Acidification Risk Assessment

Winter stream in Great Smokey Mountains National Park
Some ecosystems and vegetation types, including
high-elevation lakes, headwater streams, sugar maple and red spruce trees, are sensitive to the effects of acidification from atmospheric nitrogen and sulfur deposition.

NPS Photo

This report series evaluates the relative sensitivity of National Park Service (NPS) parks and inventory & monitoring networks to potential acidification effects caused by atmospheric nitrogen (nitrate and ammonium) and sulfur (sulfate) deposition. In terrestrial ecosystems, acidification depletes soil nutrients and mobilizes aluminum, affecting plant health and growth. In lakes and streams, acidification harms fish, amphibians, and aquatic insects.

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

  1. Nitrogen and Sulfur 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.

Select an acidification risk assessment report using the map or list below.

Acidification Risk Assessment Network Map