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Nitrogen Risk Assessment

Photo of arid shrubland ecosystem, Joshua Tree NP, California. Photo of subalpine meadow ecosystem in North Cascades NP, Washington. Photo of a high elevation lake in Glacier NP, Montana. Photo of wetland ecosystem in Everglades NP, Florida.
Some ecosystems, such as arid shrublands, subalpine meadows, remote high elevation lakes, and wetlands, are sensitive to the effects of nutrient enrichment from atmospheric nitrogen deposition.

This report series evaluates the relative sensitivity of NPS parks and inventory & monitoring networks to potential nutrient enrichment effects caused by atmospheric nitrogen deposition. Such effects can be caused by the addition of oxidized nitrogen (NOx) and/or reduced nitrogen (NHx) to natural ecosystems. Nutrient nitrogen enrichment can occur in both terrestrial and aquatic ecosystems. Nitrogen from air pollution sources can alter plant and algal communities and affect biodiversity.

The reports provide a relative risk assessment of nutrient enrichment impacts from atmospheric nitrogen deposition for 270 parks in 32 inventory & monitoring networks. This assessment considers three factors that influence nutrient enrichment risk to park resources from atmospheric nitrogen deposition:

  1. Nitrogen Pollutant Exposure
  2. Ecosystem Sensitivity
  3. Park Protection mandates
National parks and networks are ranked according to each of these factors (themes). An overall risk ranking is then calculated based on averages of the three theme rankings.

Main Report

The main report provides background for the project, describes the assessment methods, and summarizes ranking results. It should be used in conjunction with each network report.

Inventory & Monitoring Network Reports

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Last Updated: January 08, 2014