00 colophon premessa - [email protected]/2176/1/23_lasen_scariot... · 2009....

Edited by: Sönke Hardersen1, Franco Mason1, Franco Viola2, Dario Campedel3, Cesare Lasen4, Michele Cassol5.1 Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, “Bosco Fontana” di Verona2 Università degli Studi di Padova3 Uffi cio Territoriale per la Biodiversità di Belluno4 Feltre (Belluno)5 Sedico (Belluno)

Scientifi c board: Paolo Audisio (Sapienza Università degli Studi di Roma), Marco Bologna (Università Roma Tre), Alessandro Minelli (Università di Padova), Sandro Ruffo (Museo civico di Storia naturale di Verona), Augusto Vigna Taglianti (Sapienza Università degli Studi di Roma).

General coordination: Franco Mason

Editing and graphic design: Mara Tisato (Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, “Bosco Fontana” di Verona).Maps (Pages: 38, 313, 314, 315, 326, 336) and image editing: Monica Sommacal (Uffi cio Territoriale per la Biodiversità di Belluno).

English translations: Maria Cristina Bruno (Pages: 17-24, 27-33, 35-43, 45-57, 59-68, 79-88, 117-124, 125-128, 129-151, 153-179, 291-296, 309-321, 325-334, 335-348, 349-361, 395-402, 403-414, 437-439, 441-447, 449-459).Revision of english texts: Valerie Matarese (Pages: 69-78, 89-100, 101-116, 181-194, 195-217, 239-251, 253-259, 261-273, 275-290, 297-308, 363-376, 377-394, 415-423, 425-435).

Additional scientifi c editing: Alessia Gibertoni, Chiara Morganti; Gianluca Nardi & Daniel Whitmore (Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, “Bosco Fontana” di Verona).

Cover photo: Torrente Caorame, Vincheto di Celarda Nature Reserve (by Gabriele Zuppati).Back cover photos: from left to right (by Gabriele Zuppati, Monica Sommacal, Gabriele Zuppati, Sönke Hardersen, Salvatore Danieli).Photos: pag. 25 (by Sönke Hardersen); pag. 323 (by Mauro De Bernardo).

Quotation-sample of single contributions:Gatti E., 2008. Analysis of the Cerambycidae (Coleoptera) from Vincheto di Celarda Nature Reserve, pp. 129-151. In: Hardersen S., Mason F., Viola F., Campedel D., Lasen C. & Cassol M. (eds.), Research on the natural heritage of the reserves Vincheto di Celarda and Val Tovanella (Belluno province, Italy). Conservation of two protected areas in the context of a Life Project. Quaderni Conservazione Habitat, 5. Arti Grafi che Fiorini, Verona.

Quotation-sample of the volume:Hardersen S., Mason F., Viola F., Campedel D., Lasen C. & Cassol M. (eds.), 2008. Research on the natural heritage of the reserves Vincheto di Celarda and Val Tovanella (Belluno province, Italy). Conservation of two protected areas in the context of a LIFE Project. Quaderni Conservazione Habitat, 5. Arti Grafi che Fiorini, Verona 461 pp.

© Copyright – Ministero delle Politiche Agricole Alimentari e Forestali, Corpo Forestale dello Stato. Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale “Bosco Fontana” di Verona.

ISBN 978-88-87082-98-2

Printed on FSC certifi ed paper.

Publication cofi nanced (50%) by the European Commission and Ministero delle Politiche Agricole Alimentari e Forestali, Corpo Forestale dello Stato in the context of the LIFE Project LIFE04NAT/IT/000190 “Tutela dei siti NATURA 2000 gestiti dal Corpo Forestale dello Stato”.

BELLUNO

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MATERIALS AND METHODS

As described in the introductive article (Viola et al. 2008) on the geographic, climatic and historic as-pects, the Val Tovanella Nature Reserve is included in the Dolomitic system and it is an area dominated by forests. Primary grasslands, which are often grazed by wild ungulates, are present on the highest peaks, above the timberline and on rocks. The grasslands clearings that the LIFE Project (LIFE04NAT/IT/000190) aims to extend and to enhance are described in a different paper (Lasen & Scariot 2008). In this paper, we present an overview of the forest vegetation, its ecological characteristics and dynamics, mainly through the method of stand-level forest typology (sensu Del Favero 1992; Barbati et al.

1999; Del Favero 2000). This work helps to identify the natural potential vegetation, which should be the fi rst step when planning the management of a strict nature reserve, like Val Tovanella. Within the forest complex, we performed a detailed analysis of the vegetation types, the characteristics of which were used to assess the nature value of the reserve.Even though a detailed knowledge of the vegetation of the reserve and, in general, of the Dolomites was avail-able, the aim of our work was applicative and there-fore we did not consider the syntaxonomical aspects, because such an approach would have required a sam-pling intensity not compatible with the LIFE Project. Some phytosociological relevés have been carried out, but these did not allow compiling a table which would adequately describes the vegetation types treated.

Natura 2000 Habitats map, forest types and vegetation outline of Val Tovanella Nature Reserve

Cesare LASEN, Alberto SCARIOT, Tommaso SITZIA

ABSTRACT

The vegetation of Val Tovanella Nature Reserve was surveyed during the LIFE Project LIFE04NAT/IT/000190 to produce a map of Habitats of Community interest (Natura 2000 Habitats). The territory of the reserve is mostly occupied by forests, and a large number of forest types and their respective facies were recorded. Particularly important are Tilio-Acerion ravine forests, and black pine forests, which are Priority Habitat types. The forest cover includes wide silver fi r and beech forests, and the subalpine mountain pine woods, the latter being a Priority Habitat type as well. Pioneer vegetation of the rocky slopes and screes is well-represented. We present the list and a description of habitat types, which are essential for future management, and we also highlight the nature value of the vegetation, with regard to syntaxonomic features.

Key words: beechwoods, silver fi rwoods, mountain pine woods, Tilio-Acerion, vegetation, naturalness, Dolomites, Val Tovanella Nature Reserve.

RIASSUNTO ESTESO

Lo studio vegetazionale della Riserva di Val Tovanella nell’ambito del Progetto LIFE LIFE04NAT/IT/000190 è stato fi nalizzato essenzialmente al rilevamento cartografi co degli Habitat Natura 2000, con particolare attenzione verso quelli forestali. Allo scopo si è privilegiato un approccio tipologico-applicativo, rispetto a quello fi tosociologico classico, pur non trascurando di evidenziare problematiche di inquadramento sintassonomico. In mancanza di lavori precedenti, il presente studio costituisce la base per impostare programmi di monitoraggio e valutare le tendenze dinamiche in atto. Tra le unità cartografate emergono nettamente le faggete (con 9 unità e tre codici, che occupano circa 1/3 dell’intera superfi cie) e le mughete (codice prioritario Habitat 4070, con quattro unità e superfi cie complessivamente superiore al 26%), seguite dagli abieteti (due unità, associate al codice fagetale 9130, oltre il 18%). Gli ambienti primitivi, con rocce e ghiaioni, tipici del paesaggio dolomitico di alta quota, incidono per circa il 10%. La vegetazione della riserva è arricchita, sia pure con ridotto contributo percentuale, da formazioni particolari, alcune delle quali di interesse prioritario, come i boschi di forra del Tilio-Acerion (9180) o le pinete di pino nero (9530). A livello paesaggistico, inoltre, è interessante il contributo di formazioni subalpine mesoigrofi le con lembi di lariceti a megaforbie, faggete a megaforbie con larici, alnete di ontano verde e formazioni a Sorbus aucuparia che, nel complesso, superano il 5%. Trascurabile è l’incidenza delle formazioni erbacee (attestate intorno all’1%), al pari di quella delle formazioni secondarie. Va segnalato che il rilevamento cartografi co degli habitat, pur se condotto a scala di buon dettaglio (1:10 000), non consente di evidenziare adeguatamente i numerosi microhabitat (orli e radure boschive, piccole sorgenti, balze rupestri, nicchie sottoroccia, aree calpestate e ricoveri di animali) e i diversi stadi di transizione ed ecotonali. Per ogni categoria di habitat sono stati evidenziati gli aspetti di maggior valore naturalistico, la loro diffusione all’interno della riserva e le problematiche relative alla loro variabilità e al signifi cato sintassonomico.

RESEARCH ON THE NATURAL HERITAGE OF VINCHETO DI CELARDA AND VAL TOVANELLA (BELLUNO PROVINCE, ITALY) – QUADERNI CONSERVAZIONE HABITAT – 5/2008: 325-334.

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CESARE LASEN, ALBERTO SCARIOT, TOMMASO SITZIA

Fig. 1. Vegetation map with habitats of community interest of Val Tovanella Nature Reserve (surveys conducted in 2005-06). Legend: see map codes and colors in tab. 1 and fi g. 2. (Regione del Veneto, Carta Tecnica Regionale, Autorizzazione n. 686451/5700/1100 del 23.12.2008).

VAL TOVANELLA NATURE RESERVE

VEGETATION MAPWITH NATURA 2000 HABITATSSURVEYS CONDUCTED IN 2005-06

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The vegetation survey was based on a preliminary in-terpretation of the aerial photos of the It2000 fl ight, followed by fi eld surveys. For some areas, due to their scarce accessibility, we gave a synthetic evaluation of the vegetation cover based on the available scientifi c lit-erature on the vegetation of the Dolomites. The scarce accessibility was associated with a high level of natu-ralness, and the uneven topography was assumed to increase the number ecological micro-niches present.

State of knowledgeThe vegetation of the reserve had never been specifi -cally investigated before, however on a regional level forest types have been described by Del Favero & Lasen (1993), Del Favero (2000); for clearings and grasslands we followed the work by Ziliotto et al. (2004). The syntaxonomic references used here are: the monograph on vegetation of Austria (Grabherr & Mucina 1993; Mucina et al. 1993a, 1993b) and a pa-per on the vegetation series of Veneto region, (Buffa et al. in press). For silver fi rwoods and their classifi cation, a fundamental historical work is the book by Mayer (1969), with a contribution by A. Hoffman. Some synthetic reviews on the description and interpreta-tion of syntaxonomic units for the regions adjacent to Veneto were recently published: Gafta (1994), Poldini & Nardini (1994), Poldini & Bressan (2007). Norway spruce forests in the Dolomites were investigated by Lasen & Pignatti (2002). Beechwoods of specifi c areas were studied by several authors, but even the Euro-pean monograph by Willner (2002) does not describe the forests of the South-Eastern Alps. Scots and black pine woods were studied by Poldini (1969), De Mas et al. (1990), Poldini & Vidali (1999) and Minghetti (2003) who described also the relationships with the Fraxinus-Ostrya communities. Mountain pine woods were studied by Minghetti (1996) and Poldini et al. (2004).

RESULTS AND DISCUSSION

The vegetation map is presented in fi g. 1 and the leg-end in fi g. 2. The evident dominance of beech- and mountain pine woods (fi g. 3), followed by silver fi rwoods (which are associated to the beechwoods category also in the Natura 2000 Habitat classifi -cation) is an indication of the suboceanic climate. This interpretation is confi rmed by the lack of pri-mary Norway spruce forests. The biodiversity of Val Tovanella is enhanced by the important number of niche habitats, such as Tilio-Acerion ravine habitats and the dry rocky slopes with black pine (a Priority

NATURA 2000 HABITATS MAP, FOREST TYPES AND VEGETATION OUTLINE OF VAL TOVANELLA NATURE RESERVE

Fig. 2. Legend of fi g. 1.

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Habitat) and/or Scots pine, even if these habitats oc-cupy only a small surface area. The sub-hygrophilous upper-montane and subalpine formations rich in Al-nus alnobetula (Ehrh.) K. Koch, Larix decidua Mill., Sorbus aucuparia L. and hygrophilous tall herbs are very peculiar and expanding. Grasslands are probably under-represented compared with other parts of the Dolomites, covering slightly more than 1.6%, includ-ing nitrophilous fringe communities and transition habitats. Screes and rocky habitats cover around 10% of the landscape.

Beech- and silver fi rwoodsThe diversity of beech and silver fi rwood types is evi-dent from the list presented in tab. 1. Habitats related to calcareous soils are dominant and the ecological conditions for the development of acidophilous com-munities are very rare, due to the steepness of the slopes and the shallow soils, prone to runoff (fi g. 4). The percentage of species with Illyrian gravitation is negligible and thus, although most of the beechwoods (with the exception of the xerothermic ones, which can be attributed to Habitat 9150, the Cephalan-thero-Fagion) can be classifi ed as impoverished stages of Aremonio-Fagion (mainly to Anemono-Fagetum s.l., but also Ostryo-Fagetum in the submontane belt), they are ecologically closer to Habitat type 9130, ac-cording to the Interpretation Manual of Natura 2000 Habitats (European Commission 2007).The separation of the Illyrian and the Central-Euro-pean alliances in the Dolomites has not been resolved

yet. The upper-montane beech forests, especially those rich in tall herbs and bordering the areas of Al-netum viridis s.l. and Sorbus aucuparia communities (pioneer communities, favoured by the prolonged snow cover and by deer grazing), are often rich in Larix decidua Mill.; these woodlands can be classifi ed as Polysticho-Fagetum.In Costa de Bò and Còl Sirón, probably due to past logging, we mapped an evident area of mesophilic spruce-beechwood which can be distinguished from similar communities by the lack or scarcity of silver fi r. This formation could be a phase of alternation between the two main species and it seems to be an impoverished Anemono-Fagetum.A Natura 2000 code could not be attributed to a large percentage of beechwoods, mapped as primitive rupi-colous and scree beechwoods. These are located on cliffs and in ravines scarcely accessible, and should be investigated more accurately, as they contribute no-ticeably to the forest diversity at landscape scale. The silver fi rwoods, all included in the beech forest com-munities of calcareous substrate, are mostly represented by Dentario pentaphylli-Fagetum or Adenostylo glabrae-Abietetum (s.l.). The former (in Costa Signora, Còl de la Varda, and below Còl Sirón) have a strong beech com-ponent and its contact with ravine communities, due to the orography and morphology of the slopes, is shown by a higher percentage of Acer platanoides L. and, more rarely, of Ulmus glabra Huds. Compared with the mo-saic habitat with Tilio-Acerion communities, the silver fi rwoods lack the indicator species of the Tilio-Acerion

Fig. 3. Percentages of vegetation categories.

Vegetation categories

Primitive vegetation on screes and rocky habitats

9.81%

6.12%

Subhygrophile formations withFagus silvatica, Alnus viridis,

1.57%

5.17%

1.51% 1.22% 1.13%0.93%

0.15%

0.05%

26.79%

26.77%

18.78%

Sorbus aucuparia and Larix decidua

Nitrophilous vegetation and degraded clearings

Grasslands

Recent secondary woods

mountain pine scrubs

Beechwoods

Pinewoods Sprucewoods

Scree woodlands

Silver-firwoods

Ravine forests

Spruce-beechwoods

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Tab. 1. List of habitats mapped. The Habitat types and names (* : Priority Habitat) are simplifi ed and modifi ed from those of the Annex I of the Habitat Directive, which are listed and described in the Manual of European Union Habitats (European Commission 2007).

HABITAT NATURA 2000 Surface (ha) % Map code

FORESTS

9130 Asperulo-Fagetum beech forests

Calcareous silver fi rwoods 39.1 3.76 1

Suboceanic montane silver fi rwoods 156.28 15.02 2

Typical montane beechwoods 12.64 1.21 3

Suboceanic typical montane beechwoods 140.33 13.49 4

Mesic spruce-beechwoods 39.59 3.81 5

387.94 37.29

9140 Medio-European subalpine beechwoods with Acer and Rumex arifolius

Typical subalpine beechwoods variant with tall herbs 17.72 1.70 6

Typical subalpine beechwoods variant with larch 17.89 1.72 7

35.61 3.42

9150 Medio-European limestone beech forests of the Cephalanthero-Fagion

Submontane hop-hornbeam beechwoods 79.76 7.67 8

Xeric Spruce-beechwoods variant with larch 24.03 2.31 9

103.79 9.98

9530 * Esalpic Scots pine woods with black pine 8.77 0.84 10

MOSAIC OF WOOD HABITATS

9180 */ 9130 Suboceanic submontane silver fi rwoods 11.79 1.13 11

9420 / 9140 Larchwoods with tall herbs (with beech) 17.4 1.67 12

TEMPERATE HEATH AND SCRUB

4060 Alpine and Boreal heaths

Alpine green alder scrubs 0.25 0.02 13

European rowan woods 0.48 0.05 14

0.73 0.07

4070 * Bushes with Pinus mugo and Rhododendron hirsutum

Mesothermic mountain pine scrubs 48.16 4.63 15

Microthermic mountain pine scrubs on basic soils 131.79 12.67 16

Microthermic mountain pine scrubs on basic soils variant with larch 5.43 0.52 17

185.38 17.82

MOSAIC OF TEMPERATE HEATH AND SCRUB AND OTHER HABITAT TYPES

4070/8210 Microthermic mountain pine scrubs mixed with calcareous rocky slopes 93.17 8.96 18

NATURAL GRASSLANDS

6170 Alpine and subalpine calcareous grasslands

Calcareous grasslands 2.68 0.26 19

Primitive calcareous grasslands 6.62 0.64 20

6430 Mixed tall herb communities with Deschampsia 0.35 0.03 21

9.65 0.93

MOSAIC OF NATURAL GRASSLANDS AND OTHER HABITAT TYPES

6170/4060 Calcareous grasslands in evolution with green alder 6.12 0.59 22

PRIMITIVE VEGETATION ON SCREES AND ROCKY HABITATS

8120 Calcareous and calcshist screes of the montane to alpine levels

Screes in woodlands 1.18 0.11 23

Calcareous screes 44.34 4.26 24

45.52 4.38

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alliance in their herbaceous undergrowth. In fact, clear-ings with Atropion (which could not be mapped due to their small size) were present within the silver fi rwoods. The vegetation of the silver fi rwoods on calcareous sub-strate (Pescòl site) is characterized by indicator species of soils with varying moisture level (Adenostyles glabra (Mill.) DC., Carex alba Scop., Rubus saxatilis L., Sesleria caerulea (L.) Ard., Calamagrostis varia (Schrad.) Host and Carex austroalpina Bech.).

Mountain pine woodsMountain pine wood habitats are well represented, like in most of the Dolomites. The carbonatic and microthermic associations are the most common (mostly Sorbo chamaemespili-Pinetum mugo on the cool and slightly acid sides, and Rhododendro hirsuti-Pinetum prostratae in sites with less developed soil). In mountain pine woods on decalcifi ed soils the pres-ence of Rhododendron ferrugineum L. and various spe-cies of the genus Vaccinium is still considerable, while species of the Seslerietalia coeruleae decrease. A vegeta-tion type with an even stronger pioneer character is the subalpine Rhodothamno-Rhododendretum hirsuti

association located in high elevations, at the timber-line, bordering screes, on alluvium and colluvium. A grasslands unit with abundant larch was recorded above Sesaròla.The mesothermic mountain pine woods recorded at Còl Tamài, Còl Pelos, Costa Signora, do not show relevant phytosociological differences, even if they are typical of lower altitudinal belts. These woods can evolve, in the montane belt, into beechwoods. The succession of species frequently includes Sorbus aucuparia L. and Laburnum alpinum (Mill.) Bercht. & J. Presl, which can take advantage, together with the mountain pine, of the rockslides. However, the continuity of the succession is often hindered by the repeated deposition of debris.The mountain pine woods form mosaics with habi-tats such as screes, and often occupy scarcely accessible terraces on cliffs. These communities are stable over long periods; their evolution is often arrested by the extreme environment which limits soil maturation.

Norway spruce woodsAlthough Norway spruce is very abundant within

HABITAT NATURA 2000 Surface (ha) % Map code

8210 Calcareous rocky slopes with chasmophytic vegetation 50.13 4.82 25

MOSAIC OF PRIMITIVE VEGETATION ON SCREES AND ROCKY HABITATS AND OTHER HABITAT TYPES

8120/3220 River banks 6.42 0.62 26

TOTAL HABITAT NATURA 2000 962.41 92.51

OTHER NATURAL OR SEMI-NATURAL HABITATS

WOODS

Primitive rupicolous and scree beechwoods 45.93 4.41 27

Primitive rupicolous manna ash-hop hornbeamwoods 0.53 0.05 28

Secondary montane spruce woods 12.71 1.22 29

Esalpic Scots pine woods with beech 7.58 0.73 30

Primitive rupicolous larchwoods 9.10 0.87 31

Sycamore recent secondary woods 0.52 0.05 32

76.37 7.34

GRASSLANDS

Bracken communities 0.05 0.005 33

Brachypodium caespitosum degraded pastures 0.22 0.02 34

Degraded clearings (Agrostis tenuis and E. cyparissias) 0.45 0.04 35

Degraded clearings (B. caespitosum and E. cyparissias) 0.15 0.01 36

Nitrophilous communities (with Urtica dioica, Senecio cordatus) 0.22 0.02 37

Nitrophilous communities (with U. dioica, S. gaudinii) 0.10 0.01 38

Nitrophilous communities (with Mentha longifolia, Aconitum sp.) 0.38 0.04 39

1.57 0.15

TOTAL OTHER NATURAL OR SEMI-NATURAL HABITATS 77.94 7.49

TOTAL RESERVE 1 040.35 100.00

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Fig. 5. Black pine forests (Priority Habitat - 9530) at “Costa de Pin” (photo by A. Scariot).

Fig. 4. View of “Còl Sirón” and “Sesaròla”. A continuous forest cover characterizes the whole reserve (photo by A. Scariot).

the reserve, a well developed Norway spruce wood is not present. The few Norway spruce woods which can be identifi ed are in fact an early succession stage of old grasslands, (near old “casère”, such as at Pescòl), or are planted. Beech, fi r, and larch with their accompanying herbs and shrubs, are effi cient competitors, and characterize all the mature and natural forests.

Pine woodsTwo kinds of pine forests were recognized in Val Tovanella: with and without black pine. The woods with black pine belong to a Priority Habitat, they are located in “Costa del Pin” (the toponym already ex-presses the high naturalness of this forest) and repre-sent an esalpic penetration towards the inner part of the Dolomites (fi g. 5). Some sections are very beauti-ful, but very exposed, and typical of erodible areas with extreme ecological conditions.The species typical of the Erico-Pinetalia order pre-vail above those of the Fagatalia sylvaticae. The ther-mophilous component is scarcer than in the typical Fraxino orni-Pinetum nigrae association. Other small woods with black pine were identifi ed during the sur-veys, but they were too small to be mapped, thus con-fi rming that these communities are typical of extreme

topographical conditions. On the other hand, the typical esalpic montane Scots pine woods with beech, located in the eastern section of the reserve, below Casèra Tartana, are typical of steep and dry slopes. The constant presence of beech and its associated herbaceous species shows that these forests are most probably the result of strong exploitation occurred in the past centuries, which impoverished the soil.

LarchwoodsLarchwoods are often physiognomical, not climatog-enous, long-lasting successional stages, conditioned by various anthropic and natural factors (e.g. gorges exposed to snow-slides, grazing by wild ungulates, etc.). The most natural communities in Val Tovanella are the primitive ones, on inaccessible slopes, which cannot be classifi ed according to the Natura 2000 Habitats (other than as complex habitat mosaics). They could be attributed to the Rhodothamno-Larice-tum association, at least for their ecological character-istics. The most typical larchwoods in Val Tovanella (Sesaròla area and mostly Còl Sirón) are those where the trees occupy areas covered by long-lasting snow, with snow-slides and accumulation of nutrients. The tall herbs clearings (in particular Adenostylo-Cicerbite-tum communities, Aconitum sp. pl. communities and

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patches of Rumicion alpini alliance) are associated to Alnion viridis communities, often with abundant Sor-bus aucuparia L. These sites are located in the upper limit of the larch distribution and, in some cases, a variant upper montane/subalpine beechwoods with tall herbs can be identifi ed. The ecology of these com-munities is very interesting, and their phytosociology should be further investigated.

Ravine woodsIn the Val Tovanella ravine tree species of the Tilio-Acerion alliance are well represented, distributed over a good altitudinal range (from the bottom valley up to about 1 200 m a.s.l.). The herbaceous indicator species, on the other hand, seem less competitive, and more localized; the most important is Asplenium scolopendrium L., whereas Polystichum aculeatum (L.) Roth, Aruncus dioicus (Walter) Fernald, Actaea spicata L., Cardamine pentaphyllos (L.) Crantz, Aconitum degenii Gáyer subsp. paniculatum (Arcang.) Mucher and several ferns are differential species. It must be mentioned that several areas where this community was potentially present were inaccessible, and a more detailed survey than the one used for habitat map-ping should be carried out. Because Ravine woods are a Natura 2000 Priority Habitat, a more thorough investigation would be well justifi ed.

Other forest typesA small but interesting section of primitive rupicolous Fraxinus-Ostrya communities, with Amelanchier ovalis Medik. and Genista radiata (L.) Scop. as guide species (possibly categorizable as Cytisantho-Ostryetum asso-ciation) was recorded on the sunny slopes in the outer section of the valley. A clearing in Costa Signora has been colonized by well-developed secondary woods dominated by Acer pseudoplatanus L.

Other shrublandsWe recorded, apart from the various types of moun-tain pine bushes, Alnetum viridis s.l. and Sorbus au-cuparia L. heaths (already mentioned in the paragraph on beechwoods).

GrasslandsThe areas covered by grasslands and pastures are small. The typical Seslerio-Caricetum sempervirentis associa-tion, found above Sesaròla pastures, in small patches not easily recognisable, actually seems to belong to a Calamagrostion variae community subject to strong runoff where, due to the abandonment of pasture (al-though grazing by wild ungulates is still important),

Caricion ferrugineae s.l. and pre-nemoral species are increasing in abundance. A mosaic of Ranunculo hybridi-Caricetum smperviren-tis and Gentiano terglouensis-Caricetum fi rmae associa-tions is widespread in the rare grasslands of higher el-evation, between Noni and Rocchetta. Fragments of the same associations (6.62 ha in total) are often (but usually on small surfaces) located near block screes, in some cases being consolidated with bushes of Pi-nus mugo Turra (i.e. below Rocchetta). Also in this case the evolution of this association is likely to take a long time.The species typical of Seslerietalia (see above) are associated with elements belonging to Erico-Pineta-lia and, mostly, of Thlaspietalia orders. Sections of Festucetum alpestris, with a variant attributable to Festuco-Brometea poor in thermophilous species and therefore classifi ed as Habitat 6170 (e.g. between Noni and Costa de Bò) are present in sites which are diffi cult to access, on steep sunny slopes at the base of cliffs.A degraded habitat dominated by Deschampsia cespi-tosa (L.) P. Beauv. exists in Sesaròla and Còl Fasòn, as well as an edge of Nardion and Calamagrostis villosa communities (too small to be mapped).

Primitive vegetation on screes and rocky habitatsTaking into account the applicative scope of the LIFE Projects, the pioneer communities of screes and rocky habitats were mapped but not specifi cally investigated, because they are scarcely vulnerable and do not differ from the communities which are well-known for the Dolomites area. The presence of patches of communities typical of stream banks in some canyons was particularly interesting. Petasites paradoxus (Retz) Baumg, Tolpis staticifolia (All.) Sch. Bip., Salix eleagnos Scop., Salix purpurea L. were the guide species. Vegetation of screes and colluvial sites includes sev-eral communities, such as Papaveretum rhaetici, Atha-manto-Trisetetum argentei, Festuca pulchella subsp. jurana communities, Adenostyles glabra communities and other communities belonging to Petasition para-doxi alliance.The chasmophytic vegetation has a high value of naturalness; it was represented by the alliances An-drosaco-Drabion (Spiraeo-Potentilletum caulescentis, Campanuletum morettianae, Potentilletum nitidae communities) and Cystopteridion (Valeriano elonga-tae-Asplenietum viridis, Carex brachystachys commu-nities). The syntaxonomical position of the site rich in the endemic Moehringia glaucovirens Bertol. needs to be further investigated.

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REFERENCES

Barbati A., Carraio G., Corona P., Del Bavero R., Dissegna M., Lasen C. & Marchetti M., 1999. Developing biodiversity assessment on

a stand forest type management level in North-Eastern Italy. BEAR Technical Report 5. Available from http://www.algonet.se/~bear/

Buffa G., Gamper U., Lasen C., Mion D. & Sburlino G., (in press). Carta delle serie di vegetazione del Veneto, scala 1: 250.000.

Del Favero R., 1992. Un’esperienza di studio di tipologia forestale. Annali dell’Accademia italiana di Scienze Forestali, 41: 65–84.

Del Favero R. (ed.), 2000. Biodiversità e Indicatori nei tipi forestali del Veneto. Commissione Europea, Regione Veneto e Accademia

Italiana di Scienze Forestali, Venezia Mestre, 335 pp.

Del Favero R. & Lasen C., 1993. La vegetazione forestale del Veneto. II Edizione. Libreria Progetto, Padova, 313 pp.

De Mas G., Lasen C. & Poldini L., 1990. Einige Betrachtungen zu den Föhrenwäldern (Pinus sylvestris L.) im Veneto, pp. 59–70. In:

Szabo I. (ed.), Illyrische Einstrahlungen im Ostalpin-Dinarischen Raum. Sym posium in Keszthely 25-29 Juni 1990.

European Commission 2007. Interpretation manual of European Union habitats. Eur 27. European Commission, DG Environment,

Strasbourg, 142 pp. Available from http://ec.europa.eu/environment/nature/legislation/habitatsdirective/docs/2007_07_im.pdf

Gafta D., 1994. Tipologia, sinecologia e sincorologia delle abetine nelle Alpi del Trentino. Braun-Blanquetia, 12: 1–69.

Grabherr G. & Mucina L. (eds.), 1993. Die Pfl anzengesellschaften Österreichs, Teil 2: Natürliche waldfreie Vegetation. Gustav Fischer

Verlag, Jena, 523 pp.

Lasen C. & Pignatti S., 2002. Spruce forests of the Dolomites and related areas of the South-Eastern Alps. Ecology, management and

syntaxonomy. Razprave IV. Razreda SAZU, XLIII-3: 267–282.

Lasen C. & Scariot A., 2008. Experimental plots and phytosociological relevés in grassland clearings currently under restoration in Val

Tovanella, pp. 235-348. In: Hardersen S., Mason F., Viola F., Campedel D., Lasen C. & Cassol M. (eds.), Research on the natural

heritage of the reserves Vincheto di Celarda and Val Tovanella (Belluno province, Italy). Conservation of two protected areas in the

context of a LIFE Project. Quaderni Conservazione Habitat, 5. Arti Grafi che Fiorini, Verona.

Mayer H., 1969. Tannenreiche Wälder an Südabfall der Mittleren Ostalpen. BLV Verlagsgesellschaft, München, 259 pp.

Minghetti P., 1996. Analisi fi tosociologica delle pinete a Pinus mugo Turra del Trentino (Italia). Documents phytosociologiques, 16:

461–503.

Minghetti P., 2003. Le pinete a Pinus sylvestris del Trentino-Alto Adige (Alpi Italiane): tipologia, ecologia e corologia. Braun-Blanquetia,

33: 1–95.

Mucina L., Grabherr G.& Ellmauer T. (eds.), 1993a. Die Pfl anzengesellschaften Österreichs. Teil 1: Anthropogene Vegetation. Gustav

Fischer Verlag, Jena, 578 pp.

Mucina L., Grabherr G. & Wallnöfer S. (eds.), 1993b. Die Pfl anzengesellschaften Österreichs, Teil 3: Wälder und Gebüsche. Gustav

Fischer Verlag, Jena, 353 pp.

Poldini L., 1969. Le pinete di pino austriaco nelle Alpi Carniche. Bollettino della Società Adriatica di Scienze, 57: 3–65.

Poldini L. & Bressan E., 2007. I boschi ad abete rosso ed abete bianco in Friuli (Italia nord-orientale). Fitosociologia, 44 (2): 15–54.

Poldini L.& Nardini S., 1994. Boschi di forra, faggete e abieteti in Friuli (NE Italia). Studia geobotanica, 13: 215–298.

Poldini L., Oriolo G. & Francescato C., 2004. Mountain pine scrubs and heaths with Ericaceae in the south-eastern Alps. Plant Biosy-

stems, 138 (1): 53–85.

Poldini L. & Vidali M., 1999. Kombinationsspiele unter Schwarzföhre, Weißkiefer, Hopfenbuche und Mannaesche in den Südostalpen.

Wissenschaftliche Mitteilungen aus dem niederösterreichischen Landesmuseum, 12: 105–136.

CONCLUSIONS

Val Tovanella Nature Riserve is covered almost every-where by woodlands, except in the higher altitudes where primary grasslands and pioneer communities of rocks and screes are present. The vegetation analysis confi rmed the suboceanic character of Val Tovanella, where beechwoods are dominant (or fi rwoods de-pending on topographic aspects and soil depth). A primary spruce wood belt, between high-montane beechwoods and mountain pine woods, is absent. On the cooler and wetter slopes, which are prone to

snow-slides, larchwoods with green alder and rowan are present. In contrast, the sunny and rocky slopes are occupied by Scots pine and black pine woods. Even if the process of renaturalization is still ongo-ing, signs of the heavy logging, which occurred in the past, are still visible. Finally, the ravine habitats with broadleaves species (Tilio-Acerion s.l.) are noteworthy because of their high nature value. We recommend investigating the syntaxonomical aspects of the valley in more detail in the future, also through the esta-blishment of permanent plots.

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Viola F., Campedel D. & Toffolet L., 2008. Introduction, pp. 17-24. In: Hardersen S., Mason F., Viola F., Campedel D., Lasen C. & Cas-

sol M. (eds.), Research on the natural heritage of the reserves Vincheto di Celarda and Val Tovanella (Belluno province, Italy). Conser-

vation of two protected areas in the context of a LIFE Project. Quaderni Conservazione Habitat, 5. Arti Grafi che Fiorini, Verona.

Willner W., 2002. Syntaxonomische Revision der südmitteleuropäischen Buchenwälder. Phytocoenologia, 32 (3): 337–453.

Ziliotto U., Andrich O., Lasen C. & Ramanzin M., 2004. Tratti essenziali della tipologia veneta dei pascoli di monte e dintorni. Regione

del Veneto, Accademia Italiana di Scienze Forestali, Venezia, 208 pp. (Vol 1), 264 pp. (Vol. 2).

Addresses

CESARE LASEN

Via Mutten, 27 • I-32032 Arson di Feltre (BL)

<[email protected]>

ALBERTO SCARIOT

Via Busette di Fianema, 1 • I-32030 Soranzen Cesiomaggiore (BL)

<[email protected]>

TOMMASO SITZIA

Dipartimento Territorio e Sistemi Agro-forestali, Università degli Studi di Padova

Viale dell’Università, 16 • I-35020 Legnaro (PD)

<[email protected]>
