Abstract
In fragmented tallgrass prairie remnants within eastern Kansas, smaller patch area, greater isolation, and poorer matrix quality are predicted to result in (1) decreased species richness, (2) decreased site `quality,' and (3) decreased presence of specialist species. Within five counties, 301 native tallgrass remnants were surveyed. Total site area, as well as habitat heterogeneity, contributed to richness and quality, but isolation and matrix quality did not. In fact, isolation and matrix quality appeared to contribute to decreasing richness and quality. These results can be explained by regional environmental variation and historic non-random process of human landscape changes at the time of settlement. This suggests that the hypothesis that dispersal plays a role in the community assembly of tallgrass prairie remnants is probably false. Although species-rich communities may persist for decades and possibly centuries after fragmentation, in the long term the effects of random local extinction have been underestimated for native tallgrass prairie communities.