Is Nitrogen Deposition Altering the Nitrogen Status of Northeastern Forests?

Concern is resurfacing in the United States over the long-term effects of excess nitrogen (N) deposition and mobility in the environment. We present here a new synthesis of existing data sets for the northeastern United States, intended to answer a single question: Is N deposition altering the N status of forest ecosystems in this region? Surface water data suggest a significant increase in nitrate losses with N deposition. Soil data show an increase in nitrification with decreasing ratio of soil carbon to nitrogen (C:N) but weaker relationships between N deposition and soil C:N ratio or nitrification. Relationships between foliar chemistry and N deposition are no stronger than with gradients of climate and…

• UE
  U.S. Environmental Protection Agency
• UD
  U.S. Department of Agriculture
• SU
  Syracuse University
• WV
  West Virginia University
• UG
  U.S. Geological Survey
• UF
  U.S. Forest Service