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SCI论文目录 |
鼎湖山土壤有机质δ13C 时空分异机制 |
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| 出 版 社：应用生态学报 |
| 发表时间：2005 |
| 台 站：
鼎湖山森林生态系统定位研究站
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| 作 者：陈庆强，沈承德，孙彦敏，彭少麟，易惟熙，李志安，姜漫涛 |
| 点 击 率：50881 |
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| 关 键 字：土壤有机质,碳同位素,碳循环,亚热带,鼎湖山 |
| 摘 要：根据鼎湖山若干海拔部位土壤剖面薄层取样样品有机质含量、14C测年及δ13C 结果,研究土壤有机质δ13C 时空分异机制. 结果表明,不同海拔土壤剖面有机质δ13C 深度特征受控于剖面发育进程,与有机质组成及其分解过程密切相关. 植被枯落物成为表土层有机质以及表土层被埋藏后的有机质更新过程,均存在碳同位素分馏效应,有机质δ13C 显著增大. 相对于地表植被枯落物δ13C ,表土层有机质δ13C 增幅取决于表土有机质更新速率. 表土有机质δ13C 与植被枯落物δ13C 均随海拔升高而增大,说明植被构成随海拔升高呈规律性变化. 这与鼎湖山植被的垂直分布一致. 不同海拔土壤剖面有机质δ13C2深度特征类似,有机质含量深度特征一致,有机质14C 表观年龄自上向下增加. 这是剖面发育过程中有机质不断更新的结果.土壤剖面有机质δ13C 最大值深度与14C弹穿透深度的成因和大小不同,均反映地貌与地表植被对有机碳同位素深度分布的控制. |
| 关 键 字(英文)：Soil organic matter , 14C , Carbon cycling , Subtropical zone , Dinghushan Biosphere Reserve. |
| 摘 要(英文)：Based on the determinations of soil organic matter (SOM) content ,SOMΔ 14C ,and SOMδ13C of the samples collected by thin2layered sampling method ,this paper studied the spatial and temporal differentiation of SOMδ13C in the soil profiles at different altitudes in Dinghushan Biosphere Reserve. The results showed that the vertical
differentiation of SOMδ13 C at different altitudes was controlled by the development of soil profile ,and closely
correlated with the composition of SOM and its turnover processes. The fractionation of carbon isotope was hap2
pened during both the transformation of vegetation debris into topsoil organic matter (OM) and its regeneration
after the topsoil buried ,which resulted in a significant increase of SOMδ13C. Relative to plant debrisδ13C ,theδ13
C increment of topsoil OM was more dependent on its turnover rate.Both theδ13C of plant debris and topsoil OM
increased with altitude ,indicating the regular variation of vegetations with altitude ,which was consensus to the
vertical distribution of vegetations in Dinghushan Biosphere Reserve. Soil profiles at different altitudes had similar
characteristics in vertical differentiation of SOMδ13C ,vertical distribution of SOM content ,and increasing appar2
ent age of SOM 14C with soil depth ,which were resulted from the successive turnover of SOM during the devel2
opment of soil profile. The maximum depth of SOMδ13 C in soil profile was different in origin and magnitude with the penetration depth of 14C produced by nuclear explosion in the atmosphere ,indicating the controlling effects of topography and vegetation on the distribution of SOM carbon isotope with soil depth. |
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 鼎湖山土壤有机质δ～13C时空分异机制_2005 应用生态学报 彭少麟.pdf |
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