Change pattern,process and landscape ecological significance in ecotone of agriculture and grassland in north China

Proceeding from landscape ecology, the change pattern, process, dynamic mechanism and effects on regional agricultural development in ecotone of agriculture and grassland in north China were studied. The agricultural development and the fluctuation of boundary of agriculture and grassland in china, the climatic change in ecotone of agriculture and grassland and the alternative replacement of agriculture and busbandry, and the landscape ecologic significance of ecotone of agriculture and grassland are expounded.The limited fluctuation of boundary of agriculture and grassland and the replacement of agriculture and husbandry alternatively were correspondent to the replacement of dry and wet climate and the growth and decline of farming and drift husbandry economics alternatively. In addition that the ecotone of agriculture and grassland has the fragile characteristics in environment, there was obvious heterogeneity formation and flowing out in agricultural landscape and their effects on agricultural techniques and development of adjacent regions.