Conversion of farmlands to forests and grasslands (CFFG) is one of the major ecological projects with the largest investment, strongest policy, widest coverage and highest degree of participation in China, and even in the world. In order to scientifically evaluate the benefits and dynamic changes, better serve the decision-making, consolidate the achievements and promote the high-quality development of this project, it is of great significance to organize the monitoring and evaluation of its benefits. On the basis of reviewing and summarizing the monitoring and evaluation history of the benefits, this study established an indicator system for comprehensive monitoring and evaluation, composed of three components of benefits, 10 categories and 48 indicators, including 23 indicators of ecological benefits, 11 indicators of economic benefits and 14 indicators of social benefits. These methods of monitoring and evaluation are applied to the systematic and full coverage monitoring and evaluation of the national project of CFFG for the first time. There are four aspects of the innovation of this research: First, it is the first time that a comprehensive ecological, economic and social benefit evaluation indicator system has been established. Second, it is the first time that quantitative evaluation methods have been established. Third, it is the first comprehensive quantitative assessment of the CFFG project. Fourth, this is a full-scale evaluation of the project for the first time. The evaluation results show that the total value of the three benefits from the CFFG project is 2405.046 billion Yuan (354.4129 billion US$)·y-1, of which the ecological benefit is 1416.864 billion Yuan (208.7922 billion US$)·y-1, the economic benefit is 255.486 billion Yuan (37.649 billion US$)·y-1 and the social benefit is 732.696 billion Yuan (107.9717 billion US$)·y-1, accounting for 58.92%, 10.62% and 30.46%, respectively, of the total benefits. Our results provide detailed evaluation of the achievement and benefits of the CFFG project.
Keywords: comprehensive benefits; conversion of farmlands to forests and grasslands; indicator system; monitoring and evaluation.