Estrutura e composição da comunidade de tricladidos em áreas com alto grau de impacto antrópico do sul do Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Land planarians are bioindicators of the degree of anthropization and preservation of their habitats and areas of high general biodiversity. Some species which occur in Rio Grande do Sul could be used as bioindicators of preserved or altered areas, but the studies have been restricted to legally protected areas showing relatively large fragments of native forest. This paper aims at analysing the structure and composition of land planarian community in areas of secondary forests and grassland of the Universidade do Vale do Rio dos Sinos Campus - UNISINOS, in São Leopoldo, RS along an annual cycle. Four areas of secondary forest and four grassland areas were selected, where 12 samplings were carried out. For each area two 100m-long transects had their boundaries set, where ten points along each transect were randomly chosen. At each point a 4m plot was used, with a 10-minute sampling effort. 78 specimens were recorded, which belong to nine species of two Terricola families (Geoplanidae e Rhynchodemidae). Only one species, Notogynaphallia abundans (GRAFF, 1899), was recorded in both types of habitats; the other species were recorded only in the forest fragments. Comparing the richness of the forest fragment and the grassland areas, the highest values were recorded in the forest fragment (ANOVA, F=8,000; gl=1,6; p<0,05). Regarding abundance and diversity, there was no significant difference between forest and grassland areas. The analysis of how the richness and the abundance of land planarians are allotted among the seasons of the year in areas of forest and gardens at the UNISINOS Campus shows no significant differences. Differing from studies carried out in ombrophilous forest located in preservation areas, which show great extension and structurally high complex vegetation, the UNISINOS Campus is characterized as an environment with a high degree of human impact, including constant building enlargements. By considering those characteristics of the study area, the Terricola richness can be considered as high. The results point to the need to preserve the largest possible extension of the fragments of seasonal forest in that area, thus providing the appropriate conditions to maintain the species richness

ASSUNTO(S)

triclads àreas antropizadas biologia geral terricola community ecology tricladidos anthropized areas terricola ecologia de comunidades

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