The effect of peat structure on the spatial distribution of biogenic gases within bogs
The effect of peat structure on the spatial distribution of biogenic gases within bogs
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DOI：
10.1002/hyp.10056
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发表时间：
2014-10
影响因子：
3.2
通讯作者：
X. Comas;N. Kettridge;A. Binley;L. Slater;A. Parsekian;A. J. Baird;M. Strack;J. Waddington
中科院分区：
文献类型：
--
作者：
X. Comas;N. Kettridge;A. Binley;L. Slater;A. Parsekian;A. J. Baird;M. Strack;J. Waddington
北方泥炭地是大气甲烷（CH 4）的主要来源，同时也是大气二氧化碳（CO 2）的源和汇。气体与泥炭土交换的速率和时间变化与泥炭柱内这些自由相气体的空间分布直接相关。在本文中，我们介绍了地面和钻孔探地雷达测量的结果-直接土壤和气体采样的约束-比较了两个凸起沼泽中天然气聚集的空间分布：一个在威尔士（英国），另一个在缅因州（美国）。虽然这两个泥炭地具有相似的平均厚度，泥炭基质的物理性质不同，特别是在泥炭类型和腐殖化程度方面。我们假设，这些物理性质的变化是造成两个泥炭地之间气体分布差异的原因，其特征在于：（1）在驯鹿沼泽（缅因州），木质泥炭和木材层的存在下，气体含量高达10.8%;（2）在Cors Fochno（威尔士），气体含量在表面（即<0.5 m深）更均匀的分布高达5.7%。我们的研究结果突出了泥炭地生物气积累和分布的变异性，并表明泥炭基质的性质在定义生物气如何在泥炭土中积累和释放到大气中具有关键作用。© 2015作者。出版社：John Wiley & Sons Ltd
Northern peatlands are a large source of atmospheric methane (CH4) and both a source and a sink of atmospheric carbon dioxide (CO2). The rate and temporal variability in gas exchanges with peat soils is directly related to the spatial distribution of these free‐phase gases within the peat column. In this paper, we present results from surface and borehole ground‐penetrating radar surveys – constrained with direct soil and gas sampling – that compare the spatial distribution of gas accumulations in two raised bogs: one in Wales (UK), the other in Maine (USA). Although the two peatlands have similar average thickness, physical properties of the peat matrix differ, particularly in terms of peat type and degree of humification. We hypothesize that these variations in physical properties are responsible for the differences in gas distribution between the two peatlands characterized by (1) gas content up to 10.8% associated with woody peat and presence of wood layers in Caribou Bog (Maine) and (2) a more homogenous distribution with gas content up to 5.7% at the surface (i.e. <0.5 m deep) in Cors Fochno (Wales). Our results highlight the variability in biogenic gas accumulation and distribution across peatlands and suggest that the nature of the peat matrix has a key role in defining how biogenic gas accumulates within and is released to the atmosphere from peat soils. © 2015 The Authors. Hydrological Processes published by John Wiley & Sons Ltd.