Abstract:

Study on farmland non- agriculturalization and its control mechanisms is becoming an important issue in the framework of LCS ( Land Change Science), a new developing conception by IGBP. LCS stresses not only research on LUCC itself but also other relevant social- economic problems and pays much attention to high- speed change areas all over the world. China, a fast developing country, is facing many land use problems brought by fast economic growth, urbanization and industrialization with fast farmland losing as a core. Taking the capital of China, Beijing, as a case, the temporal- spatial processes of farmland conversion and its control mechanisms are discussed. It is found that ( 1) Farmland losing is the main character of land use in Beijing from 1996 to 2004; ( 2)Among various factors threatening the sustainability of farmland, the most outstanding and the most serious one is the occupation on farmland for urban development;( 3) The lost farmland is mostly those high quality land in the plain area; and ( 4) Farmland losing is driven by population increase, economic growth, some local governments'acts for short- term benefits from farmland conversion and so on. In order to moderate the conflicts between farmland conservation and urban development in Beijing and other fast developing districts in China, the authors claim that the following points should be emphasized in land management:( 1) Importance should be especially placed on the quality of farmland; ( 2) Policies on farmland conservation, such as "keeping quantity balance", should be reviewed; and ( 3) It is necessary to make appropriate control mechanisms for farmland conservation, including: to provide a reasonable threshold of farmland conservation, to establish appropriate legislation, institutions and mechanisms, and to avoid illegal occupation on farmland for urban development, etc.

Key words: Beijing, China, control mechanisms, farmland losing, LCS (Land Change Science)