Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem

doi:10.1016/j.agrformet.2020.108254

	Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem
	Sun, Shaobo 6,7; Che, Tao 2; Gentine, Pierre 3,4; Chen, Qiting 1; Wang, Lichun 6,7; Yan, Zhifeng 6,7; Chen, Baozhang 5; Song, Zhaoliang 6,7
刊名	AGRICULTURAL AND FOREST METEOROLOGY
	2021-02-15
卷号	297 页码:11
关键词	alpine meadow water table level frozen soil carbon exchange soil respiration Tibetan Plateau
ISSN号	0168-1923
DOI	10.1016/j.agrformet.2020.108254
通讯作者	Sun, Shaobo(shaobo.sun@tju.edu.cn) ; Song, Zhaoliang(zhaoliang.song@tju.edu.cn)
英文摘要	Wet alpine meadows generally act as a significant carbon sink, since their low rate of soil decomposition determines a much smaller ecosystem respiration (Re) than photosynthesis. However, it remains unclear whether the low soil decomposition rate is determined by low temperatures or by nearly-saturated soil moisture. We explored this issue by using five years of measurements from two eddy-covariance sites with low temperature and significantly different soil water conditions. The results showed that both sites were carbon sinks. However, despite a smaller annual gross primary productivity, the wet site with a shallow groundwater showed a much higher carbon use efficiency and larger carbon sink than the dry site (which had a deeper water table) due to its much lower Re. Our analyses showed that Re of the wet site was significantly decreased under the nearly-saturated soil condition during the unfrozen seasons. This effect of nearly-saturated soil water on Re increased with soil depths. In contrast, at the dry site the high soil water content favored Re. The corresponding soil temperature at both sites expectedly showed large and positive effects on Re. These results demonstrated that the high carbon sink of the wet alpine meadow was mainly caused by the inhibiting effects of the nearly-saturated soil condition on soil respiration rather than by the low temperatures. Therefore, we argue that a warming-induced shrinking cryosphere may affect the carbon dynamics of wet and cold ecosystems through changes in soil hydrology and its impact on soil respiration. In addition, our study highlights the different responses of soil respiration to warming across soil depths. The thawing of frozen soil may cause larger CO2 emission in the top soil, while it may also partially contribute to slowing down soil carbon decomposition in the deep soil through decreasing metabolic activity of aerobic organisms.
资助项目	National Key R&D Program of China[2017YFC0503904] ; National Key R&D Program of China[2018YFA0606001] ; National Natural Science Foundation of China[41801061] ; Peiyang Young Scholar Program[2020XRG-0066] ; NASA[NNH17ZDA0OIN-THP]
WOS关键词	HEIHE RIVER-BASIN ; CLIMATE-CHANGE ; TIBETAN PLATEAU ; DIOXIDE EXCHANGE ; EDDY-COVARIANCE ; CO2 EXCHANGE ; HETEROTROPHIC RESPIRATION ; INTERANNUAL VARIABILITY ; METHANE FLUXES ; WATER
WOS研究方向	Agriculture ; Forestry ; Meteorology & Atmospheric Sciences
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000608676000020
资助机构	National Key R&D Program of China ; National Natural Science Foundation of China ; Peiyang Young Scholar Program ; NASA
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/136386]
专题	中国科学院地理科学与资源研究所
通讯作者	Sun, Shaobo; Song, Zhaoliang
作者单位	1.Chinese Acad Sci, Aerosp Informat Res Inst, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China 2.Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Heihe Remote Sensing Expt Res Stn, Lanzhou 730000, Peoples R China 3.Columbia Univ, Earth Inst, New York, NY 10027 USA 4.Columbia Univ, Dept Earth & Environm Engn, New York, NY 10027 USA 5.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, State Key Lab Resources & Environm Informat Syst, Beijing 100101, Peoples R China 6.Tianjin Univ, Sch Earth Syst Sci, Inst Surface Earth Syst Sci, Tianjin 300072, Peoples R China 7.Tianjin Univ, Tianjin Key Lab Earth Crit Zone Sci & Sustainable, Tianjin 300072, Peoples R China
推荐引用方式 GB/T 7714	Sun, Shaobo,Che, Tao,Gentine, Pierre,et al. Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem[J]. AGRICULTURAL AND FOREST METEOROLOGY,2021,297:11.
APA	Sun, Shaobo.,Che, Tao.,Gentine, Pierre.,Chen, Qiting.,Wang, Lichun.,...&Song, Zhaoliang.(2021).Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem.AGRICULTURAL AND FOREST METEOROLOGY,297,11.
MLA	Sun, Shaobo,et al."Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem".AGRICULTURAL AND FOREST METEOROLOGY 297(2021):11.