Under the direction of Dr. Donald Grayson, MS Elizabeth Scharf will collect data for her doctoral dissertation. MS Scharf wishes to determine the effect that prehistoric Native Americans had on their environment. This is a very strongly debated topic and the answer is important because it helps to determine the natural environmental baseline against which human actions should be measured. Many scientists have argued that the level of prehistoric technology was so low, that prior to European colonization, vegetation was maintained in an essentially pristine condition and that the changes which are clearly indicated in the environmental record were due to climate change or other non-human causes. Others however have maintained that even without metal implements and large scale forest clearance, actions by prehistoric Native Americans had a significant effect, primarily through accidental and purposeful burning. When present in significant numbers, humans cause fires and these occur more frequently than those resulting from other actions such as lightning strikes. The ecological effects of more frequent burning are very different from situations where such episodes are more widely spaced in time. To examine this question MS Scharf will collect cores from a series of lake basins in Washington State. She has chosen a region where extensive archaeological research has been conducted and changes in prehistoric population densities can be calculated over time. Through the study of volcanic tephra and radiocarbon determinations, segments of the cores can be accurately dated. Analysis of oxygen isotope ratios will provide information on climate change. Pollen and charcoal respectively will provide the bases for reconstructing vegetation and fire history. Counts of the spore Sporomiella serve to monitor herbivore density since these relate to the amount of dung being washed into each basin. Through statistical analysis of these complementary data bases, the effect of human agency on vegetation can be addressed. This research is important for several reasons. It will provide information on long term human-environment interaction, an issue of interest to geographers, paleoecologists and archaeologists. It will also assist in training a promising young scientist.
