Nitrogen Deposition Effects at Mount Rainier
Science Students: Justin Poinsatte, School of Biological Sciences, and Jason Williams, Civil & Environmental Engineering (Pullman)
Student Reporters: Max Reister, Tesia Lingenfelter, and Renee Hausske, Murrow College of Communication (Pullman)
Two Washington State University PhD students are helping the National Park Service determine if nitrogen pollution is negatively affecting national parks in Washington state. Jason Williams (Civil & Environmental Engineering) and Justin Poinsatte (School of Biological Sciences) have been conducting research in the high elevation regions of Mount Rainier National Park to identify the impacts of atmospheric nitrogen pollution on alpine lakes and meadows, respectively.
Nitrogen released by cars, power plants, ranching, and agriculture outside national park boundaries can be transported through the atmosphere and end up even in remote high elevation landscapes like Mount Rainier. When it falls onto high elevation ecosystems through rain or dry deposition (nitrogen gases or nitrogen attached to dry particles), nitrogen can act as a fertilizer that causes lake algae blooms and is detrimental to wildflower meadows that attract visitors to the park.
These changes are more than just an aesthetic problem for visitors. By fertilizing aquatic and terrestrial ecosystems, nitrogen deposition can reduce biodiversity, increase greenhouse gas emissions, and affect ecosystem services, the ecological resources and processes humans rely on. The National Park Service is also mandated by law to protect parks from air pollution, including nitrogen pollution. The Clean Air Act directs the National Park Service and other land management agencies to prevent air quality deterioration in national parks and wilderness areas. The National Park Service Organic Act, which created the National Park Service, and the Wilderness Act provide additional similar mandates.
To address these mandates, the National Park Service, National Forest Service, and other federal agencies have conducted and supported research to estimate ‘critical load’ nitrogen deposition rates: the amount of N deposition at which specific ecological impacts begin to occur. Although the National Park Service and National Forest Service have no authority to regulate nitrogen emitted outside park and forest boundaries, they can communicate the impacts of nitrogen pollution and critical load deposition rates to entities with regulatory authority, such as states and the U.S. Environmental Protection Agency. In Rocky Mountain National Park, nitrogen deposition research stimulated an agreement between state and federal agencies, and farmers and ranchers to reduce the amount of nitrogen entering the park through the atmosphere.
Preliminary results from Williams’ research indicate park lakes appear relatively unimpacted by nitrogen deposition compared to lakes in the Rocky Mountains, but are also sensitive to future N deposition increases. If nitrogen deposition increases lake nitrogen concentrations, the amount of algae in lakes will increase and the types of algae in lakes will change. Preliminary results from Poinsatte’s research indicate nitrogen deposited onto alpine meadows doesn’t stay there; it can exit meadows as nitrous oxide (a greenhouse gas) or leach into aquatic systems and potentially increase lake and stream nitrogen concentrations and affect algae. The National Park Service will use research conducted by Williams, Poinsatte, and others to help determine if current deposition rates have negative impacts on park ecosystems, and thus to help decide if emissions reductions should be recommended to air-quality policy makers.