Nitrogen to phosphorus ratios of tree species in response to elevated carbon dioxide and nitrogen addition in subtropical forests |
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出 版 社：Global Change Biology |
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发表时间：2013 |
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台 站：鼎湖山森林生态系统定位研究站 |
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作 者：刘菊秀，黄文娟，周国逸等
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点 击 率：581623 |
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关 键 字(英文)：carbon dioxide, N addition, N : P ratios, N2 fixer, subtropical forests |
| 摘 要(英文)：Increased atmospheric carbon dioxide (CO2) concentrations and nitrogen (N) deposition induced by human activities have greatly influenced the stoichiometry of N and phosphorus (P). We used model forest ecosystems in open-top chambers to study the effects of elevated CO2 (ca.700 lmol mol-1) alone and together with N addition
(100 kg N ha-1 yr-1) on N to P (N:P) ratios in leaves, stems and roots of five tree species, including four non-N2 fixers and one N2 fixer, in subtropical China from 2006 to 2009. Elevated CO2 decreased or had no effects on N : P ratios in plant tissues of tree species. N addition, especially under elevated CO2, lowered N : P ratios in the N2 fixer, and this effect was significant in the stems and the roots. However, only one species of the non-N2 fixers showed significantly lower N : P ratios under N addition in 2009, and the others were not affected by N addition. The reductions of N : P ratios in response to elevated CO2 and N addition were mainly associated with the increases in P concentrations. Our results imply that elevated CO2 and N addition could facilitate tree species to mitigate P limitation by more strongly influencing P dynamics than N in the subtropical forests. |
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 刘菊秀-2013-GCB-Nitrogen to phosphorus ratios of tree species in response to elevated carbon dioxide and nitrogen addition in subtropical forests.pdf |
