Coefficient of Conservatism Rankings for the Flora of Georgia: Wetland Indicator Species

Wetland habitats currently cover about one-fifth of Georgia and have been reduced in acreage by as much as twenty-five percent over the past two centuries due to anthropogenic activities. Accurate identification and careful study of these areas are crucial for their preservation and for compliance with federal and stat e environmental regulations. Several vegetation-based biological assessment methodologies have been developed to define wetlands and to assess their quality. One major wetland delineation system, mandated by federal law, incorporates the National Wetland Plant List (NWPL), a classification system ranking plant species in five indicator categories according to fidelity and preference for wetlands or uplands. These rankings were recently updated via a comprehensive and collaborative nationwide effort involving four government agencies and teams of wetland specialists. Another expert-based indicator system, coefficients of conservatism, is the foundation of the floristic quality index, a metric widely used in the United States for assessing ecological condition of wetlands (as well as other plant communities). The coefficients are based on breadth of habitat preference(s) and tolerance to disturbance, with exotic and ruderal species receiving the lowest scores and ecologically conservative species assigned the highest scores. A team of four botanists, proficient with the flora of Georgia, convened to assign coefficient of conservatism rankings to the 2262 NWPL species for the state. The resulting web-accessible database, which includes information such as regional wetland rankings and conservation status, is described here.