Multidisciplinary approaches to the study of forest dynamics in south central Indiana and southern Illinois
Extensive deforestation and subsequent reforestation has had a profound effect on the social and ecological systems in south central Indiana and southern Illinois. Trees have invaded former agricultural areas creating a diverse forested environment of secondary growth that has gained significant public ownership in the past century. This dissertation considers ecological and social dimensions of these changes through study of forest biodiversity and the diversity of opinion concerning forest management. It examines spatial patterns of tree growth in old fields, the performance of computer-based forest composition models, and human dimensions of national forest management. Seed dispersal mode is an important factor that explains the initial spatial patterns of seedling and sapling densities in old fields. Less is known about the lasting impacts limits of seed dispersal have on subsequent stages of forest succession. This study examines spatial patterns of seedling and sapling density in old field forests (aged 25 years) to determine what impacts seed dispersal limitation have on forest composition. Seed dispersal mode (bird, wind, or mammal) is one of the significant factors that explain patterns of tree seedling and sapling densities in these settings. Another aspect of this dissertation considers how landscape-scale moisture differences affect forest cover type using a GIS-based approach. The integrated moisture index (IMI) uses slope and aspect algorithms in a GIS to model differences in soil moisture in order to explain forest composition. There is a stronger correlation between forest composition and the IMI in a heavily-dissected landscape than in rolling terrain. While the IMI is an important factor affecting forest communities, disturbance from land-use history may reduce the importance of moisture gradient as a determinant of forest composition. Additionally I describe the social landscape of southern Illinois in a social assessment of Shawnee National Forest. The objectives of this social assessment were to determine social and economic characteristics of the region, describe the nature of the community—forest relationship, and identify socioeconomic trends. It describes user opinions of the forest and the socioeconomic characteristics of the surrounding communities in order to elucidate the relationship between the Shawnee National Forest and its stakeholders.
0768: Environmental science