The Function Of Water And Soil Conservation And Its Ecological Environmental Responses,in Hilly And Mountainous Regions Of South,China

Assessment of ecosystem services is the base of scientific managing ecosystem and sustainable using natural resources. Today, ecosystem services and how to assess their values have become the researching hot spots in the fields of ecology and eco-economics. The ecosystem function of water conservation and soil conservation are analyzed in the southern hill and mountain area in this paper, based on the ecosystem types data of2000,2005and2010, and used physical and value assessment methods. The study provides preliminary analysis on the variation characteristics of water conservation and soil conservation. On this basis, through the correlation analysis, this paper explores the impact of the water conservation and soil conservation on the water environment. The results show that:(1)The total amount of water conservation presents an upward trend and its total increase by1.61×108m3, increase the economic value of1.08×108yuan during2000-2010. Total amount of water conservation has a significant difference among different ecosystem types with a decreasing order:forestland> farmland> shrub> grassland> wetland. While the capacity of water conservation has a significant difference among different ecosystem types with a decreasing order:wetland> forestland> grassland> shrub> farmland. From the aspect of change trend, the function of water conservation forestland and grassland is on the rise, while the ecosystem of wetland, farmland and shrub varying degrees of decline.(2) The total amount and the economic value of soil conservation presents an upward trend and its total increase by7.68×108t, increase the economic value of264.37×108yuan during2000-2010. Total amount of soil conservation has a significant difference among different ecosystem types with a decreasing order:forestland> shrub> farmland> grassland> wetland> town> bare land. While the capacity of soil conservation has a significant difference among different ecosystem types with a decreasing order:wetland> grassland> shrub> forestland> farmland> town> bare land. From the change trend of different ecosystem types, in addition to the soil conservation function of bare land has no obvious changes, the rest of the ecosystem have different degree of rise.(3)As a whole, the ecosystem function of water conservation and soil conservation has improved in the study area, where forestland, farmland and shrub play a decisive role, but forest ecosystem play a leading role. Due to the impact of the transfer of ecosystem types, the different grades of water conservation and soil conservation shift from one to another level, but the main transfer is from the low level to the high level, which indicate the change characteristics in the whole study region.(4)The ecosystem function of water conservation and soil conservation has a high degree of influence on the ecological water environment in the study area, the absolute value of the correlation coefficient r greater than0.8, and its significant level above95%. From the view of different ecosystem, forest, grassland, wetland, farmland and shrub have a higher impact on water environment, including forest, grassland, shrub ecosystem has a strong ability to regulate hydrology and erosion control, but forest ecosystem is the most significant impact, its remarkable level of more than99%.