Drought occurrence and time-dominated variations in water use efficiency in an alpine meadow on the Tibetan Plateau

doi:10.1002/eco.2360

	Drought occurrence and time-dominated variations in water use efficiency in an alpine meadow on the Tibetan Plateau
	Zhao, Tingting 4; Zhang, Yangjian 1,2,3; Zhang, Tao 4; Xu, Mingjie 4; Zhu, Juntao 2,3; He, Yongtao 1,2; Yu, Guirui 1,2
刊名	ECOHYDROLOGY
	2021-10-03
页码	15
关键词	carbon and water cycles drought eddy covariance evapotranspiration grassland gross ecosystem productivity Tibet water use efficiency
ISSN号	1936-0584
DOI	10.1002/eco.2360
通讯作者	Zhang, Tao(zhangt@syau.edu.cn) ; Xu, Mingjie(xumj@syau.edu.cn)
英文摘要	Under global climate change, more frequent and widespread droughts have dramatic impacts on the water and carbon cycles. Water use efficiency (WUE) is a commonly used indicator reflecting the trade-off relationship between carbon sequestration and water consumption. Therefore, this study aims to clarify the variations in WUE and the effects of drought on WUE in sensitive alpine meadows on the Tibetan Plateau. Based on 6-year (2013-2018) continuous carbon and water flux data observed by the eddy covariance system, WUE was calculated by gross ecosystem productivity (GEP)/evapotranspiration (ET). WUE followed a unimodal variation with time during growing seasons in the years without droughts. However, drought disrupted this pattern by its effects on the coupled relationship between carbon and water fluxes. Specifically, droughts showed divergent effects on WUE variations in different periods of the growing seasons. In the early-growing seasons, droughts induced an increase in WUE. During this period, WUE was mainly regulated by temperature and leaf area index (LAI), and the GEP was low due to the smaller LAI. Therefore, the drought-induced reduction in GEP was less than that in ET; thus, WUE increased. In the mid-growing seasons, droughts depressed WUE. WUE was dominated by water conditions and the LAI during this period. When drought occurred, GEP decreased faster than ET, and hence, WUE decreased. In the late-growing season, WUE was mainly driven by temperature and the LAI, but short-term drought slightly enhanced WUE. These results are helpful in understanding the responses of fragile alpine ecosystems to future climate change.
资助项目	National Natural Science Foundation of China[41725003] ; National Natural Science Foundation of China[31600362] ; National Natural Science Foundation of China[42175141] ; National Natural Science Foundation of China[32061143037] ; National Key R&D Program of China[2017YFA0604801] ; China Postdoctoral Science Foundation[2018M631819] ; China Postdoctoral Science Foundation[2021M692230]
WOS关键词	NET ECOSYSTEM EXCHANGE ; CARBON SEQUESTRATION ; PRIMARY PRODUCTIVITY ; GRASSLAND ECOSYSTEMS ; SEMIARID SHRUBLAND ; CLIMATE-CHANGE ; CO2 EXCHANGE ; FOREST ; VEGETATION ; PRECIPITATION
WOS研究方向	Environmental Sciences & Ecology ; Water Resources
语种	英语
出版者	WILEY
WOS记录号	WOS:000703076300001
资助机构	National Natural Science Foundation of China ; National Key R&D Program of China ; China Postdoctoral Science Foundation
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/166083]
专题	中国科学院地理科学与资源研究所
通讯作者	Zhang, Tao; Xu, Mingjie
作者单位	1.Univ Chinese Acad Sci, Coll Resources & Environm, Beijing, Peoples R China 2.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing, Peoples R China 3.Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Beijing, Peoples R China 4.Shenyang Agr Univ, Coll Agron, Shenyang, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Tingting,Zhang, Yangjian,Zhang, Tao,et al. Drought occurrence and time-dominated variations in water use efficiency in an alpine meadow on the Tibetan Plateau[J]. ECOHYDROLOGY,2021:15.
APA	Zhao, Tingting.,Zhang, Yangjian.,Zhang, Tao.,Xu, Mingjie.,Zhu, Juntao.,...&Yu, Guirui.(2021).Drought occurrence and time-dominated variations in water use efficiency in an alpine meadow on the Tibetan Plateau.ECOHYDROLOGY,15.
MLA	Zhao, Tingting,et al."Drought occurrence and time-dominated variations in water use efficiency in an alpine meadow on the Tibetan Plateau".ECOHYDROLOGY (2021):15.