近54a扎龙自然保护区景观斑块面积变化特征

Variation Characteristics of Landscape Patch Area of Zhalong Nature Reserve in Recent 54 Years

运用GIS技术和景观生态学的数量分析方法,根据扎龙自然保护区土地利用类型图和LandsatTM图像,分析了1950—2004年保护区景观斑块面积变化特征。结果表明,54a间,保护区各景观类型以沼泽地所占面积比例最大,区域呈现出以沼泽地景观为基质,草地、耕地和未利用地等为主体的交错景观格局,其他景观类型呈补丁状散布于其中。沼泽地面积表现为波动性增加,草地面积下降显著,未利用地、住宅用地和耕地总体呈快速扩张趋势,水域面积变化不显著,林地所占比例最小,但呈上升趋势。面积加权平均值由大到小依次为沼泽地、草地、耕地、未利用地、水域、住宅用地和林地。最大斑块指数由大到小依次为沼泽地、草地、耕地,其他各类景观的最大斑块指数均小于1。斑块面积标准差最大的是沼泽地,并呈逐年增大趋势,水域、林地、住宅用地等景观类型斑块面积差异程度较小。斑块面积变异系数最大的是1978年的住宅用地,林地、未利用地的斑块面积变异系数较稳定。

In order to provide theoretical basis for planning,designing and species conservation of the Zhalong Nature Reserve,changes of the reserve in landscape patch area from 1950 to 2004 were analyzed,based on related land use maps and Landsat TM images and with the aid of the ecological quantitative analysis method and GIS technology.The following was found.The marsh landscape dominated the reserve in area in the 54 years,marsh-based mixed landscapes of grassland,cropland or unused land,appeared in parts of the reserve,and some other types of landscapes scattered in patch amid it.The area of marshes increased though somewhat fluctuated,while the area of grassland decreased significantly,the areas of unused land,residential land and cropland in general increased quickly,the area of water surface remained almost unchanged,and the area of forestland was the least in proportion,but showing an increasing trend.In terms of area weighted average,the landscapes followed a decreasing order of marsh grassland cropland unused land waters residential land forestland,and by largest patch index marsh grassland cropland all the other types of landscapes,with index lower than 1.The patch size standard deviation of marshes was the largest and increased year by year,and that of waters,forestland and residential land were rather small.The patch size variance coefficient of the landscape of residential land was the largest in 1978,and that of forestland and unused land was quite stable.