Organic carbon burial efficiency in lake sediments controlled by oxygen exposure time and sediment source
Organic carbon burial efficiency in lake sediments controlled by oxygen exposure time and sediment source
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DOI：
10.4319/lo.2009.54.6.2243
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发表时间：
2009-11
影响因子：
4.5
通讯作者：
S. Sobek;E. Durisch-Kaiser;R. Zurbrügg;Nuttakan Wongfun;Martin Wessels;Natacha Pasche;B. Wehrli
中科院分区：
文献类型：
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作者：
S. Sobek;E. Durisch-Kaiser;R. Zurbrügg;Nuttakan Wongfun;Martin Wessels;Natacha Pasche;B. Wehrli
我们比较了来自11个湖泊的27种不同沉积物中有机碳的埋藏效率（埋藏OC和沉积OC），重点研究了有机质来源、氧气暴露和OC在矿物表面的保护性吸附的潜在影响。OC的平均埋藏效率较高（平均48%），在外来有机质输入量较大的沉积物中埋藏效率尤其高（平均67%）。此外，OC埋藏效率与氧暴露时间呈强烈负相关，特别是在接受高异源负荷的沉积物中。另一方面，有机碳的埋藏效率与矿物表面积无关，而矿物表面积是表征矿物相对有机碳吸附能力的指标。因此，许多湖泊沉积物的高OC埋藏效率可归因于湖泊频繁和大量的外来有机质输入，以及OC埋藏效率对氧暴露时间的强烈依赖。本研究表明，湖泊沉积物中的碳汇改变了OC从大陆向海洋的输出，湖泊沉积物中OC的命运（埋藏与矿化为二氧化碳和甲烷）对环境条件高度敏感。
We compared the burial efficiency of organic carbon (buried OC: deposited OC) in a diverse set of 27 different sediments from 11 lakes, focusing on the potential effects of organic matter source, oxygen exposure, and protective sorption of OC onto mineral surfaces. Average OC burial efficiency was high (mean 48%), and it was particularly high in sediments receiving high input of allochthonous organic matter (mean 67%). Further, OC burial efficiency was strongly negatively related to the oxygen exposure time, again particularly so in sediments receiving high allochthonous loads. On the other hand, OC burial efficiency was not related to the mineral surface area, which was used as a proxy of the sorption capacity of the mineral phase for OC. The high OC burial efficiency in many lake sediments can thus be attributed to the frequent and significant input of allochthonous organic matter to lakes, as well as to a strong dependence of OC burial efficiency on oxygen exposure time. This study demonstrates that the carbon sink in lake sediments alters the OC export from the continents to the sea and that the fate of OC in lake sediments (burial vs. mineralization to carbon dioxide and methane) is highly sensitive to environmental conditions.