GLOBAL WARMING AND THE SPECIES RICHNESS OF BATS IN TEXAS

General circulation models provide predictions for global climate unde r scenarios of increased atmospheric CO2. Climate change is expected t o lead directly to changes in distributions of vegetation associations . Distribution of animals will also change to the extent that animals rely on vegetation for food or shelter. Bat species in Texas appear to be restricted, in part, by the availability of roosts. We used geogra phic information systems and the Holdridge vegetation-climate associat ion scheme to model the effect of climate change on bat distributions and species richness in Texas. Habitat characteristics for each specie s were identified from the literature and included vegetation, topogra phy, and availability of caves. We assumed caves and topography to be fixed relative to climate. Vegetation changes were predicted from the Holdridge vegetation-climate association scheme. The redistribution of bats following climate change was predicted based on the new location s of suitable habitat characteristics. Under conditions of global warm ing tropical forests were predicted to expand into Texas; tree-roostin g bats were sensitive to this change in vegetation. Cavity-roosting ba ts were less affected by changes in vegetation, but, where response wa s predicted, ranges decline.