This project used GIS in selecting a landscape management approach for the Platt District of Chickasaw National Recreation Area in Oklahoma. The Platt District is a 900-acre historic landscape designed by the National Park Service in 1940 (Fig 1). Over time the ecology of this landscape has changed significantly, with the area’s original prairies replaced with woodland communities. This transformation was caused by red cedar expansion, fire suppression and “hands-off” park management. As a result, both the historic integrity and ecological health of this cultural landscape are threatened.GIS analyses were done to facilitate vegetation management decisions and specifically to select areas for prairie rehabilitation.
Most analyses used ArcGIS (ArcMap, ArcToolbox and ArcCatalog), though early analyses also used ArcView 3.3. Modeling was performed both in vector and raster format. Several extensions were used, including Spatial Analyst, 3D Analyst and Image Analyst.
Analysis criteria were based on historic research, cultural landscape preservation methodology, and ecological best management practices. Research indicated that woodland communities should be retained along major ravines, along boundaries, in areas of high soil erosion hazard, and in places where woodlands occurred historically. Research also indicated that areas where prairie existed historically should be cleared of woody invasives and returned to prairie. Analyses therefore identified prairies that changed the least since 1940 and then determined which of these were most suitable for grassland rehabilitation. Four different suitability models reflecting various management approaches were considered: an historical preservation model, an ecological preservation model, an educational model and a balanced model. The balanced model—a combination of the other three models—was used for the final selection of areas to be rehabilitated (Fig. 2).
GIS allowed the explicit weighting of the cultural, ecological and management factors used to make the decision, clarifying goals for the client and public. Furthermore, by using GIS, the area selected as target vegetation can be easily modified, if required, to reflect changes in park management goals as they occur.