吉林省东部山区近50年森林景观变化及驱动机制研究

Changes of forest landscape and its driving mechanism during the last fifty years in the eastern mountain area of Jilin Province.

在RS与GIS的支持下,综合集成遥感影像(TM、MSS)与地形图在专家知识的参与下重建吉林省东部山区1954、1976和2000年土地利用/覆盖变化信息,结合景观生态学理论分析研究区森林景观时空变化特征,进一步从森林变化的自然因素、空间区位作用因素和社会经济因素3个方面分析森林变化的驱动机制.研究结果表明,吉林省东部山区森林变化总体上呈先减少后增加的“V”形趋势.由于1976年前的毁林开荒与1976年后“封山育林”的影响,森林景观破碎化程度先增加后减少;研究区以林地—耕地,林地—草地为主要转换类型,延边朝鲜族自治州是集中变化区域;林地的变化主要发生在坡度较缓、高程较小、土壤条件相对较好的低山或平原区;林地的变化随距离城乡居民地和道路的距离呈指数衰减.自然保护区与生态功能区建设对森林景观的生态保育功能具有积极的作用.林地变化主要包括3个层次的驱动因素,人口增长与经济发展的需求以及国家林业政策的失误是林地减少的主要驱动因素;森林生态保育政策的引导是林地增加的最主要的驱动力;自然因素、距离城乡居民用地和道路的距离是林地变化空间区位选择的重要影响因素.

The authors reconstructed the information of land use/coverage change（LUCC） in 1954, 1976 and 2000, integrating TM, MSS and topographic map with expert knowledge in the eastern mountain area of Jilin Province based on RS and GIS. Then the spatial-temporal changing characteristics of forest landscape combining with landscape theory and its driving mechanism from natural factors, spatial postition factors and social economic factors were analyzed. The conclusion was that the forest area decreased and then it increased in the eastern mountain area of Jilin Province from 1954 to 2000. Owing to reclaiming the forestland before 1976 and protecting forests in the mountain areas after 1976, the fragmental index of landscape increased first and then decreased. Main conversion types of woodland change were forestland-farmland and forestland-grassland, and Yanbian Korean Autonomous Prefecture of Jilin Province was the main area of forest change. Woodland change mainly took place in the area of low hill and plain, whose elevation was 300-900 m and grade was 0°-11°. The woodland change took exponential attenuation with distances from village and road and the forests were protected in the natural reserve and eco-function areas. Forest changes came from three levels of driving forces, i. e. the woodland demand with population increase and economic development, and the wrong forest industry policy were the main driving factors of forest decrease; the forest protection policy was the main driving factors of woodland increase; and the natural factors, the distances from town, village and road were important and influenced factors of spatial position selecting. Koy words forest landscape, landscape ecology, RS, GIS