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2017 Monitoring and tracking wet nitrogen deposition at Rocky Mountain National Park

October 31, 2019

The Colorado Department of Public Health and Environment (CDPHE), the National Park Service (NPS), and the U.S. Environmental Protection Agency (EPA) issued the Nitrogen Deposition Reduction Plan (NDRP) in 2007 to address the effects and trends of nitrogen deposition at Rocky Mountain National Park (RMNP). The agencies chose a glidepath approach to reduce wet nitrogen deposition to a level of 1.5 kilograms of nitrogen per hectare per year (kg N/ha/yr) by the year 2032 to protect sensitive ecosystems within RMNP from adverse effects. Another goal of the NDRP is to “reverse the trend of increasing nitrogen deposition at the park.” Trends in wet deposition data were analyzed at three sites in RMNP and three regional sites outside of the park. Wet nitrogen deposition (5-year rolling average) at Loch Vale in RMNP was 3.3 kg N/ha/yr, which is above the glidepath (2.4 kg N/ha/yr) in 2017. Wet nitrogen deposition has not decreased at RMNP or other sites in the region over the long-term. Ammonium concentrations showed a statistically significant increasing trend at all sites and nitrate concentrations showed a significant decreasing trend at four of the five sites over
the period of record. In more recent years (2011-2017), wet nitrogen deposition showed no
significant trend at monitoring sites in RMNP. Ammonium concentrations also showed no significant trend over the short-term, however nitrate concentrations did significantly decrease at two of the six sites.

Publication Year 2019
Title 2017 Monitoring and tracking wet nitrogen deposition at Rocky Mountain National Park
Authors Kristi Morris, M. Alisa Mast, Gregory A. Wetherbee, Jill S. Baron, Jim Cheatham, Jim Bromberg, Lisa Devore, James Hou, Kristi Gebhart, Mike Bell, David Gay, Michael Olson, Timothy Weinmann, Daniel Bowker
Publication Type Report
Publication Subtype Other Government Series
Series Title Natural Resource Report
Series Number 2019/1905
Index ID 70203201
Record Source USGS Publications Warehouse
USGS Organization Colorado Water Science Center