Exotic pastureland is better than Eucalyptus monoculture: β-diversity responses of flower chafer beetles to Brazilian Atlantic Forest conversion

Abstract

Human activities, such as conversion and degradation of habitats, are modifying the natural ecosystems, causing biodiversity declines globally. However, the responses of many understudied biological groups are less clear. Here, we explore how spatial components of β-diversity (incidence- and abundance-based) of flower chafer beetles are influenced by land use changes. We sampled the insects using aerial fruit-baited traps weekly from September to December 2012, in five sites of Brazilian Atlantic Forest, Eucalyptus plantations and pasturelands (Urochloa spp.). We find that compositional changes of beetle assemblages are completely represented by nestedness patterns, either among or within habitats. When accounting for abundance, except for Eucalyptus sites, there are a similar contribution of change and loss of individuals among and within habitats. Within Eucalyptus sites, assemblages are completely nested in terms of species and individuals. Eucalyptus sites are a poor-homogenized subset of some disturbance-tolerant flower chafer beetle species also found in forest and open habitats (such as pastures). When resources are available, these beetles can inhabit both forest and open habitats and appear to be ‘guests’ in Eucalyptus sites, using them only when moving through space. Finally, conversion of Atlantic Forest sites into Eucalyptus causes poor-homogenized assemblages of flower chafer beetles.