气候变化领域集成服务门户(CCPortal): Consumption of atmospheric methane by the Qinghai-Tibet Plateau alpine steppe ecosystem

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DOI	10.5194/tc-12-2803-2018
	Consumption of atmospheric methane by the Qinghai-Tibet Plateau alpine steppe ecosystem
	Yun H.; Wu Q.; Zhuang Q.; Chen A.; Yu T.; Lyu Z.; Yang Y.; Jin H.; Liu G.; Qu Y.; Liu L.
发表日期	2018
ISSN	19940416
卷号	12 期号:9
英文摘要	The methane (CH4) cycle on the Qinghai-Tibet Plateau (QTP), the world's largest high-elevation permafrost region, is sensitive to climate change and subsequent freezing and thawing dynamics. Yet, its magnitudes, patterns, and environmental controls are still poorly understood. Here, we report results from five continuous year-round CH4 observations from a typical alpine steppe ecosystem in the QTP permafrost region. Our results suggest that the QTP permafrost region was a CH4 sink of g'0.86±0.23 g CH4-C mg'2 yrg'1 over 2012-2016, a rate higher than that of many other permafrost areas, such as the Arctic tundra in northern Greenland, Alaska, and western Siberia. Soil temperature and soil water content were dominant factors controlling CH4 fluxes; however, their correlations changed with soil depths due to freezing and thawing dynamics. This region was a net CH4 sink in autumn, but a net source in spring, despite both seasons experiencing similar top soil thawing and freezing dynamics. The opposite CH4 source-sink function in spring versus in autumn was likely caused by the respective seasons' specialized freezing and thawing processes, which modified the vertical distribution of soil layers that are highly mixed in autumn, but not in spring. Furthermore, the traditional definition of four seasons failed to capture the pattern of the annual CH4 cycle. We developed a new seasonal division method based on soil temperature, bacterial activity, and permafrost active layer thickness, which significantly improved the modeling of the annual CH4 cycle. Collectively, our findings highlight the critical role of fine-scale climate freezing and thawing dynamics in driving permafrost CH4 dynamics, which needs to be better monitored and modeled in Earth system models. © Author(s) 2018.
学科领域	active layer; atmospheric gas; climate change; freezing; methane; permafrost; soil temperature; soil water; steppe; thawing; tundra; vertical distribution; water content; Alaska; Arctic; China; Greenland; Qinghai-Xizang Plateau; Siberia; United States; Bacteria (microorganisms)
语种	英语
scopus关键词	active layer; atmospheric gas; climate change; freezing; methane; permafrost; soil temperature; soil water; steppe; thawing; tundra; vertical distribution; water content; Alaska; Arctic; China; Greenland; Qinghai-Xizang Plateau; Siberia; United States; Bacteria (microorganisms)
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119072
作者单位	State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu, 730000, China; Key Laboratory for Land Surface Process and Climate Change in Cold and Arid Regions, Chinese Academy of Sciences, Lanzhou, 730000, China; Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, United States; Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, United States
推荐引用方式 GB/T 7714	Yun H.,Wu Q.,Zhuang Q.,et al. Consumption of atmospheric methane by the Qinghai-Tibet Plateau alpine steppe ecosystem[J],2018,12(9).
APA	Yun H..,Wu Q..,Zhuang Q..,Chen A..,Yu T..,...&Liu L..(2018).Consumption of atmospheric methane by the Qinghai-Tibet Plateau alpine steppe ecosystem.Cryosphere,12(9).
MLA	Yun H.,et al."Consumption of atmospheric methane by the Qinghai-Tibet Plateau alpine steppe ecosystem".Cryosphere 12.9(2018).