|Venterea, Rodney - Rod|
Submitted to: Trans American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/2003
Publication Date: 12/10/2003
Citation: Venterea, R.T., Groffman, P.M., Verchot, L., Magill, A., Aber, J., Fernandez, I., Adams, M.B., Castro, M., Lovett, G. 2003. Nitrogen oxide trace gas efflux and soil N dynamics in response to N inputs in temperate forests of the northeastern U.S. Trans American Geophysical Union. 84(46) Abstract B32B-0385. Interpretive Summary:
Technical Abstract: Forests in the northeastern U.S. continue to receive elevated inputs of nitrogen (N) in the form of atmospheric deposition. N deposition rates in this region have remained essentially constant over the past decade. Persistent N inputs to temperate forests may have impacts on local water quality, regional air quality, and the capacity of forest productivity to increase in response to increasing atmospheric carbon dioxide. Responses that become evident at the ecosystem scale may be traceable to process-level alterations in N cycling within the forest soil. During 2000 - 2001, we measured soil N cycling rates and soil-to-atmosphere exchange of N oxide trace gases at five forest sites situated along a gradient in atmospheric N deposition from West Virginia to Maine. Four of the five sites were located within long-term N addition studies. The most consistent response was an elevation in soil nitric oxide (NO) emissions, which we measured using closed-chambers. We found evidence that differences in predominant forest vegetation and/or land-use history may have resulted in differential responses with respect to NO emissions and also enhanced rates of gross and net nitrification. The data also supported the idea that atmospheric deposition of N and acidity may both combine synergistically to promote elevated rates of NO emissions due to a sequence of soil biotic and abiotic reactions.