Summer Variations of the Morphology and the Pionner Vegetation of the Foredunein the Santinho Beach, Santa Catarina Island, SC, Brazil

INTRODUCTION

Oceanic sandy beaches are transitional environments

extremely dynamic, being constantly adjusted by the

fluctuations of local energy levels, experiencing modifications

by hydraulic, wind and biological processes ( , 1995).The coastal dunes form at the rearguard of sandy beaches and

its extension is related to the magnitude of sediment supply.

Dunes, among many other ecosystems, have been suffering

great antrophic pressure in many parts of the world.Only at the last 30 years they have being studied objectively

and the results applied to management practices

1988).Foredunes represent the interface between the beach

environment and the interior dunes. They are common features

of sandy beaches and receive a continuous supply of sand,

transported by dominant winds. They play an important role in

maintaining and preservation of the integrity of the coast

morphology, acting as dynamic barriers against wave action

and storm surges and 1995). The

formation of the dune ramp (slope) and the beach morphology

depend on the density and distribution of plants, the sand

volume, the wind velocity and the morphology of species

1989). On the other hand, cycles of erosion and accretion

of sand are determinant by the population dynamics of pioneer

species; hence, the monitoring of this vegetation is of relevant

importance to the monitoring of the coastline

2003).In the last decade, the Santa Catarina Island was intensively

affected by events of coastal erosion but few studies evaluated

in an integrated approach the geomorphological and vegetation

changes. The purpose of this study is to improve this integrative

field of research evaluating the dynamics of the pioneer

vegetation and changes at the foredune and beach morphology

at Santinho Beach, Santa Catarina Island.

Santinho beach, situated at the northeast coast of the Santa

Catarina Island (Figure 1), was monitored between November

2002 and March, 2003. Topographic profiles perpendicular to

the coast were realized at the south, central and north sectors of

the beach. Each profile extended from the reverse of the frontal

dune to the backshore using the leveling method

1985).The vegetation was sampled along the profile at December

2002 and March 2003, early and late summer, respectively. At

each sampling the vegetation cover was surveyed and the width

of the zone with vegetation measured. The vegetation cover was

determined by the point quadract method, which is based on the

vertical projection of a pin (1m high and 5mm thick) over a

point of the surface, registering at each point the species

intercepted by the pin and 1990). At

every 2m along the profile, 40 points were sampled, 20 to the

left and 20 to the right of the profile, distancing up to 1m of the

profile. Based on the total points sampled, the percentage of the

total vegetation cover (PCt) and of each species present (PCi)

was calculated for each profile.

PCt = x 100

Total of points sampled

PCi = x 100

Total of points sampled

HOEFEL

(CARTER,

(CORDAZZO SEELIGER,

(HESP,

(CASTELLANI,

(BIRKMEIER,

(MANTOVANI MARTINS,

METHODS

Total of points intercepted by at least one specie

Total of points intercepted by the specie

Journal of Coastal Research SI 39 622 - 625 ICS 2004 (Proceedings) Brazil ISSN 0749-0208

J. R. V. Peixoto †; N. O. Horn Filho‡; T.T. Castellani and U. R. de Oliveira†

† Programa de Pós-Graduação emGeografia, Universidade Federalde Santa Catarina, Florianópolis,SC, tartbr@yahoo.com.br,ulisseslicke@yahoo.com.br

PEIXOTO, J. R. V; HORN FILHO, N. O; T. T. CASTELLANI and OLIVEIRA, U. R. de, 2006. .Summer variations

of the morphology and pionner vegetation of the foredune in the Santinho beach, Santa Catarina island, SC, Brazil.

Journal of Coastal Research, SI 39 (Proccendigs of the 8th International Coastal Symposium), 622 - 625. Itajaí, SC,

Brazil, ISSN 0749-0208.

The aim of the study is improve the knowledge about the coastal environment in particularly the interaction between

the pioneer vegetation, the foredune and the beach environment. The Santinho beach is situated at the east side of the

Santa Catarina Island. Three topography profiles perpendiculars to the actual coastline were s ong the shore in

south, central and north sectors of the beach. These profiles were monitored from November 2002 to March 2003

from the lee foredune depression until the foreshore. The survey of the vegetation was realized in spring and summer

employing the point quadract method to quantify vegetation cover. The spring profiles showed smaller sediment

volume and smaller vegetation cover. In the summer, accretion occurred on the subaereal part of the beach increasing

in approximately 10m the width of the beach promoting the expansion of the vegetation toward the backshore. The

greatest vegetation expansion observed at the north sector is, probably, related to the high supply of sediment leaving

the slope of the foredune base.Atotal of 25 plant species were registered, being the south sector of lower richness.At

the summer, 17 species increased in vegetation cover but the ones, which expanded toward the beach, were

, and . At Santinho

beach the more protected portion of the beach presented profile more plain, greater percentage cover of arbustive

species and low richness.

et al

Panicum

racemosum, Paspalum vaginatum Ipomoea imperati, Remiria maritima Senecio crassiflorus

Pionner vegetation, foredune, sand beach.ADDITIONALINDEX WORDS:

ABSTRACT

‡ Departamento de Geociências,Universidade Federal de Santa Catarina,Florianópolis, SC, Brasil,horn@cfh.ufsc.

Departamento de Ecologia e

Zoologia, Universidade Federal deSanta Catarina, Florianópolis, SC, Brasil,ttcastel@ccb.ufsc.br

Journal of Coastal Research Special Issue 39, 2006,

Journal of Coastal Research Special Issue 39, 2006,

Interaction Pionner Vegetation-Dune-Beach

Figure 1. Map of study area, Santinho beach, Santa Catarina Island, Brazil.

623

RESULTS

DISCUSSION

The south sector, the most sheltered of the Santinho beach,showed a planer profile with incipient dune ridge. The centraland north sectors, more exposed to incident waves, showedscarps at the foredune and higher slopes (Figure 2).At the earlysummer profiles, the beach was flatter at all sectors, showing apercentage of total cover (PCt) of 57.1%, 65.0% and 76.2% atthe south, central and north sectors, respectively. The latesummer profiles were characterized by higher deposition at thebeach causing an increase of approximately 10m of the beachwidth.

At the south sector, a small depression was formed at thesuperior portion of the backshore, where patches of up to 6m ofextension of the graminea wereestablished. At this sector, the vegetation cover increased to62.5%, despite the impacts due to trampling (Figure 2A). At thecentral sector considerable accretion occurred at the berm,where the zone of vegetation expanded 2m at the superiorportion of the backshore and the vegetation cover increased to86.0% (Figure 2B). At the north sector, the backshore had ahigher supply of sediment from the base of the dune up to theforeshore (Figure 2C).

The vegetation zone expanded 4m in the backshore directionand the cover increased to 79.6%. The greatest expansion of thevegetation zone occurred at this sector, which also showed thegreatest sediment supply, leaving the slope of the foredune baseflatter.

A total of 25 species were recorded, being the south sectorwith the least species richness. At this sector, there is a denseoccupation of the shrub , whichadvances near the embryonic dune. Below its canopy, onlyoccurred and ,very sparse.

At late summer, 17 species increased their vegetation coverand 8 decreased or maintained stable (Table 1). Among thespecies that showed greatest expansionshowed an increase at all sectors and ,

, and cf.increased at the central and north sectors.

At the south sector, the expansion ofincreased the volume of the embryonic dune. Among thespecies sampled at late summer, the ones that effectivelyshowed expansion in the backshore direction were

at the south sector, ,and at the central sector, and

at the north sector.

The plainest profile registered at the south sector of theSantinho beach, where the shrubadvanced over the backshore, could be associated to the lowerenergy level at this region. The presence of the Aranhas Islandsprotects this sector from S-SE waves, the ones with highestenergy that reach the southern coast Brazil. On the other hand,the central and north sectors are more exposed to the incidentwaves, showing scarps at the foredune, higher slope and aforedune established by a higher number of species (Table 1).According to and (1994), it is suggested thatsheltered sectors favor the colonization of shrub species,decreasing, in part, the occurrence of the herbaceous species,better succeeded in areas with higher dynamism.

The increase of vegetation cover by dune species at the latesummer period could be, in part, related to the increase oftemperature at this period, since temperature is positivelycorrelated to the dune plant growth and1989, 2003). At this period there also occurred agreater sand deposition at the beach, which increased theavailability of habitats and favored colonization andestablishment of foredune species, and an expansion ofvegetation over the backshore. This agrees with (2000),who showed that for periods of low wave energy there isformation of embryonic dunes and stable foredunes and highervegetation growing. In periods of higher energy, the sedimentof the embryonic dunes and the face of the stabilized dunes areremoved by wave action, generating erosive profiles withforedune scarps, lower vegetation growth and even absence ofvegetation cover 2000). Even though most species

Paspalum vaginatum

Dalbergia ecastophyllum

Hydrocotyle bonariensis Panicum racemosum

Panicum racemosumRemirea maritma

Ipomoea pes-caprae Ipomoea imperati Eragrostislungens

Acicarpha spathulata

Paspalumvaginatum, Ipomoea imperati Remireamaritime Senecio crassiflorus,Panicum racemosum,

Dalbergia ecastrophyllum

,

WISHEU KEDDY

(BERNARDI SEELIGER,CASTELLANI,

HESP

(HESP,

Peixoto et al.

Journal of Coastal Research Special Issue 39, 2006,

624

Table 1. Porcentage the vegetable coverage for each specie (PCi) present the south sector (profile 1), central (profile 2) e north (profile

3) in Santinho beach during spring (SPR) and summer (SUM).

Profile 1 Profile 2 Profile 3

SPR SUM SPR SUM SPR SUM

Acicarpha spathulata 7.9 10.0

Androtrichum trigynum 0.8 0.5

Asclepias mellodora 0.8 0.2

Baccharis radicans - 0.1

Blutaparon portulacoides 8.3 9.5

Cardionema ramosissima 0.8 -

Cenchrus incertus 9.0 11.8 8.3 9.4

Chloris retusa - 0.7 - 2.5

Conyza canadensis 0.2 0.4

Cyperus obtusatus. - 0.5 - 0.1

Dalbergia ecastophyllum 16.6 26.0

Eragrostis .cf lugens 1.5 10.5 - 2.5

Hydrocotyle bonariensis 7.5 6.5 0.5 -

Ipomoea imperati - 2.0 1.5 11.6 1.1 1.6

Ipomoea pes-caprae 3.8 9.5 5.3 9.7

Noticastrum malmei 2.8 3.6 6.6 6.9

Oenothera mollissima 0.3 0.5

Oxypetalum .cf banksii 2.8 2.5 0.5 0.3

Panicum racemosum 3.3 9.5 37.3 38.4 47.0 52.5

Paspalum vaginatum - 15.5

Petunia littoralis 0.3 -

Polygala cyparissias 6.0 2.3 2.6 2.6

Porophyllum ruderale - 0.5 0.7 0.6

Remirea maritima 13.3 20.5 4.5 7.0

Senecio crassiflorus 1.3 - 0.8 2.3 - 1.5

Figure 2. Beach profiles in Santinho beach showed the sectors south (A), central (B) and north (C) during November/December 2000 andMarch 2003.

Interaction Pionner Vegetation-Dune-Beach

Journal of Coastal Research Special Issue 39, 2006,

625

showe

H. and U., 1989. Population biology of(St. Hill) Mears on southern

Brazilian backshores. , 41(11), 1110-1113.W.A., 1985.

Instructions ReportSeries. U. S. Army Engineer Waterwais Experiment Station.Vicksburg, Mississipi, Coastal Engineering ResearshCenter, 84p.

R.W.G., 1988.

London,Academic Press. 617p.T.T., 2003. Estrutura e dinâmica populacional de

(L.) R. Brown (Convolvulaceae) na

Ilha de Santa Catarina. Campinas, São Paulo: UniversidadeEstadual de Campinas, Tese de Doutorado, 206p.

C.V. & U., Ed. FURG, Rio Grande.

275p. 1995.C.S.B; U. and C.V., 1991. Leaf

demography and decline ofpopulations in coastal foredunes of southern Brazil.

69, 1593-1599.P.A., 1989. Review of biological and geomorphologica1

process involved in the inititation and development ofincipient foredune. , 96, 181-200.

P.A., 2000. .CDVN Technical Bulletin n.4.

F. G., 1995.. Monografia, FURG, Rio Grande. 71p.

W. and F.R , 1990. O método depontos. , 4 (2), 95-122.

J., 1978. Contribuição ao conhecimento davegetação e de suas condições de crescimento nas dunascosteiras do Rio Grande do Sul Brasil.

, 38(4), 827-836.C.R.; T.T. and N.O. 1996.

“Pioneer” vegetation dynamics at the beach and fore dunesin Joaquina beach, Santa Catarina Island, Brazil.

, 68(3), 495-508.I.C. and P.A., 1994. The low competitive

ability of Canada's atlantic coastal plain shoreline flora:implications for conservation. ,68:247-252.

d an increase of vegetation cover at this period, not allexpanded up to the backshore. At this colonization, the speciesthat showed the most relevant colonization are:

, , ,and . Most of these show

stoloniferous or rizomatous habits, favoring colonization byvegetative growing. and

were cited as the species that expanded the mosttowards the backshore in period of accretion at Joaquina Beach,Santa Catarina Island ., 1996), being

one of the most important species responsible fordune building at Brazilian southern coast ( 1978,

., 1991).

Panicumracemosum Paspalum vaginatum Ipomoea imperati Remireamaritima Senecio crassiforus

Panicum racemosum Paspalumvaginatum

et al Panicumracemosum

et al

(SANTOS

PFADENHAUER

COSTA

LITERATURE CITED

BERNARDI, SEELIGER,

BIRKMEIER,

CARTER,

CASTELLANI,

CORDAZZO, SEELIGER,

COSTA, SEELIGER, CORDAZZO,

HESP,

HESP,

HOEFEL,

MANTOVANI, MARTINS,

PFADENHAUER,

SANTOS, CASTELLANI, HORN FILHO,

WISHEU, KEDDY,

Blutaparon portulacoidesCiência e Cultura

A User's Guide to ISRPN: TheInteractive Survey Reduction Program.

Coastal Environments: An introductionto the Physical, Ecological and Cultural System ofCoastlines.

Ipomoea pes-caprae

Guia ilustrado da vegetaçãocosteira no extremo sul do Brasil

Panicum racemosum

Canadian Journal of Botany,

Royal Society of Edimburges

Coastal sand dunes: form and function

Morfodinâmica de praias arenosas: umarevisão bibliográfica

.Acta Botanica Brasilica

Revista Brasileira deBiologia

Anais daAcademia Brasileira de Ciências

Biological conservation