Response of dung beetle diversity to human-induced changes in a tropical landscape

This paper examines dung beetle communities in remnant patches of tropical deciduous forest at Veracruz, Mexico, as a case study of the effects of tropical deforestation on biodiversity. The two study areas have a common biogeographic history and similar macroclimatic conditions and have been modified by human activities to different extents. The main difference between them is that cattle, which provide the dung beetle's food supply, are present in only one of the areas. Comparison of the dung beetle faunas sheds light on the relative importance of forest cover versus food supply as the principal factor determining the structure and diversity of the fauna. This comparison, which we broaden through an examination of data from other localities in central Veracruz, permits us to speculate about what happens to biodiversity when a tropical deciduous forest undergoes modification of varying type and intensity. Where tree cover has been most modified, native forest species undergo local extinction and are replaced by open area species. On the whole, there has not been a net reduction in species richness (gamma diversity) in the fragmented landscape of central Veracruz, although local species richness (alpha diversity) has diminished.