气候变化领域集成服务门户(CCPortal): Quantifying the Controls on Evapotranspiration Partitioning in the Highest Alpine Meadow Ecosystem

CCPortal

DOI	10.1029/2019WR024815
	Quantifying the Controls on Evapotranspiration Partitioning in the Highest Alpine Meadow Ecosystem
	Cui, Jiangpeng; Tian, Lide; Wei, Zhongwang; Huntingford, Chris; Wang, Pei; Cai, Zhongyin; Ma, Ning; Wang, Lixin
通讯作者	Cui, JP (通讯作者)
发表日期	2020
ISSN	0043-1397
EISSN	1944-7973
卷号	56 期号:4
英文摘要	Quantifying the transpiration fraction of evapotranspiration (T/ET) is crucial for understanding plant functionality in ecosystem water cycles, land-atmosphere interactions, and the global water budget. However, the controls and mechanisms underlying the temporal change of T/ET remain poorly understood in arid and semiarid areas, especially for remote regions with sparse observations such as the Tibetan Plateau (TP). In this study, we used combined high-frequency laser spectroscopy and chamber methods to constrain estimates of T/ET for an alpine meadow ecosystem in the central TP. The three isotopic end members in ET (delta (ET)), soil evaporation (delta (E)), and plant transpiration (delta (T)) were directly determined by three newly customized chambers. Results showed that the seasonal variations of delta (ET), delta (E), and delta (T) were strongly affected by the precipitation isotope (R-2 = 0.53). The delta O-18-based T/ET agreed with that of delta H-2. Isotope-based T/ET ranged from 0.15 to 0.73 during the periods of observation, with an average of 0.43. This mean result was supported by T/ET derived from a two-source model and eddy covariance observations. Our overarching finding is that at the seasonal timescale, surface soil water content (theta) dominated the change of T/ET, with leaf area index playing only a secondary role. Our study confirms the critical impact of soil water on the temporal change of T/ET in water-limited regions such as the TP. This knowledge sheds light on diverse land-surface processes, global hydrological cycles, and their modeling. Key Points Laser spectroscopy and the chamber method were used to estimate T/ET in the central Tibetan Plateau Near-surface soil water content dominated the temporal change of T/ET, with leaf area index playing a secondary role Our study highlights the critical impact of environmental conditions on the temporal change of T/ET in water-limited regions
关键词	STABLE-ISOTOPE PROFILES WATER-VAPOR STATE TRANSPIRATION VEGETATION CONTROL SOIL EVAPORATION LEAF WATER FLUXES DELTA-O-18 OXYGEN MODEL
英文关键词	chamber; evapotranspiration partitioning; leaf area index; soil water content; stable isotopes; Tibetan Plateau
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Marine & Freshwater Biology ; Water Resources
WOS类目	Environmental Sciences ; Limnology ; Water Resources
WOS记录号	WOS:000538987800024
来源期刊	WATER RESOURCES RESEARCH
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/260089
推荐引用方式 GB/T 7714	Cui, Jiangpeng,Tian, Lide,Wei, Zhongwang,et al. Quantifying the Controls on Evapotranspiration Partitioning in the Highest Alpine Meadow Ecosystem[J]. 中国科学院青藏高原研究所,2020,56(4).
APA	Cui, Jiangpeng.,Tian, Lide.,Wei, Zhongwang.,Huntingford, Chris.,Wang, Pei.,...&Wang, Lixin.(2020).Quantifying the Controls on Evapotranspiration Partitioning in the Highest Alpine Meadow Ecosystem.WATER RESOURCES RESEARCH,56(4).
MLA	Cui, Jiangpeng,et al."Quantifying the Controls on Evapotranspiration Partitioning in the Highest Alpine Meadow Ecosystem".WATER RESOURCES RESEARCH 56.4(2020).