Year Established: 2015 Start Date: 2015-05-01 End Date: 2015-08-01
Total Federal Funds: $1,000 Total Non-Federal Funds: $440
Principal Investigators: Sarah Benjaram, Sarah Benjaram
Abstract: My research seeks to investigate the physical and chemical weathering processes that produce soil from rock and move it downslope, delivering it to the river system. This is especially important in the Bitterroot River watershed where high sediment loads are an ongoing issue that the Department of Environmental Quality, the Environmental Protection Agency, and local groups have all sought to address in recent years. The chemical and physical processes that transform rock into soil, mix it, and move it downslope to the river channel are a function of climate, past and present. Quantifying these controls on soil formation and weathering is essential to our understanding of how landscapes developed to their present state and how they may evolve with climate change. The influence of present climate on soil development is widely studied: chemical weathering is sensitive to both temperature and moisture, as are the fire regimes and related events that deliver sediment to channels. However, past climates also control the morphology of modern landscapes, and in fact may be more important than present climate, at least in some instances. Glaciers that occupied the Bitterroot Valley in the Pleistocene deposited debris and carved valleys, leaving a topographic legacy that helps determine the transport patterns of modern soil. I will compare soil formation and weathering rates in glaciated and unglaciated landscapes in order to compare the relative effects of past and present climate on modern landscape evolution.