增江流域河流颗粒有机碳的来源、含量变化及输出通量

The sources, seasonal variation and transported fluxes of the riverine particulate organic carbon of the Zengjiang River, Southern China

对华南增江径流进行了 1个水文年度的 1 5次等时段采样 ,分析了河流悬移质中主要生源元素 (C、N、H)的含量 ,并估算了不同物源的贡献 .结果表明 ,增江悬移质中的有机碳以水生藻类的贡献为主 ,土壤侵蚀来源的有机碳在悬移质粗粒组中的份额平均为 37 2 4 % ,在细粒组中仅占 1 1 1 1 % 增江流域颗粒有机碳的输出通量为 0 83× 1 0 6g·km-2 ·a-1 ,其中来自土壤的颗粒有机碳通量为 0 2 2× 1 0 6g·km-2 ·a-1 .

The transfer of carbon from land to sea via rivers represents a major link in the global carbon cycle. The Zengjiang River drainage, a second-classed tributary of the Zhujiang (Pearl) River drainage, lies in the subtropical monsoon area, southern China, with the Tropic of Cancer through it. Suspended sediments had been collected for four weeks from the Zengjiang River and represent for a whole hydrological year. The main biogenic elements, including carbon, nitrogen and hydrogen were analyzed, and two major potential contributions from soil organic matter and aquatic algae were estimated. The research results indicated that the organic carbon in the suspended sediments originates mainly from primary production, and that from the soil organic carbon represented only 37.24% for the coarse sediments and even less 11.11% for the fine sediments. The transported particulate organic carbon flux in the Zengjiang River drainage amounts to 0.83×10~6?g·km^(-2)·a^(-1), in which that comes from soil erosion processes is 0.22×10~6?g·km^(-2)·a^(-1).