Effects of environmental parameters on beetle assemblage in a fragmented tropical rainforest of South America

Abstract

As a result of habitat fragmentation, the environmental structures of forest remnants change and alter their microclimatic conditions. Edaphic beetles comprise several families that are considered effective bioindicators. In this study, we analyzed how environmental parameters and fragment size affect edaphic beetle assemblage in a fragmented rainforest landscape in Brazil. Beetles were sampled in 12 forest fragments using pitfall traps. Fragment size, tree density and diameter, litter depth and dry weight, and canopy cover were measured in each forest fragment. Staphylinidae and Carabidae were the beetle families with the highest species richness, whereas Scarabaeidae and Nitidulidae were the most abundant families. Beetle abundance was positively affected by litter dry weight and fragment size. In addition, species composition was significantly affected by fragment area. In conclusion, forest patch size is an important parameter for maintaining edaphic beetle assemblages in tropical rainforests, causing major shifts in its abundance and species distribution.