This project will continue long-term measurements and experiments at the Fernow Experimental Forest in order to better understand how air pollution affects the fertility, productivity, and composition of hardwood forests in central Appalachia. Recent changes at this site suggest that continued acid deposition will deplete essential soil nutrients and alter the balance of available nutrients in ways that reduce forest productivity. Continuing measurements of precipitation, stream water, soils, and vegetation (in both untreated and experimentally manipulated sites) will answer several important questions: (1) Is there evidence that acid deposition has reduced forest productivity ?; (2) How long can some forests resist the effects of chronic acid deposition ?; (3) Why are long-term changes in stream-water chemistry at this site different than changes observed in other polluted regions of the eastern US ?; and (4) Will continued acid deposition alter the diversity and composition of tree species?
Long-term data are rare but necessary for detecting environmental change, and for quantifying its ecological impact. Thus, results from this project will significantly improve our understanding of the link between changes in air pollution and forest productivity in ways that can inform public policy, ecological theory, and forest management practices.