Temporal Assessment of Urban Forest Patch Dynamics Using Medium Scale Aerial Photography and GIS

Abstract

The purpose of this study was to evaluate the spatial and temporal change of the urban forest in three relatively new subdivisions in the city of Stillwater, Oklahoma, in an attempt to determine appropriate tree canopy coverage post-urbanization. Geographical Information Systems (GIS) software was used to evaluate changes in the urban forest by digitizing, manipulating and analyzing the tree canopy polygons created from six decades of vertical aerial photographs. All three study sites showed trends of significant canopy increase from the beginning of the study timeline, i.e., 1938 or 1949, through the early 1990's, which was an unexpected outcome. Modest gains in canopy cover were evident between 1940 and 1970 but significant gains seemed to occur between 1970 and 1995. In the last seven years of the study, two sections showed a significant increase in urbanization with a concomitant decrease in tree canopy cover. However, one study site, Hidden Oaks, had no apparent loss of tree canopy in relation to an increase in population density.