河流碳输移与陆地侵蚀-沉积过程关系的研究进展

Correlation between riverine carbon transport and terrestrial erosion-deposition processes

河流碳输移与陆地侵蚀-沉积过程紧密相关。首先就机械和化学风化两种不同的陆地侵蚀机制在提供河流碳源方面所发挥的不同作用作了详细论述,并比较了季风流域和非季风流域间河流碳输移在通量及性质上的差异。之后对陆地碳沉积机制进行了归纳,指出了包括大坝截留,河漫滩、河口-近岸带沉积及陆地碳沉降等几种可能的陆源碳踪迹。陆地环境的截留效应相对于侵蚀尚不太清楚,今后应加强对陆地碳沉积的研究,进一步明确各种碳沉积的作用机制及其对全球陆地碳汇的贡献量。此外,人类活动对陆地侵蚀-沉积过程及河流碳循环所产生的直接或间接的影响也有待于今后继续深入探索。

The riverine carbon transport is closely related to the processes of terrestrial erosion-deposition. This paper firstly reviews two different kinds of terrestrial erosion （the mechanical and chemical weathering mechanisms）, discusses their respective roles in providing carbon to the river, and compares the differences between the monsoon and non-monsoon drainage basins in flux and the characteristic of the riverine carbon transport. Then it makes a summary of the terrestrial carbon deposition and points out several potential land-origin carbon traces including dam capture, deposition happening in floodplain, estuary and near-shore area, and terrestrial carbon precipitation. It is necessary to pay more attention to the terrestrial carbon deposition, and set up clear mechanisms of different types of carbon deposition and their respective contributions to world terrestrial carbon sink, because the captive effect of terrestrial environment relative to the terrestrial erosion is unclear. In addition, we should further explore direct or indirect impacts of human activities on the processes of terrestrial erosion-deposition and the riverine carbon cycle.