USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Research Topics

Air Quality: Nitrogen Cycling

[Map]: Map of throughfall sampling sites in California Chronic high N deposition to the normally N-limited systems of California is a major ecological perturbation. Long-term effects are unknown - but exacerbation of multiple stress effects (e.g., drought, ozone, insects, disease, competition, mycorrhizal impairment) is of concern. Our research has found that N cycling rates are greatly accelerated, resulting in elevated fluxes of NO3 and NO into the atmosphere. Of particular concern is water quality degradation (high nitrates) that we have found in watersheds with high pollutant exposure. These watersheds provide drinking water for major urban areas.
[Photo]: Inexpensive ion exchange resin collumn A full evaluation of air pollution effects on ecosystems requires an estimate of total deposition fluxes. Collection of throughfall, the hydrologic flux of nutrients from the canopy to the forest floor, is widely acknowledged as a practical method of monitoring atmospheric deposition to forests. We have developed a "passive" throughfall collector in which the deposition is captured in ion exchange resin columns. This method of throughfall collection is much less expensive than tradition methods and provides an opportunity to quantify nitrogen and sulfur deposition at a greater number of sites than previously possible. Using this method we are increasing our understanding of what nitrogen deposition inputs cause various effects on forests throughout California.

Research is being conducted by:
  • Air Pollution and Global Change Impacts on Western Forest Ecosystems (RWU-4451)

  • Last Modified: Mar 28, 2013 03:39:02 PM