of temporary pools, which are generallysmall in size, a quadrat with sides of 25 to 50 cm will normallysuffice. Only plants rooted inside the quadrat are counted, butthe main point is to keep a constant criterion between quadrats.The larger the number of quadrats, the greater the accuracy ofthe estimates.The cover is the most commonly used method in the study ofvegetation176, 207. It consists in estimating the projection onto theground of the surface of each species, the vegetation being sub-divided into strata (tree, shrub and herbaceous, for example). Thismethod is only rapid and effective if the researcher is experiencedor the vegetation studied simple (one or more scattered species).The discrepancies between inexperienced observers will increasewith the complexity of the vegetation structure (number of species,diversity of growth forms). For this reason, measurements whichare less accurate but less sensitive to a change in observer arepreferred367. Thus the abundance (or frequency) of a species canbe measured in quadrats divided into squares. For example, in aquadrat with sides of 30 cm subdivided into 9 squares with sidesof 10 cm, the abundance will be measured as the number ofsquares (0 to 9) in which it is present. The quadrats can also be redistributed randomly each year.

Figure 39. Monitoring of a rare or scattered plant species withthe aid of a permanent grid

A B C D E

1

2

3

4

5

97

6. Monitoring

The cover of a species on a given surface can also be evaluatedby the analysis of a photographic image. This method has nowbeen facilitated by the ease of use of digital photography andimage processing. It is suitable for simple communities (1 or 2 spe-cies) on bare soil, as it requires a significant contrast between thesubstrate and the vegetation. The density of Marsilea in dry poolsat the end of the summer could, for example, be obtained in thisfashion.

Monitoring emergent plant communities

Zonation into vegetation belts is often recognised in temporarypools (Chapter 3c), along the hydromorphic gradient. A transect(permanent or otherwise/temporary) is the most pertinentmethod of monitoring the variations in vegetation along thisgradient. In this case, the transect consists of a line establishedperpendicularly to the vegetation belts (Fig. 40) and cuttingcompletely across the pool or as far as its centre. Depending onits size and topography (homogeneity), one or more transects areestablished, in parallel or perpendicular to one another.

Figure 40. Putting in place vegetation transects in temporarypools

Monitoring of vegetation dynamics usingthe quadrat transects method in a pool atMamora (Morocco)

Gril

las

P.

Transect 1Transect 2

Transect 3

Transect 1

Transect 2

98


Monitoring at permanent measurement points, possibly within aprotocol of stratified samplinga per zone, is often preferred: itsdisadvantages in term of representativeness and independence ofthe data are largely compensated for by ease, implementationtime and the ability to identify changes. The permanence of per-manent marker pegs can be a problem in temporary pools wherethey are regularly unearthed because of the winter flooding whichloosens the soils, and disturbance by humans and animals (wildboar, livestock). Discreet marking of plots which are buried andbarely visible above the ground is preferable, even if they are

A transect has the advantage of ease of implementation but thedisadvantage of low spatial representativeness. Different mea-surement methods can be implemented along the transects:• Measurement by points consists in noting all the plants whichtouch a pointer stuck regularly into the vegetation. It requiresmuch time and rigour, and does not enable spatial analysis of thedata (the averages are obtained by species and by transect). • Measurement by segment consists in taking an inventory ofthe species on segments of consistent length (for example 10 cm)arranged continuously (Fig. 41-a) or at regular intervals (forexample 0.50 m) (Fig 41-b). The lengths of the segments and theintervals enable adaptation to varied situations.• Measurement by quadrats follows the same principle as seg-ments but enables, at each point, a larger number of species tobe censused and their abundance to be quantified. This methodthus enables spatial analysis of the abundance data along theenvironmental gradients (Fig. 41-c and d).

Figure 41. Different measurement methods used for monitoring the vegetation along transects

a. Stratified Sampling: When the subject of study has a distinctive and well-knownspatial organisation (as opposed to a random distribution), the sampling protocol isbased on this distribution. For example, if it is thought that the depth of the poolinfluences the species richness, an equal number of deep and shallow pools arechosen, so as not to oversample the most common category (to establish uniformsampling intensity according to a predefined typology).

1 - Continuous transect The plants are counted on identical and continuous segments along the transect line

3 - Quadrat transect The plants are inventoried(presence/absence, counting, etc.)inside quadrats set at regular intervals or continuously along the transect line

2 - Discontinuous transectThe plants are counted on the line, over 20 cm every 40 cm for example

R1

R2

R3 R4R5

R6

R7 R8

R9

R1R2

R3R4

R5R6

R7R8

R9

R1

R2R3

R4

R5

R1

R2

R3

R = reading

99

6. Monitoring

more difficult to locate again. Some markers can be carefullyplaced outside the pool and used, at each reading, to re-establishthe reference axes.

Study of the seedbank

Estimation of the seedbank is necessary for evaluation of the sizeof a population of annuals with dormant seeds or the capacity ofa species or suite of species to regenerate after a perturbation(Chapter 3c). Such a measurement is not generally within themeans of the manager (cost, infrastructure, etc.). Nonetheless, inthe case of a species with high natural-heritage value, managersmay wish to carry this out in collaboration with a specialist.

Study of a seedbank begins with standardised sampling of thesediment (sample boring). The diameter and depth of the core areadjusted to the size of the seeds, the depth of the substrate andthe purpose of the monitoring: generally 2 to 20 cm in diameter.Seeking seeds below 5 cm in depth is only justified in particularcases, such as the burying of seeds by sedimentation, ploughingor disturbance by wild boar (Boxes 38 and 41).

Two techniques with different results can then be envisaged,depending on the objective: direct counting of the seeds or puttingthe seeds found in the soil into germination conditions. Bothrely on relatively intensive procedures (in terms of time andaccuracy).

Direct counting of the seeds is carried out after their extractionby sieving with a series of sieves with meshes of different sizes.

The smallest mesh is generally from 0.15 to 0.20 mm. The seedsare then identified under a binocular microscope. This techniqueprovides an inventory and an estimate of the relative abundanceof the seeds, but does not give any information on their viability.In this way, an overestimation of the viable stocks is obtainedwhich can be evaluated by supplementary germination tests.Such tests require the knowledge of the germination conditionsof the species being researched and can be very complicated tocarry out (pools with over 100 species!).

Indirect counting of viable seeds from seedlings consists inputting soil samples into optimum conditions for seed germina-tion. This method requires an adequate infrastructure (greenhouse,air-conditioned enclosure) for the germination experiments andcontrol of the germination conditions of the plant species. It pro-vides an estimate of viable seeds but tends to underestimateseed stocks: all the viable seeds will probably not germinate.Moreover, this method requires the ability to recognise plants atthe seedling stage, as they will not necessarily reach the adultstage during the experiment.

For bryophytes*, the monitoring problems are more or less thesame as those for vascular plants (Hugonnot & Hébrard, pers. com.),though the use of the transect is less common367. Furthermore,the identification of the species in the field is often more diffi-cult or even impossible for some groups. Sampling for laboratoryidentification, which can disturb the habitat, is thus necessarymore frequently than for vascular plants.

The main methods used according to the objectives pursued aresummarised in Table 20.

Objectives Methods possible Time Other costs Level of knowledge

required

Monitoring of a scattered species Count and detailed mapping ** * *

Monitoring of a more abundant species Permanent quadrats ** * **

Monitoring of a community Permanent continuous transect ** * **Permanent discontinuous transect ** * **Permanent transect of quadrats ** * **

Direct count *** *** ***

Indirect count ** ** ***

Study of the seedbank

Mixed technique *** *** ***

** Inventory Repeated visits to site * *

* = low, ** = moderate, *** = significant

Table 20. Evaluation and objectives ofvegetation-monitoring methods

100


d. Amphibian monitoring

Jakob C.

General points

Monitoring is influenced by the life cycle The methods used for the monitoring of amphibians mainly con-cern the aquatic phase, when the animals are concentrated inpools and, for some species, night sampling. In most cases, visitsmust be synchronised with breeding periods, which are oftenlinked to periods of rain. Sampling of adults is thus constrainedcompared with the sampling of larvae, which can be carried outby day or by night and over longer periods.

Breeding Like other groups of animals of temporary pools, the breeding ofamphibians varies greatly from one year to the next (Box 21,Chapter 3d). It is thus difficult to differentiate fluctuations inpopulations in the long term from variations observed in theshort term. Some species are characterised by considerable flex-ibility enabling them to adapt to interannual variations in rain-fall, while others are more stable (Box 22, Chapter 3d). For themonitoring of amphibians, several parameters are important: thechoice of the period of the sampling, the necessity of repeatedvisits during favourable periods, the importance of monitoringover several consecutive years and the correlation of samplingswith the data of a local meteorological station and the physicaldata of the habitat, for a correct interpretation.

Legislation and protectionAmphibians are protected by law in most European countries. OnFrench territory, all species are protected by law (Arrêté du 24 avril,JO 12 mai 1979) except for Rana esculenta and Rana temporariawhich are covered by special legislation. Thus for all monitoringprojects involving the handling of amphibians, authorisationmust be applied for in advance. This is given by the préfecture ofthe département in France and by the Comunidades Autónomasin Spain. In addition to these administrative procedures, these animals,adults or larvae, must always be handled with extreme care. Theirskin is particularly fragile, especially those species covered withmucus. Handling should be kept to a minimum.

Some advice:• Variability in time: strong interannual variations in breedingcan occur (Fig. 42); for a complete inventory, it is thus advisablefor monitoring to take place over at least three years.• The methods presented are suitable for the small surface areaof temporary pools.• A combination of several techniques in the field is advisable.• The techniques presented are based on the experience acquiredwith the temporary pools of southern France; there are of courseother methods, not dealt with here121, 187.

Methods

The choice of methods depends mainly on the objective sought, butshould take into account technical demands and cost. The resultsthat can be obtained are essentially an inventory, an evaluation ofthe size of the population and demographic monitoring.

The inventory The inventory consists in making up a simple list of the speciespresent on a given site. Depending on the timescale and themethod used, this list of species can vary considerably. The mostconducive period for the observation of amphibians must then bechosen (see Fig. 42) and some verification observations possiblycarried out outside of this period. In southern France, the mostsuitable periods are October-November for the autumn periodand February to April for the spring period.

There are several methods:• Visual detection of the adults preferably takes place at night,with the aid of a torch, close to potential breeding sites. This protocol is easy to follow. It requires a minimum of equip-ment and enables comparisons to be made between sites whenthe observation effort is standardised (number of man-hours).The only constraint with this method is the ability to identify species.Under certain conditions, surveying by day can also yield goodresults, particularly at the time of the emergence of recentlymetamorphosed individuals (May-June, especially in southernFrance). In this case, this involves seeking animals in the imme-diate proximity of the pool, under nearby stones or other objects.

• The auditory count (by night) consists of night sorties to iden-tify the species present by their characteristic songs. The proto-col is simple, the equipment is minimum and the observationeffort (number of man-hours) can be standardised between sites.On the other hand, this method is limited to singing amphibians(some Anura only) and can only be applied under certain meteo-rological conditions (rain, no wind, high temperature for somespecies such as the Western Spadefoot). For large sites, it is moredifficult to implement due to the limited range of the song. Inthis case, it can be combined with transects (cf Chapter 6d).Knowledge of Anura songs is essential, except if recordings aremade and given to specialists.

• Sampling of larvae is carried out by means of a pond net witha fairly large mesh (2 to 3 mm) dipped regularly to different depthsof water in the pool. The collection of larvae should be carriedout with extreme care, as they are very fragile (especially newtlarvae). For identification, they are placed in a fully transparentreceptacle so that the entire animal can be observed. The larvaeshould be released as soon as possible after their identification.Using this technique, an exhaustive list of the amphibians breedingin the pool can be obtained for any given year. In southernFrance, monthly sampling from February to June will theoreti-cally enable all the species to be obtained. Advantages include

Box 55. Exploring a new site

On an unknown site (for example a plateau, or massif with anunknown number of pools), exploration begins by nocturnallocation after heavy rainfall and when there is a fairly high airtemperature (not below 13°C) in autumn (October-November)or spring (February to April, for periods conducive to breeding,see Fig. 42). The localisation of the places (pools) occupied maythen be made by listening, thanks to the vocalisation of somespecies (essentially frogs, Stripeless Tree Frogs). After thislocalisation phase, the usual methods of inventory can beapplied.

Jakob C.

101

6. Monitoring

Figure 42. Monthly occurrence of tadpoles of several amphibian species (pools of Roque-Haute, Hérault) over three years of monitoring(based on Jakob196) in 184 pools at Roque-Haute

■ 1997 ■ 1998 ■ 1999

2000

1500

1000

500

0Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept.

30

20

10


40

30

20

10


6

4

2


15

10

5


6

4

2


2520151050

Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept.

30

20

10


Rain

fall

(mm

)N

umbe

r of

occ

upie

d po

ols

Hyla meridionalis

Pelobates cultripes

Pelodytes punctatus

Rana perezi

Triturus helveticus

Triturus marmoratus

Bufo calamita

Rainfall

102


minimum equipment and results which are comparable betweensites. The method requires knowledge of identification of speciesat the larval/tadpole stage. It can have a considerable destructiveimpact on the vegetation (and on spawn).

• Trapping: there are two main types of traps for this kind ofinventory: - A light trap consists of a transparent plastic cube, with funnel-shaped openings in the sides. There is a source of light inside. Thecube floats on the surface of the water and the openings areunder the water. The tadpoles and larvae are attracted by thelight and remain trapped inside. This method has the advantageof enabling sampling in inaccessible zones and minimises thesampling time and therefore disturbance of the habitat. The costsof the traps (around 100 € each) or the time taken to make themare constraints to be taken into account. Moreover, they areoften inadequate for the entire water column (size, volume of thepool), and can thus only be used to supplement other methods.Some predators of larvae can also enter the traps. - The technique of shelter traps consists in placing artificial ornatural shelters close to the pool to attract amphibians: piece offibrocement, plank, flat stone. These shelters are used by theadults and the larvae at certain times of the year (autumn andspring especially). This enables the species found to be invento-ried during the day and certain important breeding phases to bedated, notably the emergence of the larvae. This technique isespecially effective for newts, the Parsley Frog, toads of the Bufogenus, the Alytes genus and Painted Frogs.

Recommended field guides: for Europe, two recent works areparticularly recommended: Nöllert & Nöllert281 and Arnold &Ovenden17. For France, Duguet & Melki121 give an identificationkey for the adults, the larvae and spawn as well as an audio CDof all the songs, and Miaud & Muratet265 include two identifica-tion keys (one for the eggs and the spawn, and one for the larvaeand the tadpoles) illustrated by photos. For the Iberian Peninsulathe work of Salvador & Garcia Paris334 is excellent for the identi-fication of adults (drawings and photos for identification crite-ria) and larvae (key in form of drawings).

Population sizeTo count the number of individuals of a species, the methodsbecome more time consuming. All depend on the accuracyrequired, the time available and the species present, which havebeen previously identified by an inventory.

• Auditory counts: this method is similar to that describedabove, only here the aim is to quantify male singers. Repeatedcounts in the spring, or in the autumn, can be necessary. The num-ber of animals is usually noted in classes (1, <10, <50, <100, etc.)especially for species in which the male singers appear at thespawning site synchronously (Parsley Frog) or in large numbers(Stripeless Tree Frog, Green Frog). This method is suitable for poolsof small or moderate surface area and in low numbers, but diffi-cult to implement on some sites with a network of neighbouringpools. This is the case for example with the Roque-Haute NatureReserve, Hérault (around 200 pools), for which it is difficult tosample all the pools in any one night. It only applies to relativelyfew species: mainly Stripeless Tree Frog, Green Frog, Parsley Frogand Natterjack Toad.• Counts of breeding adults: the method consists in counting

the number of individuals present on a site. It is effective for

species in which breeding is brief but highly synchronised (CommonToad, Spadefoot) or for species which remain on the breeding sitefor a long time (Great Crested Newt). It is not suitable for speciesin which breeding is spread out over time (Parsley Frog, StripelessTree Frog) or in which the time spent on the breeding sites is verybrief (Painted Frog, Parsley Frog). In all cases, the numbers ofbreeders present is underestimated. This method gives an idea ofthe size of the population and not an exact estimate.

• Spawn count: the method consists in counting, by day or bynight, the spawn deposited by the females. It can enable an excel-lent estimation of the population, or more precisely of the num-ber of females using the site at any given moment. It can only beapplied to a few species: essentially Parsley Frog and Agile Frog.The spawn must be easy to identify (a ball of eggs for the AgileFrog, cigar-shaped sleeve for the Parsley Frog) and deposited overa short period (several days). It cannot be applied to spawn instrings (genus Bufo, Spadefoot) or eggs that are laid separately(newts, Painted Frogs) or laid over too long a period of time.

• Amphibian drift fence: This method consists in placing a fencearound the pool, and traps (buckets or flowerpots) buried insideor outside the fence. Amphibians, especially adults, fall into thetraps when arriving at or leaving the pool. A list of species is thusobtained as well as an estimate of the number of individualsusing the site, the chronology of the arrivals/departures, and thedirection taken. This is an effective method if the soil is fairly loosefor the apparatus to be put in place. The method is not suitable forall species: the Stripeless Tree Frog Hyla meridionalis easilyclimbs over this kind of obstacle. Furthermore, its impact on theenvironment is not negligible, and the risks of predation and mor-tality are high in the captive animals, thus necessitating regularchecks, at least every two days, and thus a major time investment.

• Capture/marking/recapture (CMR)a consists in marking, duringtwo sessions or more, all the individuals captured. Using therecapture rates, an estimate of the size of the population can bemade by some simple calculations. This method presupposes anumber of conditions which are rarely fulfilled in amphibian popu-lations: no emigration-immigration, no mortality, equal probabilityof capture among individuals, etc. It also requires a thoroughknowledge of the biology of the species if it is to be safelyapplied. Certain species (Spadefoot, Painted Frog) remain on the

Checking the traps around an amphibian drift fence (Roque-Haute)

Roch

é J.

103

6. Monitoring

breeding site for a very short time, with a high turnover from oneevening to the next, which invalidates the method.In addition to an estimate of the population size, the techniqueenables information to be obtained about population dynamics,through individual life histories (see Demography below).Marking methods vary according to the species. Non-individualmarking is often sufficient for an estimate of the population size.For this, several methods exist: photo-identification, markingwith dyes, amputation of a digit, tattooing, installation of anelectronic chip. Individual marking gives access to more informa-tion: individual survival with the aid of CMR techniques, sitefidelity, etc. Photo-identification is possible in species with acomplex ventral or dorsal design (salamanders, Great Crested andMarbled Newts, Yellow-bellied Toad, Spadefoots). It meets itslimits when the population is large (larger than 200 individuals)because of the time needed for the recognition of the animal.Marking by electronic chip, implanted under the skin, is an alter-native method, valid for all species of sufficient size.

DemographyHere, the aim is to find answers to precise questions, such as “Isthe recruitment* in young individuals in the population sufficientto ensure its survival?” or “Is the population stable, in decline orincreasing?” To reply to this type of question, the most appro-priate method is CMR, which consists in studying what becomesof a representative sample of individuals over time (life history ofindividuals). An alternative method consists in analysing thestructure of the population and its development over time.

• Estimation of individual survival rates and the demographictrends of the population: from the technical point of view, themethod consists in capturing an adequate sample of individuals(representatives of the population), marking them durably, andmonitoring them over time. For the capture, one of the tech-niques previously mentioned is used (night captures on breedingsites, fences with traps, shelter traps, etc.). Individual markingmakes use of the techniques mentioned above. The quality of theresults will depend on several factors: the proportion of indi-viduals marked in the population, the recapture rates of theseindividuals and the duration of the monitoring. To estimate thesurvival rate in any given year, a three-year monitoring pro-gramme is necessary (one year bracketed by two years); to esti-mate a trend, several years are necessary (the generation time ofthe species at least). It thus involves a technique that is timeconsuming and requires great rigour. It can only be applied invery specific conditions: a well-defined population in space andtime, thorough knowledge of the biology of the species and thefactors which can influence the survival of the animals. It is thusnot a routine technique for a manager.

• Demographic structure of the populations and cohort* moni-toring: the method consists in estimating the relative importanceof the different cohorts (years of birth or age classes) in the popu-lation. To identify the cohorts, measurements of the size or weightof the animals can be used (classes of size or weight) or their ageestimated using the technique of skeletochronology* (see Jakobet al.199). This method is applied to a toe clipped from a living ani-mal. It enables the annual growth layers to be read, as well as, insome cases, the birth line, which gives direct information aboutthe age of the individual. As it is difficult to implement, skeleto-chronology is limited to authorised specialists and not reallyappropriate for monitoring purposes.

In practice, allowing for exceptions, it is best to stick to mea-surements of size which separate only some age classes (firstyear, second year and adults, in most cases) but which can revealmajor dysfunctions, such as an absence of recruitment over sev-eral years, for example.

The various methods described are summarised in Table 21 andevaluated in terms of time, cost and level of knowledge required.

a. Experiments which mark individuals and skeletochronology* which require theamputation of a toe from an animal are not benign. They require preliminaryrequests for authorisation in which it is clearly stipulated that the animals will notbe killed. In France, these requests should be presented to the DIREN, which forwardthem to the Ministère de l’Ecologie et du Développement Durable.

Method Objective Time Cost Knowledge necessary

Effectiveness of the technique

Inventory * * * *

Population size ** * * *Demography - - - -

Inventory * * ** **

Population size ** * ** **

Demography - - - -

Inventory ** * *** ***

Population size - - - -

Demography - - - -

Inventory * *** *** **

Population size - - - -Demography - - - -

Amphibian drift fences Inventory ** ** * ***

Population size *** ** * **

Demography *** ** ** ***

Inventory - - - -

Population size ** ** ** **

Demography ** * *** **

Inventory - - - -

Population size *** *** ** ***

Demography *** *** *** ***

* = low, ** = moderate, *** =significant

Non-individual marking

Individual marking

Night observation

Auditory count

Pond net

Larvae traps

Table 21. Evaluation of amphibian-monitoring methods

104


e. Macrocrustacean monitoringThiéry A

Unlike insects, invertebrates with exclusively branchial respira-tion (including branchiopod crustaceans) spend their entire lifein a pool in two states: • an active state, in periods of flooding, during which they gothrough their biological cycle (growth, nutrition, reproduction,etc.) passing through the larval, juvenile and adult stages,• a diapause* state, in dry periods, during which the populationsonly survive in the form of resting eggs.When there is water in the pool, only a fraction of the popula-tion is active; the rest of the population can remain in the sedi-ments in the form of eggs for several years.The ease of the direct observation in situ of an individual dependson the age of the organisms, and thus their stage of developmentand their size. Because of the synchronisation of the hatchingsafter flooding begins, all the eggs which have completed theirdiapause hatch in a few hours or days after submersion (dampe-ning or rehydration alone of the sediments is ineffective). Individualsborn on the same date will therefore develop as a cohort*, whichfacilitates the determination of the growth stages. During thefirst weeks of submersion, depending on the specific growthspeeds (Fig. 43), only larvae or juveniles are found, which are dif-ficult to observe and identify (small sizes, transparent).

Methods

InventoryThe inventorya is based on a series of qualitative samplings with anet with a mesh of 100 to 200 µm. The frequency of the samplingsand their date will depend on the date and duration of submer-sion. For example, for a submersion in October and a drying-out inApril, at least three samplings must be made: respectively 15 days,two-three months and three months after submersion. Samplesare taken from different zones of the pool, in open water, amongrooted or floating macrophytes, etc., to include all the differenthabitat subdivisions. In all cases, the samples are taken whiletaking into account the shadow made by the observer in sunnyweather, as well as the wind which sends out shock waves dueto the movements of the operator. Branchiopods are particularlysensitive to these disturbances and can rapidly escape.For identification, it is sometimes possible to photograph theindividual in a crystallising dish, then release it. However, thiswork is more generally carried out at the laboratory after fixationin formalin diluted to 8-10% vol./vol. in water (70° alcohol some-times causes excessive deformations, as well as the disappearanceof colours through the dissolution of pigments). It is useful to notethe particular colourations in vivo. Trapping techniques (nets,baits, underwater light traps, etc.) do not give conclusive results.An inventory of aquatic forms should be supplemented by a care-ful search for resistant forms during the dry phase. This methodwill be usually entrusted to a specialised and competent practi-tioner. Sampling should take place in various parts of the drypool. Though rigorous methods have been described recently,including that of Maffei et al.246, for reasons of simplicity, we willretain the transect method (cf Chapter 6d) with:• sampling at the centre, at the deepest point (during the dryphase, female anostracans are able to gather together and releasetheir eggs here),• sampling at the periphery, a little below the maximum waterlevel (some eggs float and, under the influence of the winds, canaccumulate on the banks, particularly under the prevailing wind).

In Notostraca, the females of Triops have a marked tendency toagglutinate their eggs on gravel378, 385 while the females of Lepi-durus stick them onto leaves or bury them partially in the sedi-ments. In the case of Triops, the centrifugal egg laying (at thewater’s edge) is an adaptation which enables the eggs to hatchonly when the water level is at its highest: the duration of floodingwill then be sufficient for the juveniles to reach maturity. Eggs are looked for by washing the sediments in a sieve with a100-µm mesh or by flotation with water saturated in sugar orCaCl2 (method of separation by density difference). In addition, itis possible to look for macro-remains, i.e. fragments of stronglychitinised or keratinised cuticule (the mandibles of Lepidurus,telsons of Triops, antennae of Branchipus males, fragments ofSpinicaudata carapace, for example, Fig. 44). This method hasbeen tested with success in biotopes which have remained dryfor several years in North and sub-Saharan Africa380.

It is always useful to detail the conditions in which the specieshas been collected. The most important variables for crustaceansare mineralisation (measured by electrical conductivity), trans-parency, temperature, the dissolved oxygen concentration, thepH and the depth of the water380 (Chapter 3e). These measure-ments can be obtained by a research consultancy or universitylaboratory.

Figure 43. Speed of growth of macrocrustacean larvae (based onThiéry380)

a. The data collected will be put on a recording form destined to contribute to thenational inventory initiated by the Museum National d’Histoire Naturelle in Paris andthe Service du Patrimoine de Paris (model annexed to the second volume).

45

40

35

30

25

20

15

10

5

00 6 16 26 36 46 56 66

Time (days)

Leng

th (

mm

)

Tanymastigites jbileticaTriops granariusCyzicus bucheti

105

6. Monitoring

Population monitoringMonitoring the frequency, abundance and density of populationsper litre or per unit surface area (m2) and the sex-ratio* is moretime consuming and requires more rigour. In this case the pool isdivided into numbered cells, some of which (at least 3) are ran-domly chosen for a sample (Latin Square technique) of knownvolume. The mean and variance enable the distribution of thespecies at time t to be established. For example, this protocolapplied to Lindiriella massaliensis in the pool of Bonne Cougne(Var, France) has shown clumped individuals in December, then arandom distribution in January, before the spontaneous disap-pearance of the population in February. In shallow water thesamples are taken with a bottomless cylinder275, 375, 380. Sinkingit a few centimetres into the sediment ensures that the base iswatertight, which enables emptying or filtering of the watercolumn, the volume of which is known (area of base x depth).When the depth exceeds 50-60 cm, a net is used, which filters avolume of water determined by the diameter of the opening andlength of the sweep (1 or 2 m in general). The use of artificialsubstrates can supplement the usual methods (Box 56). Countingis done under a binocular microscope, and the counts are madeeither using absolute figures (juveniles, adults) or in the case oflarge numbers, using the Frontier151 method, which defines classesof abundance according to a geometric progression:• Mark 0 0 individuals,• Mark 1 1 to 3 individuals,• Mark 2 4 to 17 individuals,• Mark 3 18 to 80 individuals,• Mark 4 80 to 350 individuals,• Mark 5 351 to 1,500 individuals, etc.

Determination of the sex-ratio is useful in the monitoring ofpopulations, the ratio being susceptible to variations accordingto the species and the time scale. Techniques based on individualmonitoring cannot be used with crustaceans: the moult does notallow for colour marking, and cutting off a cercus, or an ampu-tation, as can be done with amphibians, results in the rapid deathof the individual from haemorrhaging (open circulatory system).Other methods can be used for the study of macrocrustaceanpopulations, but these are relatively burdensome to implement

and can require equipment which is rarely available to managers,as well as highly specialised technical skills. When they are neces-sary, these methods (described in summary below) can be imple-mented by specialist teams.

Growth curves/life history tables require the establishment ofcorrelations between the total length or the length of a bodypart, such as the telson, and the age of the individuals. Generallyspeaking, anostracans are measured from the front to the extre-mity of the cerci inclusive, notostracans by the length of thecarapace and Spinicaudata by the length of the valves. The mea-surements are made on millimetre paper (rapid estimations) orwith an ocular micrometer under a binocular microscope.

Fecundity is measured by the number of eggs in each layingduring the life of the female. By way of example, the number ofeggs laid grows exponentially, from 2 to 350 per clutch, with theage of the female (8 to 17 mm). Knowing that she can laybetween four and six times during her life, the number of eggsproduced can be estimated as over 650. In the case of Spini-caudata (Cyzicus, Leptestheria, etc.), a female can lay several thou-sand eggs during her lifetime.

Biomass measurements require a 10% formaldehyde fixation (doesnot deform and does not dissolve or only very slightly dissolvesfats: 6 to 8% of biomass loss compared with 25% in alcohol),drying in a desiccator (65°C), cooling, then the weighing of indi-viduals380 (singly or in lots of 10). The formulation of a specificregression equation Length (L mm) against dry weight (W mg)will serve for other habitats without having to repeat these opera-tions.

In the context of studies of metapopulations*, methods using amolecular tool (genetic structure of the populations, polymor-phism of the loci, microsatellites, etc.) enable populations to becharacterised (intra-site stability) and their isolation, or their inter-population relations within an ensemble of sites constituting afragmented range, to be quantified (see Bohonak39 and Bren-donck et al.57, for examples in Anostraca).

A

D

BE

F

C

Figure 44. Remains of macrocrustaceans found in sediment (based on Thiéry380)A, B. Anostracan: antenna of Branchipus schaefferi and Tanymastigites jbileticaC, D, E. Fragments of cerca of cephalo-thoracic shield, mandibule of Triops granariusF. Concostraca: fragment of pincers of Leptestheria mayeti

106


f. Insect monitoring Thiéry A.

Inventory The methods described for macrocrustaceans are also valid forinsects. However, for the inventory of a biotope, the method ofnight hunts with a UV lamp against a white sheet can be added.This type of trap is particularly effective at the beginning of thesummer, a period in which many insects metamorphose. Thesearch for exuviae, as in the case of dragonflies (Odonata), willalso be very useful163 for the inventory.Adults may also be marked to estimate numbers using the capture-recapture method (De Lury in Lamotte & Bourlière219), as hasbeen done for aquatic dytiscid Coleoptera104.The inventory can be semi-quantitative. The classification pro-posed below165 distinguishes five groups: fundamental, constant,associated, incidental and occasional species. These groups aredefined using all the samples by the relative abundance of thespecies (Ar = number of individuals of the species a x 100/num-ber total of individuals collected) and their frequency (F = numberof samplings where the species a is present x 100/number totalof samplings):• Fundamental: F > 50% and Ar > 10%,• Constant: F > 50% and Ar <10%,• Associated: 20 <F <50% whatever the value of Ar,• Incidental: 5 <F <20%,• Occasional: F <5%.

Box 56. A new method of sampling in a still water habitat

Although for running-water habitats, standardised tools havebeen developed to sample and characterise the faunisticassemblage, still water habitats do not have methods enablingevaluation of their diversity or monitoring of their changesover time (in response to management operations at pools, forexample). For several years now, tests of artificial substratesacting as substrates for colonisation have taken place, whichwill enable the abundances of insects to be standardised371.They are made from natural, (gravel, wood, litter, etc.) or arti-ficial (tiles, bricks, plastic plants, etc.) materials.

This method, which is being developed (Scher & Thiéry, com.pers.) at temporary pools associated with motorways, is basedon the use of standard artificial substrates (plastic aquariumplants, brushes, bath sponges, etc.). Initial results have shownthat, for the majority of taxa, a minimum duration of exposureof three weeks is necessary. They show that different inverte-brates are attracted depending on the substrate and their modeof life (Tab. 22). Oligochaetes, benthic burrowing organisms,are dominant in the “brush” substrate, while the swimminglarvae of zygopteran Odonates and the ephemeropteran Cloeonprefer to colonise substrates in open water. Similar results arenoted for the trapping of the larvae of Chironomidae andostracod crustaceans.The use of artificial substrates enables the impacts of mana-gement on shallow still habitats to be qualified, and presentsadvantages in terms of cost, standardisation, repeatability andease of use.

Scher O. & A. Thiéry

plant(mixted)

Brush (benthic)

Scrapers (pelagic)

min 63 595 14max 379 8929 2319

min 13 15 24max 63 60 143

min 15 3 5max 35 27 186

min 19 60 48max 107 298 286

min 11 21 124max 100 354 1981

Type of substrate

Oligochaetes

Ephemeroptera

Odonata

Chironomidae

Ostracoda

Density per litre

A method of sampling invertebrates: the installation of artificial substratesas colonising aids

Table 22. Differential attraction of invertebrates in relation tovarious artificial substrates

Sche

r O.

107

7. Education and communication Genthon S.

Mediterranean temporary wetlands are gradually disappearingand there is usually general indifference to this, as the generalpublic has a poor understanding and knowledge of these habi-tats. Informing and raising the awareness of those who will havean impact on their future is thus essential.

Communication: bringing temporary pools and theirriches to the attention of the public

Legislative protection and habitat management are not in them-selves sufficient to protect temporary pools. Informing and raisingthe awareness of the public is essential, not only to prevent pol-lution and degradation, but also so that the richness of thesepools can be taken into account with regard to physical planning.Improving knowledge of temporary pools and demonstrating thevalue of managing them to a wider public will help to ensurethat these wetlands enjoy lasting protection.

Communication StrategyThe diversity of stake-holders in these habitats makes it essentialthat prior discussion takes place regarding the identification ofthe target public and the establishment of a proper strategy toinform users and modify their behaviour. In addition to information,this also means involving the public in the protection of tempo-rary pools through concrete actions on the ground or localevents.

Communication will be effective if a study of the use of the siteby the public is carried out in advance. It enables the needs andexpectations of each identified public user group to be known.The choice of communication supports results from these needsas well as the objectives fixed by the manager (Tab. 23).The framework tool is the communication plan which definesobjectives and plans awareness-raising operations over severalyears (three to five years). It can be integrated into the manage-ment plan of the site.The objectives of public awareness-raising often take the involve-ment of local populations into account. It is they who have animmediate impact on the protection of the temporary pools intheir area.

The public and information tools In most cases, the manager should provide information to thefollowing:• town and country planners, farmers/livestock rearers, etc.,likely to inadvertently destroy pools through modifications intheir hydrology or by public works (urbanisation, the fire fightingservices, tracks and roads, etc.),• walkers (numerous problems linked to the over-frequentationof sites),• decision-makers and elected representatives responsible forthe planning and development of their territories and local poli-cies,• the media which diffuse information,• children and young people, future players in the managementof temporary pools (see paragraph 2),• owners of sites and their surroundings.

To inform and involve the public, managers have several toolsavailable, some of which have been produced within the frame-work of the LIFE “Temporary Pools” project (Box 57): • for local populations: programmes of events and visits, infor-mation panels, reception infrastructure, exhibitions, nature festi-vals and other local events, etc.• for elected representatives and decision-makers: brochures,leaflets, videos, site visits, inauguration of local events, informa-tion campaigns, etc.• for children and young people: educational trips, events inschools, reception of trainees and training, etc. • for the general public: nature workshops, events, informationbulletin, brochures, leaflets, Internet site, videos, features in themedia (local newspapers, TV), etc.• for the media: communiqués and press packs, invitation toevents, etc.• for scientists and managers: information bulletin, annual reportof activities, Internet site, etc.Tools for the general public can, of course, be used for all otherspecific public groups.

Some tools which have proved their worthNature workshops are good ways of involving the public in theprotection of temporary pools, by providing information aboutconservation issues. In this way volunteers participate concretelyin the conservation of their natural heritage50.The regular organisation of local events keeps the populationinformed: nature festival, exhibitions, slide shows, conferences,art competitions in schools, etc.Guided visits help a wide public find out about temporary poolsin the field.The information documents should be comprehensive, illustratedand practical: leaflets, information bulletins, annual reports ofactivities, etc. Their effectiveness also depends on their distribu-tion, which should be planned in advance.Multimedia (Internet) enables a wide diffusion of information, butit is especially useful in helping to put those involved into a net-work.The effectiveness of information and events is even greater ifawareness-raising initiatives are made in partnership with localplayers and/or through networks in which the manager partici-pates. Regular events organised around temporary pools enablemore and more people to become interested in the protection ofthese habitats.

Environmental education: pools are good teaching aids

Children particularly appreciate temporary pools which areecosystems on their scale. Carrying out educational activitiesaround a temporary pool becomes almost “child’s play”. Throughnature trips and environmental education projects, young peopleacquire a naturalists’ knowledge of the habitat, increasing theirunderstanding of how it functions and enabling them to takepart in discussion on the protection of the pools. A sensitive and imaginative approach is also important for creat-ing an emotional link with the natural environment, which willinfluence the behaviour of the future. Children also help to raiseawareness among their parents.Temporary pools are also good teaching aids for passing onexpertise, notably of techniques of nature observation and theuse of observation equipment (methodological objective).

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Mid-term objectives (driven from the management plan)

1. Introduce the Reserve and raise awareness among the public, in particular young people, of nature protection

Schools - comic strips

(Reception of visitors, programmes of events and educational modules)

- nature books and educational tools

- information and interpretation panels General public- Educational notes

2. Increase awareness-raising of the local population

- information stand and floral exhibition

- travelling exhibition- documents for the general public (see objective n°3)

- nature workshops - open days - occasional evening events (slide show, etc.) - contact with local media - consultation of local population - involvement in local nature events

- information documents, multimedia (Internet)- regional, (nature, environment festivals, etc.) or national events (fairs, salons, etc.), relations with the media, World Wetlands Day

- Internet site (http://roque.haute.free.fr)

- information stand, posters and promotional documents

Partners - annual report of activities

- Newsletter from Roque-Haute- Reserve information bulletin

Media - communiqués, press packs, etc.

4. Pursue the involvement of the Reserve in professional networks (Cooperation, exchanges of expertise and experiences in the management of natural habitats and environmental education)

Example 1: LIFE “Temporary Pools” project

General public, decision-makers

- Leaflets, information panels, video on temporary pools

Example 2: Network of protected natural spaces in Languedoc-Roussillon

- Newsletter of Regional Network (information bulletin)Managers of natural areas and partners

5. Promote scientific research on the Reserve

Researchers, naturalists and scientists

- proceedings of the 1998 symposium (Periodical Ecologia Mediterranea)

Partners and general public

Target public Which document?

Local population, Reserve users, elected representatives and tourists, etc.

3. Provide information about the Reserve and enhance its policy of management and protection among different publics by

General public - leaflets, brochures, themed information sheets (archaeology, etc.)

Table 23. Publication choices for the Roque-Haute Nature Reserve (AGRN.RH - Hérault)

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7. Education and communication

The “Temporary Pools” educational module, produced within thecontext of the LIFE “Temporary Pools” project, thus offers teachersand animators practical tools for organising events around thesehabitats.The framework tool which enables environmental education tobe developed around temporary pools is the interpretation plan59.It provides a list of resources, analyses the educational potentialsof the natural area and defines what can be exploited, depend-ing on the fragility of the habitat and the organisational constraints(duration, interest, etc.). It also helps in prioritising objectivesand selecting target publics.The educational initiatives are always carried out in accordancewith the priority conservation objectives of the natural heritageof a site.

Training/Cooperation: exchanging experiences andbeing involved in networks of players

The involvement of the manager in regional (GRAINE, CPN, etc.),national (ATEN, Réserves Naturelles de France, Espaces Naturelsde France, etc.), or even international, networks enables the techni-cal and sometimes financial means to be obtained to carry outawareness-raising initiatives. It also ensures that a wider publicis reached and is a means of exchanging experiences.The development of common tools helps to create common termsof reference and raise awareness among those involved in envi-ronmental education (teachers, animators, trainers etc.). In addi-tion, as the production of communication aids is often costly, itcan be useful for smaller establishments to produce commontools in order to share the costs.

Above all, working within a network enables teaching methods tobe exchanged and encourages local institutions/organisations(schools, universities, associations, etc.) to get involved with theirlocal sites. All these actions contribute to better integration ofthe natural area into the local socio-cultural fabric. Local prota-gonists will be all the more ready to help with the protection oftemporary pools if the site becomes an integral part of local life.

The LIFE “Temporary Pools” project has built up a preliminary net-work of animators and technicians who are involved with tem-porary pools following a common training programme. A seminardesigned to develop events around temporary pools in 2001 broughttogether for the first time managers and events organisers to

Box 57. Main achievements of the “awareness raising”section of the LIFE “Temporary Pools” project

The LIFE “Temporary Pools” project (1999-2004) has enabled arange of information tools to be produced common to the threeregions of southern France: Corsica, Languedoc-Roussillon andPACA:Brochures and leaflets were widely distributed during theawareness-raising campaign among decision-makers andelected representatives (mailing) and the national informationcampaign.The onsite information panels raise the profile of the local natu-ral heritage; they are supplemented at one of the sites (Plainedes Maures) by a travelling exhibition which will circulate inthe various communes concerned.An educational module delivers practical advice and informa-tion to teachers and animators so they can organise educa-tional projects around temporary pools.The events organised for European Green Days or local naturefestivals help raise awareness among very varied sections ofthe public. They are very effective in involving local popula-tions.Regular contact with the media contributes to a broad diffusionof information, both at local level during, events or activities,and at national level, for press campaigns. It is important toregularly inform the media.A “Temporary Pools” discussion forum enables data to beexchanged and experiences to be shared regarding both envi-ronmental education and the management of pools. This newnetwork of players has been developed thanks to the Internet:http://fr.groups.yahoo.com/group/mares_temporaires.A TV documentary on Languedoc-Roussillon was made in2001. This video has been distributed to resource centres(libraries, etc.) and decision-makers. It has been used forregional events and during the campaigns of awareness raisingamong elected representatives, to obtain support for projectsfor the protection and management of temporary pools. This12-minute long film presents a portrait of several temporarypools in Languedoc-Roussillon, their natural richness, the threatsthey face and initiatives to protect them.

These tools have reinforced the awareness raising initiativesalready carried out locally before this project (reception of visi-tors, activities, educational events, etc.).

Genthon S.

Educational visit to the Roque-Haute pool: measuring the water temperature

Corb

inea

u N

.

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share their experiences with regard to wetlands events, and dis-cuss events which could be transferred to other sites. An Internetforum, the “Temporary Pools Club” enables exchanges to be madeand educational tools to be put online (http://fr.groups.yahoo.com/group/mares_temporaires). The educational module produced bythis LIFE “Temporary Pools” project is the culmination of this cap-italisation of a variety of experiences.

In conclusion, environmental communication and education, andthe involvement of the manager in professional networks, con-tributes to furthering knowledge of Mediterranean temporarypools and thus to their protection. It is a long-term investment,designed to change behaviour and to integrate these wetlandsinto local planning and development.

Roch

é J.

A visit by experts from the LIFE “Temporary Pools” project to the Plaine des Maures

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Glossary

Aggradation: Situation resulting from gradual infilling by accu-mulated material (soil, silt, sand, gravel, etc.).Allopatric speciation: formation of a new species which occurswhen two populations are separated by a biogeographical barrierpreventing interchanges of genes (= as opposed to sympatricspeciation, without geographical isolation).Anemochory: mechanism of dispersal of seeds, spores, eggs etc.of certain animal and plant species by the wind.Angiosperms: flowering plants whose ovules are containedwithin a closed cavity, or ovary. Includes the majority of large andmedium-sized terrestrial plants.Anoxia: refers to the absence of oxygen in the environment.Autogamy: (= self-fertilization) mode of sexual reproductionresulting from the union of two gametes (male and female) pro-duced by the same individual animal or the same flower. Biocenosis: set of living organisms, animal and plant, occupyingthe same biotope.Biogeography: branch of biology dealing with the geographicaldistribution of plants and animals.Bryophytes: group comprising both mosses and liverworts.Charophytes: specialised algal group consisting of one family,the Characeae, characterised by the whorled structure of thethallus and by the highly complex structure of the reproductiveorgans (antheridia and oogonia).Cohort: set of individuals which have experienced the sameevent at the same time (individuals born at the same time orbreeding at the same time in pools, for example).Connectivity: Facilitation of the movement of individuals of aspecies between local sub-populations to form a single func-tional demographic unit.Diapause: period during which metabolic activity and the devel-opment of an insect is suspended at a particular stage (egg, larva,nymph or adult), as a result of the action of internal or externalfactors. Dormancy: temporary physiological state among certain plantorgans, characterised by reduced metabolism and triggered byunfavourable external conditions. Only ad hoc microclimatic orphysiological conditions can bring this state to an end by breakingdormancy.Ecophase: during its life cycle, a species passes through differ-ent stages (egg, larva, juvenile. etc.). An ecophase corresponds toone of these stages having a different ecology from the otherparts of the cycle.Electrical conductivity of water: simple measurement of theconcentration of ions in the water; conductivity, measured inSiemens, is the opposite of electrical resistance.Endemic: used of a species exclusively confined to a given bio-geographical area, often of limited extent.Endorheic: refers to lacustrine biotopes (lakes, pools, etc.) whichare situated in the floors of closed continental basins which aretherefore lacking in outlets.Ephemerophyte: used of a plant with a very brief vegetativecycle.Foliaceous appendage: arthropod appendage, enlarged in theshape of a leaf, playing a role in the trapping and filtering of foodparticles, and in respiration among crustaceans. Freshwater: used to describe organisms that live only in freshwater.Gemmiform: bud-shaped.

Genotype: the ensemble of genetic characters possessed andtransmitted by an organism.Geophyte: plant species which withstand the unfavourable sea-son thanks to the presence of bulbs, rhizomes or any other typeof underground reserve organ (see glossary, vol. 2). Generalist: refers to species which are capable of colonising awide range of habitats and as a result often have a very widegeographical distribution.Genetic bottleneck: sudden decrease in the size of a populationassociated with a decrease in the total genetic variability. Gyrogonites: calcified female fructifications produced by charo-phytes, corresponding to fossil or living forms after dispersal.They are invariably made up of five cells in the form of left-handed spirals, joined at the tips.Heliophilous: used of a plant which grows in conditions ofstrong sunlight.Helophyte: marsh plant whose budding parts, which enable it tosurvive during the bad season, are laid down in the sediment,while in the good season they develop an aerial structure whichextends above the water surface (Reed, for example).Hemicryptophyte: perennial herbaceous plant whose buddingparts, which enable it to survive during the bad season, remainon the surface of the soil, at the very base of the stems (or of thetuft for caespitose Graminae) (see glossary, vol. 2).Hydroperiod: period during the year when the pool containswater.Hydrophyte: plant that lives in an aquatic environment (WaterMilfoils, Water Lilies).Hygrophilous: organisms dependent on biotopes characterisedby high soil water content.Inbreeding depression: interbreeding by closely related parentsleading to the production of individuals of poorer quality.Life-history traits: significant characteristics of the life cyclethrough which an organism passes and more particularly thoseassociated with strategies for survival and reproduction.Mesohygrophilous: organisms dependent on biotopes charac-terised by medium soil water content.Metapopulation: Set of populations that are interconnected viamigration events (gene flow) and are subject to extinction andrecolonisation. This concept may be extended to include any setof populations developing in a more or less independent waywhich are, however, interconnected through rare instances ofmigration.Minimum effective number: number of actually reproductiveindividuals in a population at a given time. This number willalways be less than the number of individuals present in the pop-ulation, since a proportion of the individuals will not be repro-ductive (senility, absence of mates, harem formation, etc.).Nutrient: simple substance which is capable of being assimilatedby an organism without being broken down by digestion (forexample phosphate, nitrate, etc.).Oligotrophic: describes nutrient-poor water (low in nitrate,phosphate, sulphate): its opposite is “eutrophic”.Oospore: Female fructification found in charophytes, formedfrom a spore with a resistant shell.Pioneer: individual or species which establishes itself at an unin-habited site, for example following disturbance.Poikilotherm: describes an animal whose body temperaturevaries with the temperature of the environment where it lives(reptiles, insects or crustaceans, for example).Propagule: any part of an organism, produced by asexual or sexualreproduction, capable of producing a new individual.

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Quiescent: state of temporary suspension of development of aninvertebrate triggered by unfavourable ecological conditionssuch as drought. Release from quiescence takes place immedi-ately after the return of favourable conditions. Recruitment: the adding of new individuals to a population.Recruitment takes place through reproduction, immigration andrestocking.Rhizoid: hair-like rooting structure, particularly among mosses.Sessile: Botanical: an organ (leaf, flower) having no petiole orpeduncle. Zoological: microorganism attached to a support (stem,rock, etc.). Sex-ratio: ratio of the numbers of male and female individuals ina defined population.Skeletochronology: method of determining the age of a verte-brate (amphibian in this work) by counting the growth lines vis-ible in cross-sections of the phalanges or the humerus.

Stripping: action consisting in removing the overlying layer orthe root mat.Therophyte: synonym for an annual plant, a herbaceous plantwith a very short reproductive cycle, lasting a few months or incertain cases a few weeks, which survives the bad season in theform of seeds. (see drawing by Raunkiaer, vol. 2).Trophic: everything relating to nutrition among plants and ani-mals.Tuberiform: tuber-shaped.Vegetative reproduction: mode of reproduction of a plantspecies using vegetative organs (stolons, rhizomes, tubers, etc.).Vicariant: used of animal or plant species that are taxonomicallyclosely related and which inhabit environments with similar eco-logical characteristics in different geographical regions.Water-level range: distance between the lowest and highestwater levels of a body of water.

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