文献类型：期刊文献

英文题名：Multi-scale temporal variation in methane emission from an alpine peatland on the Eastern Qinghai-Tibetan Plateau and associated environmental controls

作者：Peng, Haijun Guo, Qian Ding, Hanwei Hong, Bing Zhu, Yongxuan Hong, Yetang Cai, Cheng Wang, Yu Yuan, Linggui

第一作者：Peng, Haijun

通信作者：Hong, B[1];Hong, B[2];Hong, B[3]

机构：[1]Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Guizhou, Peoples R China;[2]Chinese Flux Observat & Res Network, Bayinbuluk Alpine Wetland Res Stn, Beijing, Peoples R China;[3]Univ Chinese Acad Sci, Beijing 100049, Peoples R China;[4]CAS Ctr Excellence Quaternary Sci & Global Change, Xian 710061, Shaanxi, Peoples R China;[5]Guizhou Inst Technol, Sch Chem Engn, Guiyang 550055, Guizhou, Peoples R China

第一机构：Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Guizhou, Peoples R China

通信机构：corresponding author), Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Guizhou, Peoples R China;corresponding author), Chinese Flux Observat & Res Network, Bayinbuluk Alpine Wetland Res Stn, Beijing, Peoples R China;corresponding author), CAS Ctr Excellence Quaternary Sci & Global Change, Xian 710061, Shaanxi, Peoples R China.

年份：2019

卷号：276

外文期刊名：AGRICULTURAL AND FOREST METEOROLOGY

收录：;Scopus(收录号：2-s2.0-85067227101);WOS:【SCI-EXPANDED(收录号:WOS:000500195900014)】；

基金：This research was financially supported by the National Natural Science Foundation of China (grant numbers: 41373134, 41573012, and 41673119), the Strategic Pilot Science and Technology Projects of the Chinese Academy of Sciences (XDA05120501), and the Chinese Academy of Sciences' "Light of West China" Program. Special thanks to the two anonymous reviewers for their valuable comments on the original manuscript.

语种：英文

外文关键词：Methane Emission; Eddy Covariance; Alpine Peatland; Wavelet Analysis; Qinghai-Tibetan Plateau; Temporal Variation

摘要：Most previous studies on methane (CH4) emissions from peatlands have focused on the boreal, subarctic, and tropical regions. Little is known about CH4 emissions from the alpine peatlands that are widely distributed in the eastern Qinghai-Tibetan Plateau (QTP), which are sensitive to climate change and human disturbance. To assess the magnitudes of daily and seasonal variations in CH4 flux in this area, and to identify the influential environmental factors, an eddy covariance (EC) tower with a LI-7700 open-path CH4 analyzer was established on Hongyuan Peatland. Total annual CH4 emission was 46.8 g CH(4)m(-2) in 2014, with emissions in the non-growing season accounting for 25% of the annual total. From May to September 2014, diurnal variation in CH4 emissions was observed, with CH4 fluxes varying between 0.15 and 0.25 mu molm(-2) s(-1). In contrast, during all other periods of 2014, no diurnal variation was observed, and CH4 flux varied below 0.05 mu mol m(-2) s(-1). A clear seasonal pattern in CH4 exchange with small surges in CH4 emission appeared in soil thawing and freezing seasons. Wavelet analysis was applied to the continuous CH4 flux time series to explore temporal variation in ecosystem CH4 exchange during the growing season. On daily timescales, changes in CH4 flux are in phase with changes in air temperature, and influenced by friction velocity and vapor pressure deficit (VPD). On weekly-to-monthly timescales, soil temperature can explain most of the variation in CH4 exchange. Though CH4 fluxes had no apparent correlation with water table level, fluxes were significantly (R-2 = 0.86) correlated with soil temperature measured at -25 cm depth, close to the water table level throughout the growing season, suggesting a synergistic effect of water table level and soil temperature on methane emission. This study highlights the need for continuous eddy covariance measurements and time series analysis approaches to adequately describe temporal variability in ecosystem CH4 exchange.