Variações estruturais de troncos mortos e tempestades de vento afetam a diversidade de passalídeos (Scarabaeoidea, Passalidae) na Amazônia Central?

Abstract

The amount of dead wood is one of the main predictors for the diversity of saproxylic beetles in forests. The understanding of how variations in dead wood and natural disturbances affect insect diversity is of extreme importance in understanding the forest dynamics, conservation and distribution of species. Thus, this dissertation was divided in two chapters, the first one sought to correlate the diversity of passalids with structural variations of the dead trunks (microhabitat), where they were correlated the abundance and composition of passalid beetles with diameter and between the decomposition classes of the trunks, as well as, we propose a classification for the species according to the region used for the construction of the galleries. In the second chapter we compared the richness, abundance and composition of passalid beetles between areas affected by windstorms (blowdown) and adjacent forest and between the size of the sampled areas, both studies in the state of Amazonas, Brazil. Multiple generalized models (GLM) were used to investigate the relationships between predictors and richness, abundance, and MANOVA by permutation for composition. The approaches indicate that the high variability of trunks used by the passalids in Campinaranas can mean a strong selection of species with generalist abilities, probably to compensate for the low dispersion and isolation in areas with low supply of resources in the Amazon. In the areas affected by blowdown were found greater riches and species abundances and surprisingly the size of the disturbed area had an inverse proportional effect on riches and abundance. Thus, blowdown can modify the way these species distribute in tropical forests. These results confirm the importance of dead wood structurants and natural disturbances in the diversity of saproxylic insects in Amazonia.