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Changes in Methane Flux along a Permafrost Thaw Sequence on the Tibetan Plateau.

Authors :
Guibiao Yang
Yunfeng Peng
Olefeldt, David
Yongliang Chen
Guanqin Wang
Fei Li
Dianye Zhang
Jun Wang
Jianchun Yu
Li Liu
Shuqi Qin
Tianyang Sun
Yuanhe Yang
Source :
Environmental Science & Technology. 2/6/2018, Vol. 52 Issue 3, p1244-1252. 9p.
Publication Year :
2018

Abstract

Permafrost thaw alters the physical and environmental conditions of soil and may thus cause a positive feedback to climate warming through increased methane emissions. However, the current knowledge of methane emissions following thermokarst development is primarily based on expanding lakes and wetlands, with upland thermokarst being studied less often. In this study, we monitored the methane emissions during the peak growing seasons of two consecutive years along a thaw sequence within a thermo-erosion gully in a Tibetan swamp meadow. Both years had consistent results, with the early and midthaw stages (3 to 12 years since thaw) exhibiting low methane emissions that were similar to those in the undisturbed meadow, while the emissions from the late thaw stage (20 years since thaw) were 3.5 times higher. Our results also showed that the soil water-filled pore space, rather than the soil moisture per se, in combination with the sand content, were the main factors that caused increased methane emissions. These findings differ from the traditional view that upland thermokarst could reduce methane emissions owing to the improvement of drainage conditions, suggesting that upland thermokarst development does not always result in a decrease in methane emissions. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
0013936X
Volume :
52
Issue :
3
Database :
Academic Search Index
Journal :
Environmental Science & Technology
Publication Type :
Academic Journal
Accession number :
129182605
Full Text :
https://doi.org/10.1021/acs.est.7b04979