Comunidade de Chrysomelidae (Coleoptera) de remanescentes florestais de Dourados, MS: composição de espécies, relação com a estrutura do habitat e diversidade beta

Abstract

To understand how the Chrysomelidae (Coleoptera) community works at local and regional scale, we made collections in 16 forest remnants in Dourados city, MS, Brazil, from August 2012 to March 2013. The region has remnants of Semideciduous Alluvial Forest and Cerrado, distributed in a landscape dominated by agriculture and planted pasture. At local scale we first conducted a study where the goal was to understand the relationship of these insects with habitat structure. We measured three variables to characterize each collection site: understory heterogeneity, canopy height and canopy cover. These variables significantly explained the variation of Chrysomelidae community data, which responded positively to the increase in heterogeneity of understory and canopy height, and negatively to the increase in canopy cover. We conclude that these facts are due to an increase in the abundance and diversity of host plants of these insects in areas where the canopy is the highest and there is a lower percentage of coverage. Thus, there is an increase in brightness, allowing native plants as herbaceous and shrub to develop, increasing the supply of resources to chrysomelids. On a regional scale, we seek to understand the process that determines the beta diversity of these beetles in fragmented landscapes, as well as whether the beta diversity is spatially structured. The determinant beta diversity process was attributed almost exclusively to species replacement (turnover) and did not show a spatial structure. We believe that, being insects dependent on their hosts, chrysomelid beta diversity can be explained by the distribution of them, although we do not find evidence of a distributional plant spatial pattern.