Master of Science (MS), Wright State University, 2002, Biological Sciences

Zimmerman, Christopher Lee. M.S., Department of Biological Sciences, Wright State University, 2002. Using Ecological Land Units in a Gap Analysis for Conservation Planning in a Southwestern Ohio Watershed. Gap analysis is a method to identify insufficiency in biodiversity protection. In degraded agricultural landscapes, it requires information on the past, present, and the potential natural distribution of forest vegetation to construct a comprehensive nature reserve network. Using Geographic Information Systems (GIS), I conducted a biodiversity gap analysis to assess the representation of ecological land units (ELUs) supporting forest vegetation both within and external to the current reserve network in the Lower Twin Creek Watershed (LTCW), southwestern Ohio. I used this analysis to make conservation planning recommendations to the local park district. ELUs are based on relatively stable associations of soils, physiography, and potential natural vegetation. In heavily deforested landscapes, such as the LTCW, ELUs model a more intact functioning landscape by predicting the distribution of potential natural forest vegetation. ELUs were classified using multivariate and cluster analyses on forest canopy tree species and seven physiographic and soil variables derived from digital elevation models and a soil series map in GIS. A cluster analysis of the five most significant variables (landform, drainage, hillshade, curvature, and percent slope) influencing vegetation distribution resulted in nine discrete ELUs. They included uplands dominated by Fagus grandifolia – Acer saccharum, dry slopes dominated by Quercus spp. - Carya ovata, mesic slopes dominated by a mixed mesophytic community, and wet floodplains dominated by Platanus occidentalis – Populus deltoides. A reference ecosystem map was constructed using ArcView GIS Spatial Analyst with the five environmental variables identified in the multivariate analysis. To determine the area of forest cover in each ELU within (open full item for complete abstract)

Committee: James Runkle (Advisor) Subjects: Biology, Ecology