SOIL EROSION AND CARBON DYNAMICS
SOIL EROSION AND CARBON DYNAMICS
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DOI：
10.1097/01.ss.0000235848.71191.7c
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
J. Kimble
中科院分区：
文献类型：
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作者：
J. Kimble
加速侵蚀涉及土壤有机碳（SOC）的优先去除，因为它集中在土壤表面附近，密度低于矿物部分。由径流输送的有机碳在景观中重新分布，并沉积在洼地，与沉积物一起沿着埋藏。然而，由侵蚀过程输送、重新分配和沉积的SOC的命运是一个激烈争论的主题。沉积学家认为，与沉积物一起埋藏的SOC受到物理保护，而在侵蚀土壤中耗尽的SOC则通过生物质生产来替代。因此，他们认为侵蚀-沉积过程导致全球净SOC固存为0.6-1.5 Gt C/年。相反，土壤科学家认为：（i）由水径流输送的大部分SOC包括不稳定部分，（ii）由雨滴冲击和径流剪切力引起的聚集体的分解加剧了先前受保护的有机物质的矿化，以及（iii）在沉积地点的耕作区内的SOC可能受到快速矿化，沿着厌氧环境下的产甲烷和反硝化。而耕作侵蚀也可能导致部分SOC的埋藏，土壤侵蚀的增加和化石燃料燃烧产生的CO2排放是大气CO2的净来源。土壤科学家认为，土壤侵蚀可能是大气CO2的净来源，每年排放1千兆吨碳。因此，重要的是要了解的侵蚀SOC的命运，通过测量和监测土壤有机碳库侵蚀景观的强度和频率的耕作作业和种植制度的影响。# 2004 Elsevier B. V.保留所有权利。
Accelerated erosion involves preferential removal of soil organic carbon (SOC) because it is concentrated in vicinity of the soil surface and has lower density than the mineral fraction. The SOC transported by water runoff is redistributed over the landscape and deposited in depressional sites where it is buried along with the sediments. However, the fate of the SOC transported, redistributed and deposited by erosional processes is a subject of intense debate. Sedimentologists argue that SOC buried with sediments is physically protected, and that depleted in the eroded soil is replaced through biomass production. Thus, they argue that the erosion–sedimentation process leads to globally net SOC sequestration of 0.6–1.5 Gt C/year. In contrast, soil scientists argue that: (i) a large portion of the SOC transported by water runoff comprises labile fraction, (ii) breakdown of aggregation by raindrop impact and shearing force of runoff accentuates mineralization of the previously protected organic matter, and (iii) the SOC within the plow zone at the depositional sites may be subject to rapid mineralization, along with methanogenesis and denitrification under anaerobic environment. Whereas, tillage erosion may also cause burial of some SOC, increase in soil erosion and emission of CO2 from fossil fuel combustion are net sources of atmospheric CO2. Soil scientists argue that soil erosion may be a net source of atmospheric CO2 with emission of 1 Gt C/year. It is thus important to understand the fate of eroded SOC by measuring and monitoring SOC pool in eroded landscape as influenced by intensity and frequency of tillage operations and cropping systems. # 2004 Elsevier B.V. All rights reserved.