实施三峡工程以来,三峡库区森林空间分布及其景观格局发生了显著变化,非常值得关注。研究以三峡库区遥感解译的1990、2002、2011年3期森林分布数据为基础,建立森林破碎化分析模型,运用ArcGIS10.0和Fragstars4.0软件,选取合适的景观格局指数,对库区森林景观格局动态和破碎化进行了分析。结果表明:1990~2011年间,三峡库区森林斑块面积和数量明显增加,斑块间异质性减弱;2011年森林面积比例超过70%的地理网格单元达40%,比1990年提高15%;森林景观聚集度、优势度升高,团聚性不断增强,破碎化程度明显改善,森林生态系统稳定性增强。由此证明,在长期的人工造林等植被建设和保护工程作用下,能够促进森林景观格局的改善,减缓森林景观破碎化,增进森林生态系统的复杂性和稳定性。
Since the initiation of Three Gorge Construction Project,the spatial distribution and landscape pattern of forests in the areas have changed significantly,which is worthy of major concerns.In order to monitor the dynamics and fragmentation of forest landscape pattern in the area,based on the remote sensing interpretation data of forests in the years of 1990,2002 and 2011,the appreciate landscape pattern indexes were selected to build the models for forest fragmentation by using the software ArcGIS10.0 and Fragstats4.0.The results are shown as followings.From 1990 to 2011,with the increases of patch area in size,number,aggregation and dominance,the heterogeneity and fragmentation decreased on the contrary.The stability of forest ecosystem in the studied area was enhanced significantly.By the year of 2011,the grid cells of forest area proportion over 70% was up to 40 percent,higher 15% than that in 1990.It is concluded that,in order to relieve the fragmentation of forest landscape,it is an effective way to promote the improvement of forest landscape pattern by developing long-term planning of reforestation planting and vegetation construction,so that to enhance the complexity and stability of forest ecosystem.