Valuing Multifunctionality Of Rice Ecosystem In China

With multifunctionality, the rice farming not only has the function of rice production, but also has ecological functions and social functions, while the ecological functions and social functions of paddy field with non-rival and non-excludability are not endowed proper market values and are neglected by the public, because it can not be traded in the market. The rice ecosystem with multifunctionality has the features of joint production, and closely relates to paddy field area and production intensity. In recent years, the area of Chinese paddy field has decreased gradually and the usage intensity of agricultural chemicals has been increased, which endanger the sustainable development of the rice agriculture. In order to protect the multifunctionality of rice ecosystem and realize the sustainable management of rice agriculture, it is necessary to formulate relevant policies to protect and make full use of paddy multifunctionality, while the recognition and evaluation of rice ecosystem function value is the premise of implementing policy intervention. Based on the six Chinese rice cropping region as the research object, Delphi method and analytic hierarchy process are used to get the cognitive situation of experts for the main functions of rice ecosystem, so that the thesis qualitatively evaluate the value of service functions of rice ecosystem; According to the main methods of existing cases for the value evaluation of multifunctionality of rice ecosystem and combined with the actual situation of Chinese rice production, it establishes the evaluation methods of multifunctionality value of rice ecosystem; The multifunctional monetary values of rice ecosystem of the six Chinese rice cropping region are evaluated by established evaluation methods. The results of this research are as below:(1) From two aspects of positive functions and negative functions, it selects the main indicators of value assessment of service functions for rice ecosystem. The positive functions include economic functions, ecological functions and social functions. The economic functions mainly are rice production and straw resource; ecological functions are flood control, fostering water resources, air purification, organic waste disposal, soil erosion prevention, collimation mitigation and biodiversity conservation; social functions are entertainment, scientific research and educational culture, employment security and food security. The negative function mainly includes the water resource consumption, greenhouse gas emissions and agricultural chemical pollution.(2)Qualitative evaluation results of service functions of rice ecosystem are:economic functions> ecological functions> social functions; rice production> straw resources> collimation mitigation> food security> flood control> employment security> fostering water resources> air purification> entertainment; the importance of soil erosion prevention, organic waste disposal and biodiversity conservation equals to the importance of flood control; and the importance of scientific research and educational culture equals to the importance of employment security. The negative influences of the water resource consumption and agricultural chemical pollution are greater than greenhouse gas emission.(3) It establishes quantitative evaluation system of service function value of rice ecosystem including market valuation method, replacement cost method, contingent value method and results reference method.(4) Quantitative evaluation results of service function value of rice ecosystem indicated that:①In2010, the multifunctionality value of Chinese rice ecosystem was about847.843billion Yuan, of which the positive function value was about897.977billion Yuan and the negative function value was about-50.134billion Yuan. The positive function value was nineteen times higher than the negative function value, and the multifunctional value benefit of rice ecosystem was remarkable.②The value ecological functions is the biggest positive functions, about449.361billion yuan, accounting for50%of the value of positive functions; economic function value is smallest, about168.289billion yuan, accounting for18.8%of the value of positive function; social function value is about280.327billion yuan, accounting for31.2%of the value of positive function. The order in accordance with the value magnitude of various functions is:ecological functions> social functions> economic functions. The total value of ecological functions and social functions is about729.688billion yuan,4.3times the value of economic functions.③From the positive functions, the value of rice production, air purification and employment security is greater, respectively118.476billion yuan,329.391billion yuan and142.795billion yuan, and the total value of them is about590.662billion yuan, accounting for66%of the value of positive functions; the value of fostering water resources, organic waste disposal, soil erosion prevention and collimation mitigation is smaller, respectively9.938billlion yuan,11.64billion yuan,4.799billion yuan and7.829billion yuan, and the total value of them is about34.206billion yuan, accounting for only3.8%of the value of positive functions. The order in accordance with the value magnitude of various functions is:air purification> employment security> rice production> straw resource> entertainment> flood control> food security> scientific research and educational culture> biodiversity conservation> organic waste disposal> fostering water resources> collimation mitigation> soil erosion prevention.④From the negative functions, the negative impacts of greenhouse gas emissions are greatest, about-39.266billion yuan, accounting for78.3%of the total value of negative functions; the negative effects of agricultural chemical pollution are smallest, about-17.75billion yuan, accounting for3.5%of the total value of negative functions; the value of the water resource consumption is about-9.093billion yuan, accounting for18.2%of the total value of negative functions. The order in accordance with effects of various functions is: greenhouse gas emissions> the water resource consumption> agricultural chemical pollution.⑤From the six rice areas, multifunctional value of rice ecosystem of Central China rice cropping region is the largest, about500.912billion yuan, accounting for57.7%of the total value; multifunctional value of rice ecosystem of Northwest China rice cropping region was the smallest, about7.192billion yuan, accounting for0.7%of the total value. The order of the six rice areas in accordance with multifunctional value is:Central China rice cropping region> South China rice cropping region>Northeast China rice cropping region> Southwest China rice cropping region> North China rice cropping region> Northwest China rice cropping region.⑥Through making comparative analysis of evaluation results of multifunctionality value research of seven rice ecosystem in China, it finds that economic functions and ecological functions are the main functions of rice ecosystem.⑦Through comparing with the evaluation results of multifunctionality value research of four rice ecosystem in Chinese Taiwan, Korea, Japan and Indonesia, it finds the ecological functions are the main assessment content of the multifunctionality of various regional rice ecosystem, but the value of the ecological functions endowed by the four regional rice ecosystem is different.From above, two conclusions have been drawn:(1) The non-market value of ecological functions and social functions of rice ecosystem is far higher than the market value presented by its production function.(2) The production benefits, ecological benefits and social benefits of rice ecosystem are significantly larger than the effects of the negative externalities caused by rice production activities.