Determining the Effects of Nitrogen Pollution on Lichens in the Wind River Range Mountains

An important concern of land managers is how anthropogenic sources of atmospheric nitrogen deposition influence the health of forested ecosystems in the western US. Industrial and agricultural sources of reactive nitrogen in the atmosphere have the potential to alter functioning of forested ecosystems far from pollutant sources. This study evaluates the effectiveness of lichens as a natural indicator of the source and amount of atmospheric nitrogen deposition in forested ecosystems in the Wind River Range of Wyoming. Analysis of δ15N and δ13C of lichen biomass will evaluate how lichens record the source and biological effect of nitrogen deposition. The data collected from two lichen species, Letharia vulpina and Usnea lapponica, will be developed with GIS modeling to interpret the spatial pattern of nitrogen deposition in relation to a large region of natural gas drilling, which is a potential source of reactive nitrogen in the atmosphere on the western slope of the Wind River Range.