Divergent environmental responses of long-term variations in evapotranspiration over four grassland ecosystems in China based on eddy-covariance measurements

NWIPB OpenIR

	Divergent environmental responses of long-term variations in evapotranspiration over four grassland ecosystems in China based on eddy-covariance measurements
	Zheng, Han; Yu, Guirui; Wang, Qiufeng; Chen, Zhi; Zhu, Xianjin; Bao, Han; Sun, Yuchen; Niu, Panpan; Li, Yingnian; Shi, Peili; Hao, Yanbin; Zhang, Fawei; Niu, Zhongen
	2023
发表期刊	JOURNAL OF HYDROLOGY
卷号	625
摘要	Understanding the long-term variation in evapotranspiration (ET) for the spatially distributed grasslands is crucial for the accurate prediction of ET response to climate change. In this study, we analyzed the interannual variability (IAV) of ET and its responses to environmental conditions at four grassland ecosystems across a wide range of climatic and biome conditions based on the long-term (9-11 years) eddy-covariance measurements. The four ecosystems encompassed the most prevalent grassland vegetations in China, containing a typical temperate steppe, an alpine meadow-steppe, an alpine shrubland meadow, and an alpine marsh meadow. The IAVs of annual ET at the typical temperate steppe and the alpine meadow-steppe were primarily affected by either change in precipitation (P) or relative humidity (RH). Leaf area index (LAI) was the dominant factor controlling the IAVs of annual and growing-season ET at the alpine shrubland meadow, and the IAV of LAI was significantly correlated with P variation. As to the alpine marsh meadow, net radiation turned to be the dominant factor for the IAV of annual ET, additionally with significant effects from water supply condition (P and RH) on the IAV of growing-season ET. Similar environmental responses were also found for the IAVs of mean surface conductance (g(s)) across the sites. Specifically, annual and growing-season mean gs significantly increased with increases in LAI at the alpine shrubland meadow, and appeared to be more sensitive to changes in water availability and VPD at the typical temperate steppe and the alpine meadow-steppe. Significant linear relationships were also observed among the IAVs of mean Priestley-Taylor coefficient (alpha = ET/ETeq, where ETeq is the equilibrium evaporation), decoupling coefficient (Omega), and g(s) on both the annual and growing-season basis in this study. Moreover, the variabilities of annual mean g(s), Omega, and alpha further demonstrated the energy-limited conditions at the alpine marsh meadow, and the overall water-limited conditions at the other three grasslands. This study reveals the divergent environmental responses of long-term ET variations over grassland ecosystems, and contributes to the comprehensive understanding on the ET process and modeling efforts as well.
收录类别	SCIE
文献类型	期刊论文
条目标识符	http://210.75.249.4/handle/363003/61591
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	Zheng, Han,Yu, Guirui,Wang, Qiufeng,et al. Divergent environmental responses of long-term variations in evapotranspiration over four grassland ecosystems in China based on eddy-covariance measurements[J]. JOURNAL OF HYDROLOGY,2023,625.
APA	Zheng, Han.,Yu, Guirui.,Wang, Qiufeng.,Chen, Zhi.,Zhu, Xianjin.,...&Niu, Zhongen.(2023).Divergent environmental responses of long-term variations in evapotranspiration over four grassland ecosystems in China based on eddy-covariance measurements.JOURNAL OF HYDROLOGY,625.
MLA	Zheng, Han,et al."Divergent environmental responses of long-term variations in evapotranspiration over four grassland ecosystems in China based on eddy-covariance measurements".JOURNAL OF HYDROLOGY 625(2023).