Applying Biodiversity Gap Analysis in a Regional Nature Reserve Design for the Edge of Appalachia, Ohio (U.S.A.)

Abstract

A biodiversity gap analysis is a method, now usually employing geographic information systems, for identifying deficiencies in existing biodiversity protection. Key principles of gap analysis were applied to a region of southcentral Ohio (U.S.A.) known as The Edge of Appalachia as part of a detailed, large‐scale (1:24,000) nature reserve design project. By combining Landsat thematic mapper imagery with ancillary data (bedrock geology, elevation, slope, aspect, and stream proximity), a rule‐based model was developed to differentiate and map the natural plant communities present in the 378‐km2 study area. The model was then used to generate a map depicting the most likely presettlement plant community distributions for the area. These two maps were compared against the 5273 ha owned and managed by state and local conservation organizations. For the current natural plant community distributions, regional land‐protection efforts represented each plant community proportionally; however, comparison with the presettlement vegetation clearly identified serious historical losses of several plant community types. Our results suggest that future land acquisitions should emphasize those plant community types that were once more widespread in the region prior to European settlement, a time when natural processes were less compromised by human activity. Current and historical plant‐community mapping results were combined and evaluated using the ownership parcel as the fundamental mapping unit. From parcel‐based desirability maps a conservation plan was developed that addressed community deficiencies using a representation target of25% for each community type, as derived from the modeled presettlement landscape.