Impact of typical forest types on soil erosion in water source area of Kunming

In order to clarify the effects of different forest types on the resistance to soil erosion in important water source areas of Kunming, taking small watershed soils under three different forests as the research objects, through field simulation and lab analysis methods, analyzed three different soils' erosion resistances. The results showed that the soil shear strength values of three typical plots were significantly different, and followed the order of Pinus yunnanensis landconifer land Eucalyptus woodland. Soil erosion coefficients of three different forests were not significant, as soil resistance index of conifer land was biggest(39%), followed by Eucalyptus woodland(37%) and Yunnan pine(24%). In conditions of big and long duration rainfall, the effect of soil in Eucalyptus × Yunnan pine mixed forest on resisting disintegrating was more significant. Using principal component analysis to analyze these three forest soils' resistance to erosion characteristics,the comprehensive evaluation model was obtained: Y=0.763Y1+0.236Y2. And then the order of resistance to erosion of three forest soils was gained, which showed conifer ground(0.150) Eucalyptus woodland(0.127) Yunnan pine land(-0.079),so the effect of mixed forests on preventing water loss and soil erosion was better than that of pure forests.