30 Years of Nitrogen Fertilization in Spruce-Fir Forest

Rocks and sediments bind up almost 98 percent of all nitrogen. The remaining 2 percent is in motion, part of a global chemical cycle that includes humans, bacteria, plants, and the atmosphere. “Plants need nitrogen to grow,” says U.S. Forest Service research ecologist Steve McNulty. “However, excess nitrogen can harm plants.” Nitrogen and sulfur can…  More 

After the Acid Rain

“Rain has become much less acidic since the Clean Air Act was strengthened in the 1990s,” says U.S. Forest Service Southern Research Station (SRS) soil scientist Jennifer Knoepp. “However, some high elevation streams still have chronic or episodic acidity.” Acid rain, as well as other forms of acidic deposition such as acid fog and acid…  More