| Soil erosion has become today's most serious environmental problems, it is led to the decrease of the soil nutrient loss and productivity, the main reason of the and direct impact on the local ecological security. Central Sichuan Hilly Area is located in the Yangtze river shelter-forest siltstones. planting a large area of pure forest of Cupressus funebris Endl in the Yangtze River shelterbelt construction a project, because of a single tree species composition, planting density is too large and poor management of late and other reasons, resulting in the existing woodland, mostly low-yielding inefficient forest, water and soil conservation severe recession. Coupled with the soil in the hilly region mainly Mesozoic purple sand (page) rock weathering of soil, poor corrosion resistance, surface exposed, water loss and soil erosion situation is more serious. Therefore, the research group in 2012 to inefficient Cupressus funebris Endl forest, build tending thinning 50%(model ?), the gaps 200 square meters (natural state) (mode ?) broadband afforestation (mode ?), gaps 200 square meters (artificial aids) (mode V). pepper-growing areas (mode ?, ?) and used Cupressus funebris Endl. as CK.Research Methods by field observation and laboratory experiments combining after Cupressus funebris Endl forest transformation and surface runoff, soil erosion and soil physical and chemical properties of the transformation after study. The main results were found as follows:1. After three years of renovation, in 2014. the amount of soil erosion each transformation mode descending order as follows:Mode ?> mode ?> Mode ?> Mode ?> Mode ?> Mode ?> Mode ?. Each mode runoff from high in the end are arranged as follows:Mode ?> Mode ?> Mode ?> Mode ?> Mode ?> Mode ?> Mode ?. As can be seen from the results, the slope is the most important factor affecting soil erosion, pepper average slope (5 °) is far smaller than the other plots (30 °), runoff and soil erosion produced far less than other plots. With liu hao at the beginning of the transformation of research structure is slightly different, after three years of renovation, in addition to mode ?. the transformation pattern are played to reduce the effect of soil and water loss, improve the forest ecological benefit and comprehensive service, and model ? reformation has the most significant effect.2. The correlation analysis results:rainfall and runoff, soil erosion showed a positive correlation, Soil erosion and runoff there were very significant positive correlation between, indicating that the greater the greater the amount of soil erosion runoff.3. soil enzymes, microbes and soil properties affect soil erosion. Soil enzymes, the number of microorganisms, soil nutrient content, porosity, etc. exhibit leached layer> layer is deposited. Soil erosion with soil nutrient content, and increase the number of microbial activity is reduced. This study of soil enzyme and microorganism quantity and soil physical and chemical index and the correlation analysis between soil erosion, the soil enzyme, microbe quantity, organic matter content, total nitrogen, total porosity, permeability and significant negative correlation relationship between soil erosion between the organic matter content; (p< 0.05) soil bulk density and between soil erosion significantly positive correlation (p<0.05); There were no significant correlation between total phosphorus, effective phosphorus, available potassium, potassium, and nitrogen content and amount of soil erosion (p> 0.05). Soil nutrient content, organic matter, enzyme activity, and so are the number of microorganisms mode V maximum, minimum mode ?, consistent with the amount of soil erosion and runoff.4. Different transformation modes on soil physicochemical and chemical properties to improved significantly. In the present study, after three years of renovation, in addition to Mode ? (control), the various modes of soil total porosity, permeability, organic matter and total nitrogen content was significantly higher than that before the transformation etc, such as soil bulk density was significantly lower than before the transformation (p<0.05); Compared with the previous transformation, soil porosity increased 3.36%-8.83%; Permeability increases 5.83%-15.36%; increase soil organic matter content of 6.272%-38.477%; total nitrogen content of the soil increased 5.170% 14.127%?mode ? soil properties were not significantly changed.In summary, after the transformation, soil erosion was significantly reduced, and the most obvious decrease in mode ?. In a number of factors the effects of soil erosion, the slope of the greatest influence, pepper average slope (5 °) is far smaller than the other plots (30 °),runoff and soil erosion is far less than other plots; Rainfall and runoff, soil erosion is a strong correlation between rainfall to some extent determines the soil erosion. Soil nutrient content, organic matter, enzyme activity, and so are the number of microorganisms mode ? maximum, minimum mode ?, consistent with the amount of soil erosion and runoff, and soil improvement for forest rehabilitation to the best mode ?, description, ? manual mode window introducing native trees and camphor toon better able to play a role in soil and water conservation. Different transformation modes, to reduce soil erosion and improve soil function size is in turn:Mode ?> Mode ?> Mode ?> Mode ?> Mode ?> Mode ?> Mode ?. |
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