Methane consumption by montane soils: Implications for positive and negative feedback with climatic change
Methane consumption by montane soils: Implications for positive and negative feedback with climatic change
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DOI：
10.1007/bf00001532
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发表时间：
1996-01-01
期刊：
影响因子：
4
通讯作者：
Harte, J
中科院分区：
文献类型：
--
作者：
Torn, MS;Harte, J
我们在此报告3年的甲烷吸收野外观测，平均1.2 mg CH4 m(-2) d（-1）在山地草甸土壤。表层土壤水分影响基质的扩散，而深层土壤中甲烷氧化作用最大，水分既影响基质的扩散，也影响微生物的活性。微生物对甲烷的氧化作用在土壤水分中等水平时达到最大，在该地点，水分重量约为25%（持水量为50%）。这些结果为甲烷氧化菌活性的水分限制提供了原位表征，并证明土壤干燥可能会降低甲烷汇强度。正如冰核数据所显示的那样，低土壤湿度下微生物对甲烷消耗的限制为甲烷通量与气候变暖之间的正反馈提供了一个机制（Blunier et al. 1993; Chappellaz et al. 1990; Stauffer et al. 1985）。
We report here three years of field observations of methane uptake, averaging 1.2 mg CH4 m(-2) d(-1) in montane meadow soils. Surface soil moisture influenced diffusion of substrate while in deeper soil, where methane oxidation was maximum, moisture influenced both diffusion and microbial activity. Microbial oxidation of methane was maximum at an intermediate level of soil moisture, at this site at about 25% moisture by weight (50% water holding capacity). Laboratory incubations also showed inhibition below 20% moisture, These results provide in situ characterization of moisture limitation of methanotroph activity and evidence that soil drying may diminish the methane sink strength. The microbial limitation to methane consumption at low soil moisture provides a mechanism for positive feedback between methane flux and climate warming, as suggested by ice core data (Blunier et al. 1993; Chappellaz et al. 1990; Stauffer et al. 1985).