The Coupling Of Water Source And Consumption Based On The Hydrogen And Oxygen Stable Isotope Of Natural Salix Gordejevii In Otinday Sandland

With global climate change and the rapid development of economic, ecological environment is deteriorating, the contradiction between ecological and industrial water gradually increased, especially in arid and semi-arid area. Natural plant plays an extremely important role to restore productivity of desert land and maintain the ecological balance. Natural shrub is an excellent sand-fixation trees widely distributed in Otinday Sandland. In order to explore the survival situation of natural shrub in the limited water resource environment, it is necessary to research the relationship between the water use source,form and demand of shrub in different seasons. The article based on the hydrogen and oxygen isotope tracer method and put the Salix gordejevil as the target to analyze the regulation of plant-soil water movement. Meanwhile, combined with Salix gordejevil transpiration in the growth period to research relationship between water source and consumption. The main results are:(1)Using the principle of hydrogen and oxygen isotope tracer to research the water variation characteristics and the distribution law of the potential water source which is providing water to plants such as precipitation, soil water and groundwater and so on in different seasons. It shows that under the influence of the factors,such as temperature and humidity, the hydrogen and oxygen stable isotopic of potential water source exist seasonal change.The slope of atmospheric precipitation equation less than the slope of global atmospheric precipitation equation,the expression is δD=7.44δ18O+2.11,R2 is 0.93.(2)Based on the principle of hydrogen and oxygen stable isotope tracer analysis of the D,18O that contained in the plant stem water and pontential water source, to judge qualitatively the main water horizon of Salix gordejevii root. According to the principle of energy balance to set up the multi-source linear mixed model calculate quantitatively various potential water use ratio. Considered the effect of factors combined with different season temperature precipitation, groundwater depth in plants water absorption, study on the Salix gordejevii drought-resistant mechanism. The results shows Salix gordejevii can through own to adjust the direction of the optimal to achieve maximum water use.(3) According to the local meteorological data and the measured data of Salix gordejevii physiological and ecological characteristics, using the dual crop coefficient menthod introduced by FAO to calculate the water demend ET0 in research area, confirm the crop coefficient Kc of Salix gordejevii during the growth period, so that to calculate the water consumption of natural salix gordejevii is 296.67mm, and compared with the measured water consumption to prove the model, the correlation coefficient is 0.92, it shows a significant correlation.(4) Coupled with water source and consumption of Salix gordejevii in the growth period, through the analysis of the relationship between the water consumption of Salix gordejevii and the precipitation,soil water in different seasons, it suggests that soil water as the main water source for the plant when the precipitation appear deficit. At the same time quantitative analyze the contribution amount of water source of Salix gordejevii evaporation, it reflects Salix gordejevii has a good drought resistance mechanism to response to different season.