Land Use Change and Its Ecological Effect in the Ecotone of Northwest of Yunnan Province, China: A Case Study of Yongsheng County
滇西北生态脆弱区土地利用变化及其生态效应 ——以云南省永胜县为例

Research on land use/land cover change and associated effects on eco-environment is the key content of geographical research on global change today. And ecosystem services are the hot issues of ecology and ecological economics. In this paper, we put ecosystem service values in use to weigh the ecological values of corresponding land use types, so as to evaluate the ecological effect of regional land use change. Yongsheng county, situated in the northwest of Yunnan province, also an ecotone, is taken as our research area. Based on TM images in 1988, 1994 and 1999, the landscape component maps of Yongsheng county were conducted through methods of supervised classification and interactive modification. The landscape type transition matrix and three kinds of indices for spatial patterns including patch-level index, class-level index and landscape-level index were calculated by models and GIS to examine the spatial patterns and dynamics of regional landscape in Yongsheng county. The results show that, due to human activity, the unused land decreased rapidly during the past 12 years; because of the limitation of physical geographic condition, the proportion of steady farmland is not high; the inter-changes of farmland and unused land happened frequently. And index for landscape diversity has showed a tendency of increasing, which means that the proportion of each landscape component changed to average. Also, the decreasing of fractal dimension of unused land shows that human activity effects are increasing. And land use change in Yongsheng county from 1988-1999 has got a good ecological effect, where the ecological benefit of land use is always increasing, and shows a distinct spatial difference.