气候变化领域集成服务门户(CCPortal): Depressed hydraulic redistribution of roots more by stem refilling than by nocturnal transpiration for Populus euphratica Oliv. in situ measurement

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DOI	10.1002/ece3.3875
	Depressed hydraulic redistribution of roots more by stem refilling than by nocturnal transpiration for Populus euphratica Oliv. in situ measurement
	Yu, Tengfei; Feng, Qi; Si, Jianhua; Mitchell, Patrick J.; Forster, Michael A.; Zhang, Xiaoyou; Zhao, Chunyan
发表日期	2018
ISSN	2045-7758
卷号	8 期号:5
英文摘要	During the night, plant water loss can occur either through the roots, as hydraulic redistribution (HR), or through the leaves via the stoma, as nocturnal transpiration (E-n), which was methodologically difficult to separate from stem refilling (R-e). While HR and E-n have been reported across a range of species, ecosystem, and climate zone, there is little understanding on the interactions between E-n and/or R-e and HR. As water movement at night occurs via gradients of water potential, it is expected that during periods of high atmospheric vapor pressure deficit (VPD), water loss via E-n will override water loss via HR. To test this hypothesis, sap flow in stems and roots of Populus euphratica Oliv. trees, growing in a riparian zone in a hyperarid climate, was measured once in a year. Nocturnal stem sap flow was separated into E-n and R-e using the forecasted refilling method. Substantial nocturnal sap flow (38% of 24-hr flux on average) was observed and positively correlated with VPD; however, the strength of the correlation was lower (R-2=.55) than diurnal sap flow (E-d) (R-2=.72), suggesting that nocturnal stem sap flow was attributed to both water loss through the canopy and replenishment of water in stem tissues. Partitioning of nocturnal sap flow shows that R-e constituted approximately 80%, and E-n similar to 20%, of nocturnal sap flow. The amount of root sap flow attributed to redistribution was negatively related to E-d (R-2=.69) and the amount of acropetally sap flow in stems, R-e (R-2=.41) and E-n (R-2=.14). It was suggested that the magnitude of HR is more strongly depressed by R-e that was recharge to the water loss via E-d than by E-n. It was consistent with whole-tree water balance theory, that the nighttime upward sap flow to xylem, stem refilling and transpiration, may depress hydraulic redistribution of roots.
关键词	desert riparian trees hydraulic redistribution nocturnal transpiration sap flow stem refilling
学科领域	Environmental Sciences & Ecology; Evolutionary Biology
语种	英语
WOS研究方向	Ecology ; Evolutionary Biology
来源期刊	ECOLOGY AND EVOLUTION
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/112003
作者单位	Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Alxa Desert Ecohydrol Expt Res Stn, Lanzhou, Gansu, Peoples R China
推荐引用方式 GB/T 7714	Yu, Tengfei,Feng, Qi,Si, Jianhua,et al. Depressed hydraulic redistribution of roots more by stem refilling than by nocturnal transpiration for Populus euphratica Oliv. in situ measurement[J]. 中国科学院西北生态环境资源研究院,2018,8(5).
APA	Yu, Tengfei.,Feng, Qi.,Si, Jianhua.,Mitchell, Patrick J..,Forster, Michael A..,...&Zhao, Chunyan.(2018).Depressed hydraulic redistribution of roots more by stem refilling than by nocturnal transpiration for Populus euphratica Oliv. in situ measurement.ECOLOGY AND EVOLUTION,8(5).
MLA	Yu, Tengfei,et al."Depressed hydraulic redistribution of roots more by stem refilling than by nocturnal transpiration for Populus euphratica Oliv. in situ measurement".ECOLOGY AND EVOLUTION 8.5(2018).