Elevated co2 stimulates net accumulations of carbon and nitrogen in land ecosystems：A meta-analysis |
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出 版 社：Ecology |
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发表时间：2006 |
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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：Luo Yiqi, Hui Dafeng，Zhang Deqing
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点 击 率：593012 |
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关 键 字(英文)：carbon sequestration; ecosystem development; global change; meta-analysis; nitrogen;stoichiometry. |
| 摘 要(英文)：The capability of terrestrial ecosystems to sequester carbon (C) plays a critical role in regulating future climatic change yet depends on nitrogen (N) availability. To predict long-term ecosystem C storage, it is essential to examine whether soil N becomes
progressively limiting as C and N are sequestered in long-lived plant biomass and soil organic matter. A critical parameter to indicate the long-term progressive N limitation (PNL)is net change in ecosystem N content in association with C accumulation in plant and soil pools under elevated CO2. We compiled data from 104 published papers that study C and N dynamics at ambient and elevated CO2. The compiled database contains C contents, N contents, and C:N ratio in various plant and soil pools, and root:shoot ratio. Averaged C and N pool sizes in plant and soil all significantly increase at elevated CO2 in comparison to those at ambient CO2, ranging from a 5% increase in shoot N content to a 32% increase
in root C content. The C and N contents in litter pools are consistently higher in elevated than ambient CO2 among all the surveyed studies whereas C and N contents in the other pools increase in some studies and decrease in other studies. The high variability in CO2-induced changes in C and N pool sizes results from diverse responses of various C and N processes to elevated CO2. Averaged C:N ratios are higher by 3% in litter and soil pools and 11% in root and shoot pools at elevated relative to ambient CO2. Elevated CO2 slightly increases root:shoot ratio. The net N accumulation in plant and soil pools at least helps prevent complete down-regulation of, and likely supports, long-term CO2 stimulation of C sequestration. The concomitant C and N accumulations in response to rising atmospheric CO2 may reflect intrinsic nature of ecosystem development as revealed before by studies of succession over hundreds to millions of years. |
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 Elevated co2 stimulates net accumulations of carbon and nitrogen in land ecosystems：A meta-analysis.pdf |
