Regional patterns in foliar N across a gradient of nitrogen deposition in the northeastern US
نویسندگان
چکیده
Recent studies have demonstrated that natural abundance N can be a useful tool for assessing nitrogen saturation, because as nitrification and nitrate loss increase, dN of foliage and soil also increases. We measured foliar dN at 11 high-elevation spruce-fir stands along an N deposition gradient in 1987e1988 and at seven paired northern hardwood and spruce-fir stands in 1999. In 1999, foliar dN increased from 5.2 to 0.7& with increasing N deposition from Maine to NY. Foliar dN decreased between 1987e1988 and 1999, while foliar %N increased and foliar C:N decreased at most sites. Foliar dN was strongly correlated with N deposition, and was also positively correlated with net nitrification potential and negatively correlated with soil C:N ratio. Although the increase in foliar %N is consistent with a progression towards N saturation, other results of this study suggest that, in 1999, these stands were further from N saturation than in 1987e1988. Published by Elsevier Ltd.
منابع مشابه
Regional patterns in foliar (15)N across a gradient of nitrogen deposition in the northeastern US.
Recent studies have demonstrated that natural abundance (15)N can be a useful tool for assessing nitrogen saturation, because as nitrification and nitrate loss increase, delta(15)N of foliage and soil also increases. We measured foliar delta(15)N at 11 high-elevation spruce-fir stands along an N deposition gradient in 1987-1988 and at seven paired northern hardwood and spruce-fir stands in 1999...
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