PARENT SESSION
Symposium 11: How Will the Southeast's Biological Diversity Respond to Climate Change?
Organized by: P White, J Walker, and J Sutter
Wednesday, August 6. 8:00 AM to 11:30 AM, SITCC Chatham Ballroom B.
Endemism, hot spots of diversity, and ecosystems in the Southeast: the template on which climate change will act.
White, Peter*,1, McKnight, Meghan1, Walker, Joan2, 1 University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA2 US Forest Service, Clemson University, Clemson, South Carolina, USA
ABSTRACT- The Southeast has many narrow endemics, rapid geographic turnover, and continental high points of diversity in a number of groups, including fish, amphibians, turtles, freshwater mollusks, land snails, cave organisms, and some groups of insects and plants. Rather than occurring in the same places and ecosystems, however, the endemics and hot spots of diversity are widely scattered across the region. The distribution of ecosystems is also complex, with gradients of water and nutrient availability creating locally changing compositions and structures. We compare the pattern of richness, endemism, and globally rare species for different taxonomic groups in order to better understand the vulnerabilty of this rich biological area to climate change. For vascular plants, we show that the number of narrow endemics decreases much more quickly northward than the decrease in total richness, that endemism increases from west to east across the Southeast, and that the average similarity is lower and the decay of similarity with distance is higher across the Southeast than across the glaciated North. Glaciation has evidentally left a long-lasting imprint on patterns of biological diversity in eastern North America. These data suggest that conservation by ecosystem type is disjunct from conservation of species diversity. Patterns in the the Southeast's high levels of endemism suggest a unique and high degree of vulnerability to climate change.
Key words: biodiversity, endemism, biogeography, distance decay