Study On The Effect Of Flat Cropping On The Physiological Ecology And Soil Moisture Content Of Caragana Korshinskii

In order to explore the changes of physiological ecology and soil moisture content of Caragana korshinskii under different stumping methods,and to reveal the significance of stumping measures on vegetation renewal and rejuvenation in ecologically fragile areas of Inner Mongolia.In this thesis,the artificial Caragana korshinskii forest in Damao Banner,Baotou City,Inner Mongolia was taken as the research object,and the non-stubble mode was used as the control.The effects of mechanical stubble and biological stubble on the physiological and ecological effects of the above-ground and underground parts of Caragana korshinskii were analyzed,and the comprehensive analysis was carried out.The main conclusions are as follows:（1）The ground index,plant height and crown width of Caragana korshinskii were lower than those of the control in a short time,but the length of new branches was higher than that of the control.The over-compensation growth of Caragana korshinskii occurred after stumping treatment.The plant height compensation index of mechanical stumping was 1.42 and that of biological stumping was 1.23.The biomass compensation index of mechanical stubble was 1.82,and that of biological stubble was 1.49.（2）Different flat cropping methods promoted the growth of fine roots of Caragana korshinskii.The total length of fine roots of Caragana korshinskii under mechanical and biological flat cropping was 976.19cm and 865.06cm,respectively,while that of non flat cropping was 799.64cm;The total volume of fine roots of Caragana korshinskii under mechanical and biological tillage was 7.61 cm³and 6.55cm³,respectively,while that of Caragana korshinskii under non tillage was 6.08 cm³;The total surface areas of fine roots of Caragana korshinskii under mechanical and biological tillage were 759.61cm²and 653.69cm²,respectively,while those under non tillage were 606.69cm².（3）The net photosynthetic rate,transpiration rate,and water use efficiency of Caragana korshinskii increased significantly after the flat stubble treatment,while the stomatal limit value of Caragana korshinskii decreased;The diurnal mean of net photosynthetic rate of Caragana korshinskii under different flat cropping patterns was as follows:mechanical flat cropping(7.91μmol·m^-2s^-1)>biological flat cropping(6.21μmol·m^-2s^-1)>non flat cropping(5.53μmol·m^-2s^-1);The specific performance of net photosynthetic rate,transpiration rate,stomatal conductance,and water use efficiency of Caragana korshinskii in different months under different flat cropping methods is August>July>September>June>May,while the stomatal limit value is September>August>July>June>May.（4）The fine root vigor of Caragana korshinskii increased first and then decreased with the increase of month and soil layer,reaching the maximum value in August and 10～20 cm soil layer,and the minimum value in June.The fine root vigor of Caragana korshinskii under mechanical,biological,and non flat cropping in August was 1.67,1.67,and 1.64 times higher than that in June,respectively;The proline content and soluble sugar content in the fine roots of Caragana korshinskii showed a trend of first decreasing and then increasing with the increase of months,with the maximum value in June.The proline content in the fine roots of Caragana korshinskii under various flat cropping methods was 24.24%for mechanical flat cropping,respectivelyμg/g FW,biological flat stubble 26.57μg/g FW and non flat stubble mode 37.44μg/g FW,soluble sugar content was 86.11mg/g FW for mechanical tillage,78.82mg/g FW for biological tillage,and 64.58mg/g FW for non tillage;With the increase of soil depth,it first decreases and then increases,reaching the lowest value at 10～20 cm.（5）The spatial distribution characteristics of soil moisture under Caragana korshinskii forest were as follows:in the horizontal direction,the soil moisture content decreased gradually with the increase of distance from the foundation of the standard cluster,and in the vertical direction,the soil moisture content decreased gradually with the increase of soil depth.The variation range of soil moisture content under Caragana korshinskii forest with different cutting methods was 4.04%～5.28%for mechanical cutting,3.84%～4.78%for biological cutting and 3.57%～4.52%for non-cutting mode.（6）The membership function of each index of Caragana korshinskii under different stumping methods was comprehensively analyzed.The results showed that the two stumping methods were significantly better than the non-stumping mode.The mechanical stumping had the best performance,followed by the biological stumping effect.The specific performance was mechanical stumping（0.44）>biological stumping（grazing）（0.43）>non-stumping mode（0.40）.