Methane emissions from an alpine wetland on the Tibetan Plateau: Neglected but vital contribution of the nongrowing season

The vast wetlands on the Tibetan Plateau are expected to be an important natural source of methane (CH4) to the atmosphere. The magnitude, patterns and environmental controls of CH4 emissions on different timescales, especially during the nongrowing season, remain poorly understood, because of techn...

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Bibliographic Details
Published in:Journal of Geophysical Research: Biogeosciences
Main Authors: Song, Weimin, Wang, Hao, Wang, Guangshuai, Chen, Litong, Jin, Zhenong, Zhuang, Qianlai, He, Jin-Sheng
Other Authors: He, JS (reprint author), Peking Univ, Coll Urban & Environm Sci, Dept Ecol, Beijing 100871, Peoples R China., Peking Univ, Coll Urban & Environm Sci, Dept Ecol, Beijing 100871, Peoples R China., Peking Univ, Minist Educ, Key Lab Earth Surface Proc, Beijing 100871, Peoples R China., Chinese Acad Sci, Key Lab Adaptat & Evolut Plateau Biota, Northwest Inst Plateau Biol, Xining, Peoples R China., Purdue Univ, Dept Earth Atmospher & Planetary Sci, W Lafayette, IN 47907 USA., Purdue Univ, Dept Agron, W Lafayette, IN 47907 USA.
Format: Journal/Newspaper
Language:English
Published: JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES 2015
Subjects:
Online Access:https://hdl.handle.net/20.500.11897/417372
https://doi.org/10.1002/2015JG003043
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Summary:The vast wetlands on the Tibetan Plateau are expected to be an important natural source of methane (CH4) to the atmosphere. The magnitude, patterns and environmental controls of CH4 emissions on different timescales, especially during the nongrowing season, remain poorly understood, because of technical limitations and the harsh environments. We conducted the first study on year-round CH4 fluxes in an alpine wetland using the newly developed LI-COR LI-7700 open-path gas analyzer. We found that the total annual CH4 emissions were 26.4 and 33.8 g CH(4)m(-2) in 2012 and 2013, respectively, and the nongrowing season CH4 emissions accounted for 43.2-46.1% of the annual emissions, highlighting an indispensable contribution that was often overlooked by previous studies. A two-peak seasonal variation in CH4 fluxes was observed, with a small peak in the spring thawing period and a large one in the peak growing season. We detected a significant difference in the diurnal variation of CH4 fluxes between the two seasons, with two peaks in the growing season and one peak in the nongrowing season. We found that the CH4 fluxes during the growing season were well correlated with soil temperature, water table depth and gross primary production, whereas the CH4 fluxes during the nongrowing season were highly correlated with soil temperature. Our results suggested that the CH4 emission during the nongrowing season cannot be ignored and the vast wetlands on the Tibetan plateau will have the potential to exert a positive feedback on climate considering the increasing warming, particularly in the nongrowing season in this region. National Natural Science Foundation of China [31270481, 31321061]; National Program on Key Basic Research Project [2014CB954004]; Program of "One Hundred Talented People" of the Chinese Academy of Sciences [KSCX2-YW-Z-0806] SCI(E) ARTICLE jshe@pku.edu.cn 8 1475-1490 120