Characteristics Of Water Consumption Of Salix Plantations Under Different Thinning Intensity

Salix is a shrub of the Salix genus.It is one of the native tree species in the Mao Wusu Desert.It is characterized by drought tolerance,cold resistance,high temperature resistance,sand resistance,strong sprouting,easy planting,rapid growth,and high economic value.Local sand control and sand prevention,improvement of the ecological environment,and development of the advantages of the sand industry,the advantages of shrub resources.In this paper,Salix psammophila was cut and bred with different intensities.At the same time,the branches of Salix psammophila were divided into new branches(6-8mm)and mature branches(9-10mm)(>11mm),and CK1 was set(uncut).0.3M(30% of harvested branches of Salix psammophila),0.5M(50% of harvested branches of Salix psammophila),0.7M(70% of harvested branches of Salix psammophila),and CK2(Full cut).The effects of these five tending strengths on the stem flow rate of Salix psammophila with different diameters were studied.The pros and cons of each tending intensity were judged based on the change of stem flow rate,and on this basis,the sap flow of Salix psammophila was evaluated at each tending intensity.With the relationship of different meteorological factors,the evapotranspiration and soil evaporation within the Salix psammophila will be calculated based on the measured sap flow rate values and meteorological observations,so as to determine the scientific and reasonable tending intensity and provide the local Shaliushu shrub land management Scientific basis.The result of the measurement is as follows:(1).Raising favors the sprouting of new branches of Salix,and it is more obvious after high intensity tending.The sap flow rate of Salix psammophila was in the form of "?" shape.(2).With different diameters,Salix chinensis differs in its stem flow rate and responds to changes in tending intensity.The sensitivity of sap flow velocity to tending intensity decreased with the increase of the diameter of Salix psammophila.(3).The sap flow rate of Salix psammophila has a significant nonlinear relationship with solar radiation and temperature,and has a different degree of correlation with environmental factors.The order of the meteorological factors affecting the sap flow rate of salix praecox during full leaf development is: solar radiation>Atmospheric temperature> Air relative humidity> wind speed;Salix stalk flow rate is most affected by soil water content at 30 cm.(4).Under different tending intensity,total transpiration of Salix psammophila and soil evaporation in plots were different.The order of transpiration of plants under different tending intensity was: CK1>0.3M>0.5M>0.7M>CK2;soil The order of evaporation at different tending intensity was: CK2>0.7M>0.5M>0.3M>CK1,but the difference in soil evaporation values was not significant.(5).With the increase of tending intensity,the transpiration of fresh shoots of Salix psammophila gradually occupied the main position of plant water consumption.The transpiration amount of Salix psammophila treated with 0.7M was the largest,and the contribution rate of transpiration of new branches accounted for more than 51% in the growing season of the experimental period.The contribution rates of transpiration and water consumption of mature branches were both 23%~26%;in the full leaf stage,Salix is a major way of water consumption in forest lands,and soil evaporation in leaf stage and deciduous stage is the main water consumption mode during this period.Therefore,in order to achieve the balance of the water consumption of Salix psammophila and the planting number of vegetation,it is recommended to use 0.7M tending strength.