The Impact Of Central Yunnan The Metapelites Area Of ​​vegetation Changes On Soil Erosion Research

The theories and methods of soil and water conservation,ecology,water conservancy engineering,forestry and hydrology are applied to research the change of vegetation in mudstone center area of Yunnan Province in this paper.Weir for arrangement of limnimeter,rainfall of limnimeter and limnimeter are set to observe surface runoff.The amount of soil erosion is calculated by sampling,drying and weighing.The different vegetation types,sepecies richness and projection coverage of woody and herb layers are investigated.The result shows that the influence on soil and water losses is different when the vegetation types,projection coverage and species richness are difference.Soil and water losses with change of vegetation in mudstone center area of Yunnan Province are as follows:1.By two-year observation,when the rainfall is same,the result of researching the influence on soil and water losses shows the surface runoff of vegetation types is different.P.Yunnanensis pine needle-leaved and bread-leaved forest(1000～1400m~3/hm~2.a),P.Yunnanensis pine needle-leaved forest(1350～1800m~3/hm~2.a), shrub and herb community(degraded ecosystem)(3500～4500m~3/hm~2.a).The runoff rate of different vegetation types is different also.P.Yunnanensis pine needle-leaved and bread-leaved forest(0.12～0.13),P.Yunnanensis pine needle-leaved forest (0.17～0.17),shrub and herb community(degraded ecosystem)(0.39～0.45).The P.Yunnanensis needle-leaved and bread-leaved forest's surface runoff is the best, P.Yunnanensis pine needle-leaved forest takes the second place,The shrub and herb community intecting the surface runoff's influence to surface runoff is the least.The amount of soil erosion is different with vegetation types's difference.P.Yunnanensis pine needle-leaved and bread-leaved forest(110～300t/km~2.a),P.Yunnanensis pine needle-leaved forest(440～710t/km~2.a),shrub and herb community(3200～3800t/km~2.a).In three vegetation types,the shrub and herb's capability to cotroling soil erosion is the leasttheir soil erosion is much more than other two vegetation types.2.The influence on surface runoff and soil erosion with vegetation types's difference is provided with corporate quality.With the precipitation's increasing,the surface runoff and amount of soil erosion of three different vegetations are also increased,but the shrub and herb community sincreasing's increasing amount is the most.P.Yunnanensis pine needle-leaved forest takes the second place.The P.Yunnanensis needle-leaved and bread-leaved forest is the least.3.The species richness is provided with the influence on soil and water losses. The surface runoff of P.Yunnanensis needle-leaved and bread-leaved forest has the most species richness(1000～1400ma/hm~2.a).P.Yunnanensis pine needle-leaved forest has the least species richness(1350～1800m~3/hm~2.a).Shrub and herb community is placed in the middle(degraded ecosystem)(3500～4500m~3/hm~2.a).Soil erosion's amount of the P.Yunnanensis pine needle-leaved and bread-leaved forest with the most species richness(110～300t/km~2.a).P.Yunnanensis pine needle-leaved forest with the least species richness(440～710t/km~2.a),shrub and herb community is placed in the middle(3200～3800t/km~2.a).The result show during the course of vegetation succession,the resumptive species community for example P.Yunnanensis pine needle-leaved forest and P.Yunnanensis pine needle-leaved and bread-leaved forest is better than the non-resumptive one,the capability to control surface runoff is better than the non-resumptive shrub and herb community.To the resumptive species community with the better richness,it's capability to control soil and water losses better.4.The vegetation projection coverage is providing with the influence on soil and water losses.The surface runoff of P.Yunnanensis pine needle-leaved and bread-leaved with the most forest projection coverage(1000～1400m~3/hm~2.a)and the forest projection coverage of P.Yunnanensis pine needle-leaved is placed in the middle (1350～1800m~3/hm~2.a)and the shrub and herb with the least community projection coverage(3500～4500m~3/hm~2.a).The soil erosion amount of P.Yunnanensis pine needle-leaved and bread-leaved with the most forest~/s projection coverage(110～300t/km~2.a)and P.Yunnanensis pine needle-leaved forest projection coverage is placed in the middle(440～710t/km~2.a)and shrub and herb with the least community forest projection coverage(3200～3800t/km~2.a).The influence studying of the vegetation projection coverage on the soil and water losses manifests that the surface runoff and the soil erosion are decreased with the increasing of the vegetation projection coverage.