Towards a Swahili Historical Ecology: Phytolith-based Analysis in Coastal Eastern Africa since AD 600

This dissertation reconstructs the diachronic implications of ongoing interaction between Swahili peoples and coastal environments in three regions of Tanzania, Eastern Africa since AD 600. Previous archaeological investigations document the presence of Iron Age populations across the coast by this point. Iron Age people of Eastern Africa occupied villages and practiced mixed subsistence economy that featured African grains and animal husbandry. Through time, some villages became entrepôts from which residents managed commercial ties that extended into continental Africa and across the Indian Ocean. I rely on phytolith, soil, and archaeological samples recovered from archaeological contexts to evaluate the change in botanical communities through time that occurred in conjunction with the ongoing application of mixed subsistence economies, urbanization, and other social choices apparent across the regions. The paleoethnobotanical perspectives from this research contribute to a growing literature that frames environmental conditions as contributing to the formation of modern conditions.

I interpret the interaction between coastal peoples and local ecologies through the theoretical framework of historical ecology. This paradigm holds that contemporary environmental conditions reflect the ongoing interaction between cultural, biological, and physical factors. Each constituent is thought to have the capacity to bring about change to the overall system; thus, historical ecology is an interdisciplinary paradigm that requires data from all three (cultural, biological, physical) constituents.

The regions under consideration include Songo Mnara Island, Mikindani Bay, and northern Pemba Island. Archaeologists had previously defined social chronologies, geographic extent, and material expectations from these three sites. The unique social histories and environmental situations apparent in the three regions lead me to expect variability in the interaction between residents and local ecologies. The phytolith-based results from this research demonstrate a homogeneous approach was expressed towards settlement in plant communities and subsequent approaches to plant resource management. This suggests that a general set of socioenviornmental strategies may accompany the social traits shared between coastal peoples since AD 600.