Dry Nitrogen Deposition in the Grand Tetons: a Baseline Study
Plant ecosystems are largely dependent upon nitrogen, but recent decades have presented many ecosystems with unhealthy increases in nitrogen deposition. Though a majority of nitrogen is thought to be deposited via precipitation (wet deposition), it has been discovered that as much as 25% of total nitrogen deposition can be attributed to gases and particulate-matter (dry deposition). The extreme sensitivity of terrestrial, alpine ecosystems has produced a substantial interest in the effects of nitrogen deposition in Grand Teton National Park (GTNP). Currently, GTNP is one of the most at-risk parks in the country when considering the effects of increased nitrogen content (nutrient enrichment). As dry deposition has not been previously measured in GTNP, the current study conducted baseline measurements of nitrogenous dry deposition at two locations within the park. Ammonia contributed the most nitrogen, followed by ammonium, nitric acid, and nitrate, respectively. Total nitrogen dry deposition was estimated at 2.41kgN/ha/yr for the lower elevation site (Driggs) and 2.12kgN/ha/yr for the higher elevation site (Targhee).