In the Southeastern U.S., “insular ecosystems” may be particularly vulnerable to ecological effects from climate change. These insular ecosystems share a few key biogeographic characteristics: (1) occurrences that are spatially discrete, (2) relatively small geographic footprints, and (3) with steep ecological and environmental gradients at their boundaries. Examples include rock outcrop ecosystems (e.g. Piedmont granite outcrops, Appalachian high-elevation outcrops), grasslands (high-elevation balds, xeric limestone prairies), isolated wetlands (Carolina bays, karst depression wetlands) and riparian riverscour systems. Such insular ecosystems tend to support concentrations of endemic and disjunct species; thus their contributions to regional biodiversity are often disproportionate to their small geographic sizes.
For this project, researchers conducted a systematic literature review to document the biodiversity of selected insular ecosystems and to evaluate their potential vulnerability to climate change. They developed a conceptual model for ecosystem integrity based on abiotic stress regimes which fluctuate within certain upper and lower bounds and applied this model to generate hypotheses for ecological alteration based on changes in temperature or precipitation. They also conducted a 2-year field investigation in Limestone Cedar Glades—a threatened, insular ecosystem of the Interior Low Plateau—to explore links between hydrology, soil physical and chemical properties, and ecological outcomes such as soil microbial community structure. This case study serves as an example of the type of empirical research that researchers argue is necessary to better evaluate the climate-change vulnerability of this class of ecosystems.
