干旱区生态环境知识资源中心(Arid): Environmental Control on Transpiration: A Case Study of a Desert Ecosystem in Northwest China

Arid

DOI	10.3390/w12041211
	Environmental Control on Transpiration: A Case Study of a Desert Ecosystem in Northwest China
	Xu, Shiqin 1,2; Yu, Zhongbo 1,2
通讯作者	Yu, Zhongbo
来源期刊	WATER
EISSN	2073-4441
出版年	2020
卷号	12 期号:4
英文摘要	Arid and semi-arid ecosystems represent a crucial but poorly understood component of the global water cycle. Taking a desert ecosystem as a case study, we measured sap flow in three dominant shrub species and concurrent environmental variables over two mean growing seasons. Commercially available gauges (Flow32 meters) based on the constant power stem heat balance (SHB) method were used. Stem-level sap flow rates were scaled up to stand level to estimate stand transpiration using the species -specific frequency distribution of stem diameter. We found that variations in stand transpiration were closely related to changes in solar radiation (Re), air temperature (T), and vapor pressure deficit (VPD) at the hourly scale. Three factors together explained 84% and 77% variations in hourly stand transpiration in 2014 and 2015, respectively, with Rs being the primary driving force. We observed a threshold control of VPD (similar to 2 kPa) on stand transpiration in two-year study periods, suggesting a strong stomatal regulation of transpiration under high evaporative demand conditions. Clockwise hysteresis loops between diurnal transpiration and T and VPD were observed and exhibited seasonal variations. Both the time lags and refill and release of stem water storage from nocturnal sap flow were possible causes for the hysteresis. These findings improve the understanding of environmental control on water flux of the arid and semi-arid ecosystems and have important implications for diurnal hydrology modelling.
英文关键词	sap flow water-limited ecosystem transpiration hysteresis nocturnal sap flow
类型	Article
语种	英语
国家	Peoples R China
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:000539527500288
WOS关键词	INLAND RIVER-BASIN ; SAP-FLOW ; CANOPY CONDUCTANCE ; WATER-USE ; NIGHTTIME TRANSPIRATION ; STOMATAL CONDUCTANCE ; NORWAY SPRUCE ; STORED WATER ; RAIN-FOREST ; RESPONSES
WOS类目	Environmental Sciences ; Water Resources
WOS研究方向	Environmental Sciences & Ecology ; Water Resources
来源机构	河海大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/318941
作者单位	1.Hohai Univ, State Key Lab Hydrol Water Resources & Hydraul En, Nanjing 210098, Peoples R China; 2.Hohai Univ, Coll Hydrol & Water Resources, Nanjing 210098, Peoples R China
推荐引用方式 GB/T 7714	Xu, Shiqin,Yu, Zhongbo. Environmental Control on Transpiration: A Case Study of a Desert Ecosystem in Northwest China[J]. 河海大学,2020,12(4).
APA	Xu, Shiqin,&Yu, Zhongbo.(2020).Environmental Control on Transpiration: A Case Study of a Desert Ecosystem in Northwest China.WATER,12(4).
MLA	Xu, Shiqin,et al."Environmental Control on Transpiration: A Case Study of a Desert Ecosystem in Northwest China".WATER 12.4(2020).