Assessment Of Ecological Service Value Of Farmland Ecological Rehabilitation In Danjiangkou Reservoir Area

Danjiangkou reservoir is the core water source area of the middle route of the South-to-North Water Transfer Project.The quality of the ecological environment around the reservoir is not only related to the quality of the north-to-north water transfer project,but also related to the long-term public security of the economic and social development of the water receiving areas in northern China.However,the quality of the ecological environment around the reservoir area has been damaged,among which the pollution of agricultural sources is one of the important reasons for the decline of its quality.In recent years,in order to pursue grain yield,people have planted single crops in farmland for a long time and in a large area,and applied a large amount of pesticides and chemical fertilizers,which has seriously damaged the soil quality,resulting in the continuous destruction of farmland biodiversity and ecological environment.In view of these problems,the reservoir area has carried out farmland ecological transformation and other measures to improve the quality of farmland ecological environment,but there is a lack of corresponding evaluation,The value evaluation of ecological service function is the main evaluation method of the environmental quality of farmland ecosystem,which can effectively reflect the environmental status of ecosystem.Therefore,this paper selects the farmland of six counties and cities in Danjiangkou as the research scope,studies the potential impact of these ecological measures on the environmental quality of farmland ecosystem,and evaluates the potential value of these measures in farmland ecosystem.According to the statistical data of the study area in 2019,rice,wheat,corn,vegetables,tea gardens and orchards are selected as the evaluation objects.According to the ecological service value evaluation theory,the market value method,shadow price method,water balance method and other methods are used to evaluate the impact of these ecological measures on grain production,water conservation,carbon fixation,oxygen release,nutrient conservation,soil conservation and biodiversity conservation in Danjiangkou reservoir area The value of 8 ecosystem services such as pollination.The results show that:(1)After the ecological farmland transformation technology,the planting area of crops has not changed,and the planting of green manure plants in orchards has increased.The ecological transformation around farmland,orchards and tea gardens and the planting of crops in idle land in orchards have increased the planting area of green manure plants and trees to varying degrees.(2)Under the traditional farmland planting mode,in 2019,the service value of rice,wheat,corn,vegetables,tea gardens and orchards in Danjiangkou reservoir area was 1.414 billion yuan,1.768 billion yuan,1.742 billion yuan,10.376 billion yuan,5.062 billion yuan and 10.964 billion yuan respectively,with a total of 31.326 billion yuan,including 15.457 billion yuan of supply service value,11.448 billion yuan of regulation service value and 4.421 billion yuan of support service value.The sum of regulation function and support function is greater than supply function,which shows that the supply function of farmland is based on the good state of ecosystem.It shows that people should pay attention to the comprehensive environmental benefits of farmland ecosystem in land use,so as to improve agricultural output value and the surrounding ecological environment.(3)Through the ecological farmland transformation technology,the farmland ecological service value of Danjiangkou reservoir area has increased to varying degrees.The service value of rice,wheat,corn,vegetables,tea gardens and orchards has increased to RMB 1.570 billion,RMB2.229 billion,RMB 2.148 billion,RMB 11.158 billion,RMB 5.285 billion and RMB 13.933 billion respectively,totaling RMB 36.323 billion,of which the supply function value is RMB16.412 billion and the regulation service value is RMB 13.59 billion,The value of support services is 6.321 billion yuan.The total added value was 5.834 billion yuan,of which the supply function increased by 955 million yuan,the regulation service increased by 2.979 billion yuan and the support service increased by 928 million yuan.The research shows that the ecological farmland transformation technology greatly increases the biodiversity of farmland and improves the quality of soil environment on the basis of meeting people’s food needs.It is of great practical significance to maintain a good farmland ecological environment in Danjiangkou reservoir area.It also provides a certain technical support for the sustainable development of the later South-to-North Water Transfer Project and promoting the technology in a large area throughout the country.The research shows that the ecological farmland transformation technology greatly increases the biodiversity of farmland and improves the quality of soil environment on the basis of meeting people’s food needs.It is of great practical significance to maintain a good farmland ecological environment in Danjiangkou reservoir area.It also provides a certain technical support for the sustainable development of the later South-to-North Water Transfer Project and promoting the technology in a large area throughout the country.