Edge effect in spider guilds in a continuous forest of Central Amazonia.

FLORENCIA FERNÁNDEZ CAMPÓN

Canterburry, UK

Congreso; Society of Conservation Biology Meeting; 2002

In this study, the edge effect on abundance of two spider guilds was examined. These guilds involved "sit and wait" (Thomisidae, n=51) and "ambush" (Salticidae, n=78) spiders. The edge effect was produced by a road crossing continuous forest in Central Amazon, 80 km north from Manaus, Brazil. Four transects with sampling bands (2m x 20m) at 0, 15, 30, 70, 150, and 300 m from the edge of the road were sampled using the beating method to catch the spiders found in the vegetation. Each band had five quadrats every 4 m that consisted of a circular area of 1,5m in diameter within which vegetation was sampled. The edge effect was noticeable for total abundance as well as for each individual guild. However, the pattern showed by each guild was different, presenting abundance peaks at 15m for thomisids and at 15m and 70m for salticids. In the latter case, the second peak was much more important. Even when both guilds are affected by the edge, they responded idiosyncratically possibly due to differences in requirements such as prey distribution, microhabitat characteristics.