Stem sap flow variation of Tamarix ramosissima in oasis-desert ecotone and its response to environmental factors
The shelterbelt forest between oases and desert plays a vital role in preventing aeolian disasters and desertification in arid regions.Tamarix ramosissima(T.ramosissima),a typical perennial and native xerophyte shrub in Northwest China,grows naturally and is widely used in constructing artificial shelterbelt forests.The balance between water consumption and the availability of water determines the survival and growth of T.ramosissima.And global climate change will further increase the pressure on water resources in this region.In this paper,the stem sap flow(SSF)gauges,working based on the energy balance method,were used to measure sap flow,and the environmental factors were monitored simultaneously.The result showed that the cumulative SSF of T.ramosissima was 75.43kg,and the average daily SSF was 523.8g·d-1,indicating the prominent seasonal characteristics.The daily SSF of T.ramosissima was positively correlated with air temperature,photosynthetically active radiation,and the vapor pressure deficit(P＜0.001).We found that there was no significant relationship between,daily SSF and soil moisture in shallow(0-40cm)and middle(40-160cm)soil layers.T.ramosissima adapts to severe water stress through the time lag between sap flow and meteorological factors.Deep soil water and groundwater play an extremely important role in the ecological restoration and reconstruction in this extremely water-limited environment.The result of this study offers valuable insight into revealing the adaptation mechanism of T.ramosissima to drought stress and for the selection and management of afforestation species during the process of ecological restoration and reconstruction in arid regions.
Tamarix ramosissimastem sap flowmeteorological factorssoil moisturearid region
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NSTL
万方数据
