农牧交错地带的生态评估对土地整理的启示

开展农牧交错地带的生态评估,不仅能够保障区域内的粮食安全和生态安全,更能启示未来的土地整理工作。利用1986、1996和2000年的3期Landsat数据,应用转移矩阵、生态服务功能分析和景观格局分析等研究方法,对地处典型农牧交错带的镇赉县的土地利用变化、土地利用格局和功能进行研究,结果表明:耕地和草地是研究区域中最主要的土地利用类型;1986～1996年间土地整理工作的重点是耕地与未利用地之间的转变,1996～2000年间土地整理工作的重点是耕地与草地之间的转变。土地形态整理必然引起生态系统服务功能价值的变化,随着研究区域生态环境的退化,对于土地整理过程中不可控制单元(如湿地和水域)的微小变化,必然造成生态系统服务功能价值大幅变动。因此,系统维护与保育整个生态系统,实现整个区域的生态型土地整理,是今后土地整理工作的重点和难点。

Revelation of Ecological Evaluation of the Farming-pastoral Transitional Zone to Land Arrangement--A Case Study on Zhenlai County

The objective of this study is to provide a scientific enlightment for future ecological land use arrangement that can not only ensure the food supply,but also protect the eco-environ-mental quality,in the transition region of the farming-pastoral zone,through prohibiting from exploiting blindly wetlands and reclaiming farmlands from lakes.Although the concept of land arrangement is firstly provided in Land Management Law of the People's Republic of China enacted in 1998,the works of land arrangement (such as land development and renovation,land reclamation) have already been unfolded for a long time.Through the analysis of land use changes from 1986 to 2000,the traces of land arrangement are derived.At the same time,the ecological evaluation of land use changes will provide a scientific basis for future land arrangement work.Zhenlai County,the typical transitional belt of the farming-pastoral zone in the west of Jilin Province,is chosen as a case study area in this paper.Based on the interpretation of Landsat data,which are distilled from digital images taken in 1986,1996 and 2000 respectively,the land use and land cover changes are studied,the analysis of shape readjustment and the evaluation of the ecosystem services function of readjustment in Zhenlai County are unfolded applying the transitional matrix,landscape pattern method and ecosystem services function method.The preliminary results are as follows:1)Farmlands and pastoral land are the main land use categories in Zhenlai County;2)from 1986 to 1996,the work emphasis on land arrangement is the transformation between cultivated land and unused land,such as consolidating farm plots and developing unused land;3)and from 1996 to 2000,the work emphasis is the transformation of farmlands to grasslands.The land use arrangement will be bound to lead to the value changes of ecosystem services function,but with the degradation of eco-environment,the tiny changes of uncontrolled unit,such as wetland and water area,will induce the prodigious transformation.So the future focus and difficulty are to realize the ecological land arrangement from the point of view of cultivating ecosystem.