Doctoral Dissertation Research: Diet and Population Mobility

This doctoral dissertation project examines the impact of changes in population pressure and dietary diversification on the long-term sustainability of small-scale, self-sufficient societies. The underlying rationale for this project, grounded in empirical research in ethnobotany and ecology, suggests the implementation of multiple dietary plant staples allows food producing societies to increase and stabilize food yields. Diverse food systems can thus constitute a strategic response to episodes of demographic growth. Archaeology can further substantiate these insights because it provides subsistence and population data on the centennial and millennial scales, highlighting successful strategies that have stood the test of time. At present, the link between subsistence diversity and socio-environmental sustainability increasingly draws interdisciplinary attention, largely due to the vulnerabilities of industrial farming. Contemporary farming is predicated on the continued success of high-yielding monocultures, but the biological simplification of food systems has increased dependency on human inputs and susceptibility to change. Understanding the long-term implications of species variability in farming systems is therefore of value in the United States today. The project addresses these issues by looking at two research questions in the context of an archaeological habitation site where both farming and plant foraging took place. The project first determines the extent of demographic change at the site throughout its occupation: this is accomplished through an analysis of wood charcoal remains that have already been excavated. Based on ethnographic observations of fuelwood collection, charcoal remains are expected to reflect population levels because small groups that do not experience resource stress tend to only select a handful of tree species from easy-to-access locations. The investigator therefore measures changes over time in the number of tree species used for fuel, as well as the accessibility of where the fuel was collected. The latter is assessed through oxygen stable isotope analysis, which represents a methodological innovation in archaeobotany. Data concerning the type of fuelwood that was selected over time serves as a proxy for population pressure. A second question focuses on whether the local food system became more diverse to cope with increased population pressure. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.