Trophic status impacts both the magnitude and stable carbon isotope composition of methane flux from peatlands
Trophic status impacts both the magnitude and stable carbon isotope composition of methane flux from peatlands
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DOI：
10.1029/2007gl031231
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发表时间：
2007-11-02
影响因子：
5.2
通讯作者：
Bowes, Helen L.
中科院分区：
文献类型：
--
作者：
Hornibrook, Edward R. C.;Bowes, Helen L.
在英国威尔士两个富营养泥炭地和两个微营养泥炭地，研究了营养状况对甲烷的产生、排放和稳定碳同位素组成的影响。微营养泥炭地甲烷的产生和排放速率最高，孔隙水中的甲烷和向大气排放的甲烷都显著地富含(13)C。酸性降雨泥炭地CH(4)通量的高度负的(13)C值(-95%~-82%)可能是由于CO(2)/H(2)的甲烷化作用和与CH(4)通过维管植物的透气组织扩散有关的同位素效应的共同作用。目前在甲烷(4)循环的同位素加权质量平衡收支中归因于来自北部湿地的甲烷(4)通量的增量(13)C值可能太正了。北部沼泽和沼泽的甲烷通量应该被赋予不同的(13)C值，因为前者的甲烷(4)明显更多地被(13)C消耗，尽管排放强度通常较弱。
The influence of trophic status on CH(4) production, emission and stable carbon isotope composition was investigated in two ombrogenous and two minerotrophic peatlands situated in Wales, UK. Methane production and emission rates were highest in the minerotrophic peatlands and CH(4) in both pore water and emissions to the atmosphere were notably (13)C-enriched compared to the ombrogenous bogs. Highly negative delta(13) C values (- 95 to -82%) for CH(4) flux from the acidic rainfed peatlands likely resulted from a combination of CO(2)/H(2) methanogenesis and isotope effects associated with diffusion of CH(4) through aerenchymatous tissue of vascular flora. The delta(13) C values presently attributed to CH(4) flux from northern wetlands in isotope-weighted mass balance budgets of the CH(4) cycle may be too positive. Methane flux from northern bogs and fens should be assigned different delta(13) C values because CH(4) is notably more (13)C-depleted in the former, albeit emission strength typically is weaker.