Beetles in bamboo forests: Diversity patterns in a heterogeneous landscape of southwestern Amazonia

Bamboo stands form a specific forest type in southwestern Amazonia and a number of vertebrates are known to be associated with this particular habitat. This study compared the structure of terrestrial beetle communities in bamboo patches and adjacent terra firme forest at the Los Amigos Conservation Concession in southeastern Peru. Beetle diversity patterns in bamboo and terra firme habitats were compared by examining composition, abundance, and richness at the species level. Beetles from four families were examined: Scarabaeidae, Carabidae, Histeridae, and Curculionidae. Thirteen patches of bamboo forest, with sizes ranging from approximately 1 to 25 hectares, and located at various distances from each other, were proportionally sampled with pitfall traps. A methodologically identical sampling procedure was performed in terra firme forest adjacent to each bamboo patch. A total of 632 pitfall trap samples were taken and approximately 4,000 individuals representing more than 100 species were collected, during both wet and dry seasons. Results indicate that terra firme forest was only slightly more species-rich than bamboo forest but had a substantially higher abundance of individuals. Species composition shifted during the wet and dry seasons for both forest types. The bamboo patches and adjacent terra firme forest shared approximately half of the documented species though many species were found only in one habitat. The results of this study support the assumption that habitat heterogeneity is important for maintaining species diversity at the local scale.