PATHWAYS OF ORGANIC-CARBON OXIDATION IN 3 CONTINENTAL-MARGIN SEDIMENTS
PATHWAYS OF ORGANIC-CARBON OXIDATION IN 3 CONTINENTAL-MARGIN SEDIMENTS
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DOI：
10.1016/0025-3227(93)90147-n
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发表时间：
1993-07-01
期刊：
影响因子：
2.9
通讯作者：
HALL, POJ
中科院分区：
文献类型：
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作者：
CANFIELD, DE;JORGENSEN, BB;HALL, POJ
我们结合了几种不同的方法来量化有机碳矿化率的各种电子受体沉积物从丹麦和挪威的海岸。NH 4+和SIGMACO 2释放率在沉积物培养中使用与O2渗透深度得出的结论是，O2呼吸只占总有机碳氧化的3.6-17.4%。脱entrification仅限于一个狭窄的区域，低于O2渗透的深度，并不是一个主要的碳氧化途径。Fe还原、Mn还原和硫酸盐还原过程是有机碳矿化的主导过程，但其相对重要性因沉积物而异。当发现高浓度的Mn氧化物（3- 4wt%Mn）时，仅发生Mn还原。与较低的锰氧化物浓度更典型的沿海沉积物，铁还原和硫酸盐还原是最重要的和相似的幅度。总体而言，大部分的O2通量测量到的沉积物被用来氧化还原无机物种，而不是有机碳。我们怀疑在许多沿海沉积物中O2呼吸的重要性被高估了，而金属氧化物还原（Fe和Mn还原）可能被低估了。
We have combined several different methodologies to quantify rates of organic carbon mineralization by the various electron acceptors in sediments from the coast of Denmark and Norway. Rates of NH4+ and SIGMACO2 liberation in sediment incubations were used with O2 penetration depths to conclude that O2 respiration accounted for only between 3.6-17.4% of the total organic carbon oxidation. Dentrification was limited to a narrow zone just below the depth of O2 penetration, and was not a major carbon oxidation pathway. The processes of Fe reduction, Mn reduction and sulfate reduction dominated organic carbon mineralization, but their relative significance varied depending on the sediment. Where high concentrations of Mn-oxide were found (3-4 wt% Mn), only Mn reduction occurred. With lower Mn oxide concentrations more typical of coastal sediments, Fe reduction and sulfate reduction were most important and of a similar magnitude. Overall, most of the measured O2 flux into the sediment was used to oxidized reduced inorganic species and not organic carbon. We suspect that the importance Of O2 respiration in many coastal sediments has been overestimated, whereas metal oxide reduction (both Fe and Mn reduction) has probably been well underestimated.