文章基本信息

标题：Depth Distribution of Net Methanotrophic Activity at a Mountain Birch Forest—Tundra Heath Ecotone, Northern Sweden
其他标题：Depth Distribution of Net Methanotrophic Activity at a Mountain Birch Forest—Tundra Heath Ecotone, Northern Sweden
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作者：Sofie Sjögersten ; Erik Melander ; Philip A. Wookey 等
期刊名称：Arctic, Antarctic, and Alpine Research
印刷版ISSN：1523-0430
电子版ISSN：1938-4246
出版年度：2007
卷号：39
期号：3
页码：477-480
DOI：10.1657/1523-0430(06-009)[SJOGERSTEN]2.0.CO%3B2
摘要：Methanotrophy (the bacterial oxidation of CH 4 ) in soils is the major biological sink for atmospheric CH 4 . Here we present results from a study designed to quantify the role of the physical diffusion barrier to CH 4 , through surface soils, as a factor affecting methanotrophy. We used the mountain birch forest–tundra heath ecotone in subarctic northern Sweden as our study system. Our results show that, although CH 4 fluxes were generally low (around −20 µmol m −2 h −1 ; a net flux from atmosphere to soil), the two adjacent communities responded in contrasting ways to in situ experimental reduction of the diffusion barrier (removal of the top 50 mm of soil): Uptake increased by 40% in forest soil in association with the removal, whereas it decreased marginally (by 10%) in tundra heath. Investigations of the depth-distribution of CH 4 oxidation in vitro revealed maximum rates at the top of the mineral soil for the forest site, whereas at the tundra heath this was more evenly spread throughout the organic horizon. The contrasting physicochemical properties and methanotroph activity in the organic horizons together explain the contrasting responses to the removal treatment. They also illustrate the potential role of vegetation for methane oxidation around this ecotone, exerted through its influence on the depth and properties of the organic horizons in these subarctic soils.