Villages, vegetation, bedrock, and chimpanzees: Human and non-human sources of ecosystem structure in southwestern Mali.

摘要

This dissertation shows that both human activities and biophysical processes interact in complex ways to create an emergent ecosystem structure in southwestern Mali. This dissertation includes five body chapters. The first chapter is an analysis of settlement history in the research area, and situates the research in the context of current conservation practice in Mali's Bafing Biosphere Reserve. This chapter shows that the indigenous Maninka people practice shifting settlement, and that frontier-style settlement expansion is not occurring in the area, as conservationists have assumed. The second chapter is an ethnographic study of Maninka physical geography terms, and shows that Maninka farmers perceive the landscape as highly heterogeneous, with few areas suitable for settlement or cultivation. The third chapter examines floristic patterns across the landscape, and shows that most floristic variation is due to edaphic features, especially the hydrogeology of a specific type of sandstone bedrock. Human activities have variable affects on vegetation, depending on various socioeconomic and biophysical factors. The fourth chapter shows that humans have affected the distribution of the baobab tree across the research area through activities that create suitable baobab habitat in settlement sites. The final body chapter shows that anthropogenic baobab groves represent important habitat for chimpanzees, and that conservation policies that affect settlement practice may reduce baobab regeneration and thus reduce chimpanzee habitat in the long term.