Assessing the Effects of Nitrogen Deposition on High-Elevation Plant and Soil Communities
Project ID: P12AC10794
Federal Agency: National Park Service
Partner Institution: University of Washington
Fiscal Year: 2012
Initial Funding: $82,800
Total Funding: $154,800
Project Type: Research
Project Disciplines: Biological
National Park: Pacific West Region Washington
Principal Investigator: Zabowski, Darlene
Agreement Technical Representative: Rochefort, Regina
Abstract: Increasing levels of nitrogen (N) deposition have been identified as critical concerns for ecosystems worldwide. High-elevation plant communities are generally adapted to low soil resource supply and increases in N may result in significant changes in biomass and species composition. Understanding the effects of N deposition on alpine plant and soil communities is needed for the development of “critical loads” to inform and improve air quality policy and protect high-elevation ecosystems. The term “critical loads” is used to describe the point at which the natural system is damaged by air pollution. This project will use fertilization of alpine plant communities to document effects on plant and soil community dynamics and to derive initial estimates of critical loads of N for alpine systems in North Cascades, Mount Rainier, and Olympic National Parks and will provide insight for park management policies. The overall objective is to evaluate the effects of atmospheric N deposition on the structure and function of alpine ecosystems in these parks. Specific tasks are: (1) to initiate an in situ N addition experiment to determine alpine vegetation and soil process response to N enrichment; (2) identify critical loads of N for dominant high-elevation plant species; (3) provide data on Pacific Northwest high-elevation plants and mycorrhizas for the adaptation of the ForSAFE-VEG model to US alpine plant ecosystems; and (4) collect all data in a manner that will allow them to be compared with similar experiments in other national parks. National Park Service staff will be involved in several ways, including working with the cooperator to identify and select sample sites, establish vegetation plots, and collect data. Public benefits of this project including improved protection of public lands, protection of Class I Airsheds within Pacific Northwest national parks and Wilderness Areas, and improved understanding of potential changes to park ecosystems. The experimental application of nitrogen to alpine ecosystems will enhance our understanding of the rate and magnitude of changes that may occur in high-elevation ecosystems without improved air quality standards. This research will allow scientists and managers to estimate the amount of pollution exposure (i.e., nitrogen) below which significant effects are not expected to occur. This level of nitrogen (the critical load) is a valuable tool both in the scientific and regulatory arenas for protection of ecosystem process.