Taxonomic and functional diversity of epigeal spiders (Araneae) in native forest of the Yungas (Salta, Argentina)

Abstract

The study of the arachnofauna in the argentinean Yungas is scarce. However, it is relevant due to the high environmental and biological diversity, mainly in the forest systems threatened by the advance of the agricultural frontier. The aim of this work is to compare the diversity and composition of epigeal spider assemblages in the Piedmont Forest (SP), Mountain Jungle (SM) and Mountain Forest (BM) of the Yungas in the province of Salta. Three sites of the SP and BM, and five of the SM were considered. Sampling was carried out during autumn, spring (2006) and summer (2007) with pitfall traps. A total of 643 spiders of 75 species/morphospecies were collected. The SP sites showed the highest species richness and species composition very dissimilar compared to the SM and BM. The space web weavers, other hunters and ground hunters accounted for more than 95 % of the abundance in each community considered. They showed similar patterns of abundance in SM and BM, while in SP the space web weavers markedly reduced their abundance. The change in the landscape configuration due to the land use is the main forces that would be structuring the local assemblages of the SP. This study is the first to analyze the epigeal spiders diversity and their guilds in the Yungas of the argentine north, being a starting point for future monitoring of biodiversity in the region.

Keywords

• Araneofauna
• ecoregión
• ensambles de especies
• gremios
• uso del suelo