A Study On The Sap Flow Of Populus Euphratica In Ejina County

Applied Thermal Dissipation Sapwood Flow Velocity Probe(TDP),the daily change of the sap flow velocity of Populus euphratica were measured systematically at different weather condition(cloudy or clear),different depth in the trunk and different directions in the trunk under the condition that tree grow natural.Through the synchronous measurement of the tree physiology indexes and the environment factors,the influence degree and response by the outside environment factors of affection the sap flow velocity were analyzed deeply,the mechanism of inside regulated and the outside influence factors of transpiration were displayed,the daily change,season change and year change of the tree biology characteristics and the main environment factors of the influential sap flow of Populus euphratica were discussed.The results showed that:the sap flow velocity of every chest tree showed low~high~low changes,the maximum sap flow velocity of 50cm and 28cm chest trees in 25mm under cambium,the maximum sap flow velocity of 15cm chest trees in 15mm under cambium;the sap flow velocity of the south and west in the trunk more higher then the east and north;the daily change and season change of the sap flow velocity associated with the Ta,RH,PRA,VPD and WS,but the main function was different under the different conditions,we can choose the best model in order to realize the instant estimation of single wood water consumption,the regression equation of the daily change sap flow respond to the environment factors of Populus euphratica in different weather condition and different season were built;we used the regression equation of sap flow with chest diameter,tree high,tree hat range and sap area to realize the caling-up of tree transpiration and water consumption through the single tree to the wood.The theories foundation were provided in order to announce to the mechanism of ecosystem using water and the continuous development of Ejina oasis in aftertime,the scientific bases were provided in order to protect and recover the oasis ecosystem system.