Developing an approach for using the soil phytolith record to infer vegetation and disturbance regime changes over the past 200 years

Historical ecology is a field of research that seeks to explain how ecosystem change is manifest upon the landscape over time. This interdisciplinary synthesis of information draws from the human and the biological archive. Historical ecology helps characterize reference conditions and the historic range of variability in ecosystem structure that is useful in understanding ecosystem dynamics and function, provides input to resource managers, and guides restoration efforts. The methods in historical ecology cover a wide range of temporal and spatial scales. However, the evidence for time scales of less than 200 years is largely limited to the human archive and dendrochronology. Additional approaches for this more recent time period could provide important information for understanding the vegetation changes in the past 200 years especially where dendrochronology is not applicable. This research seeks to expand the biological evidence for inferring vegetation and disturbance regime changes in the Western United States since settlement in the 1800s by developing an approach that combines the human archive and soil phytolith analysis. We examined the human archive for vegetation and disturbance regimes change in the City of Rocks National Reserve, Idaho, US. In addition, we examined the phytoliths of native and introduced species in the area and looked at how well the soil phytolith record reflects recent wildfires. Our results indicate that this combination of history and soil phytolith analysis will be a useful approach for inferring vegetation and disturbance change in ecological histories.