Carbon isotope and C/N ratios of suspended matter in rivers:: an indicator of seasonal change in C4/C3 vegetation
Carbon isotope and C/N ratios of suspended matter in rivers:: an indicator of seasonal change in C4/C3 vegetation
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DOI：
10.1016/s0883-2927(02)00249-4
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发表时间：
2003-08-01
影响因子：
3.4
通讯作者：
Cai, DL
中科院分区：
文献类型：
--
作者：
Liu, WB;An, ZS;Cai, DL
利用δ C-13值与悬浮物C/N比值的组合，研究了黄土高原C-4和C-3植被的季节关系。河流悬浮物C同位素组成与C/N比值可以区分土壤和植物物质，并可用于估算土壤有机C和植物凋落物对悬浮物的相对贡献。碳同位素组成与碳氮比的关系表明，样品是两端成员的混合体：(1)δ C-13值相对恒定，低碳含量和低碳氮比的现代土壤；(2)不同δ C-13值、高碳含量和高碳氮比的凋落物。研究结果反映了黄土高原地区C-4/C-3植被的季节分布。黄土高原东部夏季植被生态系统中C-4草的丰度约为20%。因此，使用δ C-13值和河流和现代土壤中悬浮物的C/N比值可能有助于反映集水区C-4/C-3植被的季节分布。这可能是区分用于地理信息系统研究的集水区和用于集水区生态管理的长期规划的有用工具。2003爱思唯尔科学有限公司版权所有。
A combination of delta C-13 values with C/N ratios in suspended matter has been used to examine the seasonal relationship between C-4 and C-3 vegetation along the Loess Plateau, NW China. The C isotopic composition of suspended organic matter in rivers, together with C/N ratios can differentiate between soil and plant material, and can be used to estimate the relative contributions of soil organic C and plant litter to the suspended matter. The relationship between C isotopic composition and C/N ratios indicates that the samples are a mixture of two end members: (1) modern soils with relatively constant delta C-13 values, low C content and low C/N ratios; (2) plant litter with varying delta C-13 values, high C content and high C/N ratios. The results reflect the seasonal distribution of C-4/C-3 vegetation within the area studied, as part of the Loess Plateau. The abundance Of C-4 grasses is about 20% for the current summer vegetation ecosystem in the eastern part of the Loess Plateau. Hence, the use of delta C-13 values and C/N ratios of suspended matter in rivers and modern soil may be useful for reflecting seasonal distribution of C-4/C-3 vegetation in catchments. This could be a useful tool for distinguishing between catchments for GIS studies, and long term planning for ecological management of catchment areas. (C) 2003 Elsevier Science Ltd. All rights reserved.