48 YEARS OF LANDSCAPE CHANGE ON 2 CONTIGUOUS OHIO LANDSCAPES

This study analyzes the current and historic structure of two contiguo us, rural landscapes covering approximately 242 km2 in central Ohio, U SA: a till plain landscape with relatively homogeneous topography and soils, and a moraine landscape with greater geomorphological diversity and heterogeneity. These landscapes were chosen because they were bot h heavily dominated by agriculture during 1900-1940 and were both init ially surveyed by the metes-and-bounds system. They differed, however, in the temporal pattern of settlement and development and in the inhe rent agricultural capability of their soils. We combined analysis of a erial photographs from 1940, 1957, 1971, and 1988 with historical arch ives and other available mapped data in a GIS data base to facilitate analysis of both spatial and temporal patterns of change. On the morai ne, the agricultural matrix decreased over time as forest, urban/subur ban areas, and industry increased. In contrast, on the till plain agri cultural landcover increased through 1988, with concommitant decreases in upland forest and oak savanna. The moraine landscape exhibited gre ater diversity and equitability than the till plain on each date. The till plain had its greatest diversity and equitability in 1940, wherea s the moraine increased in diversity and equitability during each time period. The undulating topography of the moraine encouraged landcover dynamism rather than stability, whereas the more homogeneous till pla in exhibited considerable inertia. Patch and matrix shape remained con stant and predominantly angular over the 48 year study period. Differe nces in the physical environment, especially topography and soil capab ility, and the socioeconomic environment, especially agricultural poli cies and patterns of urbanization, resulted in these two contiguous la ndscapes having different trajectories of change. It is clear from thi s study that socioeconomic factors must be combined with the physical settings to fully understand patterns of change in human-dominated lan dscapes.