Ecosystem Service Function And Value Evaluation Of Paddy Under Different Planting And Breeding Modes

The function and value evaluation of ecosystem services are important research method and hotspots.As a typical artificial wetland ecosystem,the paddy ecosystem has both the functions of a farmland ecosystem and a wetland ecosystem.The planting and breeding in paddy field has significantly enhanced its wetland ecological function,but its ecological service function and value have not been taken seriously.Therefore,this study constructed paddy ecosystem service value evaluation indicators based on CICES（V5.1）,and evaluated the service value of five paddy ecosystems:rice monoculture mode（CK）,rice-shrimp mode（RC）,rice-duck-shrimp nomadic duck mode（NRCD）,rice-duck-shrimp unit mode（CRCD）,and rice-duck-shrimp large field mode（BRCD）.The research results are as follows:The service functions of paddy ecosystem mainly include direct product supply,carbon sequestration and oxygen release,climate regulation,air purification,water conservation,water storage and flood control,soil organic matter accumulation,solid waste consumption,biodiversity maintenance,and landscape aesthetics.In addition,considering its negative ecological costs,including water resource consumption,greenhouse gas emissions,and agricultural chemical pollution.The total value of paddy ecosystem services in CK,RC,NRCD,CRCD,and BRCD were 104,156 yuan·hm^-2,135,892 yuan·hm^-2,137,701 yuan·hm^-2,140,480 yuan·hm^-2,139,645 yuan·hm^-2,respectively.Compared with CK,the ecosystem service value of the paddy planting and breeding modes increased by an average of 32.9%,and compared with RC,the ecosystem service value of the rice-duck-shrimp mode increased by an average of2.5%.The ecological value accounted for 70.3%-81.0%of the total value in the five different paddy ecosystem modes,and the climate regulation function has the highest value.The regulation and support services in CK accounted for 81.0%of the total value,which is 4.79times the direct production value.In RC,NRCD,CRCD,and BRCD,the product supply value accounted for 27.4%,27.5%,27.5%,and 28.2%of the total value,respectively,and still dominates the total value.The indirect ecological value accounted for 71.1%,70.0%,70.0%,and 70.3%of the total value,respectively,with an average of 2.54 times the direct economic value.Among them,the value of climate regulation,water conservation,and water storage and flood control services occupied the first three.In the environmental costs of paddy ecosystems,water resource consumption and greenhouse gas emissions during the rice season accounted for 78.3%-92.3%.This study mainly indicated difference trend between different planting and breeding modes and conventional rice monoculture.After comprehensive consideration of 13positive and negative ecosystem service functions of paddy fields and horizontal comparison of ecosystem service values of 4 different paddy planting and breeding modes,the CRCD had the highest ecosystem service value.This study enriches the cultivation mode of paddy fields and provides a new idea for cultivation ecosystem of paddy fields.