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SCI论文目录 |
Long-term nitrogen addition decreases carbon leaching in a nitrogen-rich forest ecosystem |
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| 出 版 社：Biogeosciences |
| 发表时间：2013 |
| 台 站：
鼎湖山森林生态系统定位研究站
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| 作 者：鲁显楷等 |
| 点 击 率：3547 |
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| 摘 要(英文)：Dissolved organic carbon (DOC) plays a critical role in the carbon (C) cycle of forest soils, and has been recently connected with global increases in nitrogen (N) deposition. Most studies on effects of elevated N deposition on DOC have been carried out in N-limited temperate regions,with far fewer data available from N-rich ecosystems, especially in the context of chronically elevated N deposition.Furthermore, mechanisms for excess N-induced changes of
DOC dynamics have been suggested to be different between the two kinds of ecosystems, because of the different ecosystem N status. The purpose of this study was to experimentally examine how long-term N addition affects DOC dynamics below the primary rooting zones (the upper 20cm soils) in typically N-rich lowland tropical forests. We have a primary assumption that long-term continuous N addition
minimally affects DOC concentrations and effluxes in N-rich tropical forests. Experimental N addition was administered at the following levels: 0, 50, 100 and 150kgNha−1 yr−1,respectively. Results showed that seven years of N addition significantly decreased DOC concentrations in soil solution, and chemo-physical controls (solution acidity change and soil sorption) rather than biological controls may mainly account for the decreases, in contrast to other forests. We further found that N addition greatly decreased annual DOC effluxes from the primary rooting zone and increased waterextractable DOC in soils. Our results suggest that long-term
N deposition could increase soil C sequestration in the upper soils by decreasing DOC efflux from that layer in N-rich ecosystems, a novel mechanism for continued accumulation of soil C in old-growth forests. |
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 鲁显楷-2013-Biogeosciences-Long-term nitrogen addition decreases carbon leaching in a nitrogen-rich forest ecosystem.pdf |
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