基于遥感的东北农牧交错区景观格局与变化研究——以吉林省长岭县为例

Landscape Patterns and Changes of Farming-Pastoral Zone in Northeast China Based on the Remote Sensing Data——A Case Study of Changling County of Jilin Province

根据 1980年和 2000年的两期Landsat-MSS、Landsat-TM数据,应用景观空间格局指数分析了地处东北农牧交错带的长岭县景观结构及其变化特征。结果表明:耕地始终是研究区域内的基质景观;该地最显著的变化为高覆盖度草地面积的大量减少,耕地和盐碱地面积的增加;各景观类型的斑块在大小上有很大差异;多样性和均匀性减少,景观异质性程度下降。

The transitional region between cropland in semi-humid region and grassland (pasture) in semiarid region, is an important ecological barrier, which prevents the desert from extending into the plains of the eastern China. It is also a region with severe environmental problems such as desertification, vegetation degradation and salinization due to its natural fragility enhanced by human activities. The study on landscape spatial pattern provides valuable information for rational management of the environmental resources. And it has been one of the key study areas in landscape ecology as a whole. In this article we choose Changling County of Jilin Province as a case study area to present the changing feature of landscape patterns. Changling County is a typical region of farming-pastoral zone in Northeast China, located in the region of 43°59′-44°42′N, 123°06′-124°45E′, covers a total area of 5737.9 km2. By applying satellite imageries of different years, Landsat-MSS in 1980, Landsat-TM in 2000 respectively, we analyze the changing feature of landscape patterns in the study area according to the patch-size, spatial pattern, and other index. The study shows that the farmland covering over 50% of the study area is the matrix both in 1980 and 2000. The most remarkable changes in landscape pattern are the obvious decreasing by 55.46% of high-covered grasslands and the increasing by 26.61% of farmlands and salina. The different landscape types had different scales in their patch-size, and the landscape pattern had a trend of decreasing diversity and increasing dominance. The impact of human activity and study area's natural conditions combining together are the leading factors that induce the degradation and salinization of grassland.