Research On The Ability Of Soil And Water Conservation Of Different Plant Community In Fuyuan County

Four widely distributed plant communities of Pinus yunnanensis forest, Pinus armandii forest, Alnus nepalensis forest and mixed forest were selected to study through the methods of site investigation and typical sample in Fuyuan County. Comparing with Wasteland, analyzed these factors of community biomass, forest interception, soil permeability, water storage of soil, soil fertility coefficient and community Carbon-sink function, then used the method of cluster analysis to evaluate soil and water conservation capacity of the different communities. It provided reference for vegetation recovery for Fuyuan County. The results were as follows:1. Structure of community stand was divided into arbor layer, understory layer and litter layer for researching the community biomass, also, regression of biomass model was used. The results showed that the arbor layer's biomass was highest, and different communities biomass had significant difference as follows of Mixed forest>Pinus armandii forest>Alnus nepalensis forest>Pinus yunnanensis forest>Wasteland, the highest was 78.054 t.hm-2, and the lowest was 1.810 t.hm-2.2. The method of dip in water was used to analyze the forest stand interception, The litter layer's interception was highest, and different communities interception had significant difference as follows of Mixed forest>P inus armandii foest>Alnus nepalensis forest>Pinus yunnanensis forest>Wasteland, the highest was 3.374 mm, and the lowest was 0.062 mm.3. The method of gray correlation was used to analyze the soil fertility, and follow the order of Mixed forest>Pinus armandii forest>Pinus yunnanensis forest>Alnus nepalensis forest> Wasteland. It shows that reforesting in wasteland had been proved improving to soil physicochemical property.4. Using the method of cutting ring to analyze soil infiltration of different community, the results showed that the trend of soil infiltration went down gradually and stable with the time. The initial and stable rate followed the order of Pinus armandii forest>Mixed forest>Alnus nepalensis forest>Pinus yunnanensis forest>Wasteland, the highest of initial rate was 18.264mm.min-1, and the lowest was 8.387 mm.min-1, but the highest of stable rate was 3.494 mm.min-1, and the lowest was 0.910 mm.min-1.5. Using the method of regular observations to monitor natural soil moisture dynamically, the results showed that the natural soil moisture had changed great at different time, the highest was 28.76%, and the lowest was 4.68%, and the trend of natural soil moisture was stable with the soil layer's increase. Combined with soil bulk density to analyze the water storage of soil, as follows of Mixed forest>Alnus nepalensis forest>Pinus armandii forest>Pinus yunnanensis forest> Wasteland, the highest was 1.96mm, and the lowest was 0.89mm.6. The unit of carbon storage of community between 64.473 t.hm-2 to 148.982 t.hm-2 and followed the order of Mixed forest>Pinus yunnanensis forest>Pinus armandii forest>Alnus nepalensis forest>Wasteland by the carbon density of arbor layer, understory layer, litter layer and soil. It showed that reforesting in wasteland had been proved improving to community Carbon-sink function.7. Using the method of fixed point to analyze the community runoff and soil erosion, the results showed that the runoff was between 2.083mm to 62.301mm, followed the order of Wasteland>Pinus yunnanensis forest>Alnus nepalensis forest>Pinus armandii forest>Mixed forest, and the soil erosion was between 0.065t. hm-2 to 4.414t. hm-2, followed the order of Wasteland>Alnus nepalensis forest>Pinus yunnanensis forest>Pinus armandii forest>Mixed forest.8. The soil and water conservation followed the order of Pinus armandii forest>Mixed forest>Pinus yunnanensis forest>Alnus nepalensis forest> Wasteland by using the method of cluster analysis to evaluate community biomass, forest interception, soil permeability, water storage of soil, soil fertility coefficient and community Carbon-sink function.