GIS Aids Prairie Restoration in Mississippi
THE USE OF THE HISTORICAL RECORD AND GRAPHICAL INFORMATION SYSTEMS TO GENERATE A SUITABILITY MAP FOR PRAIRIE RESTORATION IN MISSISSIPPI
Michael Tobit Gray, Timothy Schauwecker , Kate Grala.
Presented at the 36th Natural Areas Conference, “Living on the Edge: Why Natural Areas Matter”, Vancouver, Washington, USA, September 15-18, 2009.
An exhaustive search of General Land Office records was conducted with a goal of identifying the historic locations of prairies in the Jackson Prairie Belt region of Mississippi. These records include surveys of township and section lines made by government surveyors following tribal land cessions in the early 19th century. Over 300 locations of entry and exit points of Jackson Belt prairie patches were found and transcribed. The points were converted to x and y coordinates in ArcMap, and a tool was created which automated this process, which resulted in the generation of a series of vector lines representing areas in which the surveyor was crossing prairie. This map was compared to one created and published by John Barone by digitizing plat maps from the same era. Patches not included in the plat maps are evident. While Barone‘s shapefiles contain more information about the patch sizes and margins, the lines generated from the transcriptions of survey notes result in more precisely georeferenced locations. Additional datasets, including National Forest Boundaries, distance to primary roads, transmission lines, current land use and 16th section land, were added to the GIS and analyzed as variables affecting suitability for restoration. These variables were weighted according to input from stakeholders, including the Nature Conservancy of Mississippi and their partner groups. The weighted raster files were inserted into a map algebra equation in ArcMap resulting in a suitability map. Locations deemed most suitable were confirmed as such through aerial photography and site visits.