黄土高原草原景观斑块形状的指数和分形分析  

Patch Shape Indices and Scale fractal Analysis of Steppe Landscape in the Loess Plateau

作　　者：李斌[1] 张金屯[2] 

机构地区：[1]中北大学化工与环境学院,山西太原030051 [2]北京师范大学生命科学学院,北京100875

出　　处：《草地学报》2010年第2期141-147,共7页Acta Agrestia Sinica

基　　金：国家自然科学基金项目(30070140)资助

摘　　要：利用地理信息系统技术结合景观斑块形状指数和分形分析方法,对黄土高原地区草原景观斑块的形状以及空间特征进行了分析。结果表明:黄土高原地区45种草原景观斑块形状指数相差悬殊,垂穗披碱草(Form. Elymus nutans Griseb.)草甸草原和川青锦鸡儿(Form. Caragana tibetica Kom.)草原的斑块圆环度指数之差达到20.8460,反映出黄土高原草原景观斑块的边界率相差较大,表明草原景观斑块与外界的物质、能量交换活跃程度相差较大。草原斑块的形状明显偏离于圆形和方形,为不规则形,这与黄土高原地区破碎的地形密切相关。不同类型草原景观斑块分维数变化较大,早熟禾(Form. Poa sphondylode Trin. ex Bunge)草甸草原的分维最大,其格局是最为复杂的。多根葱、大苞鸢尾(Form. Allium polyrhizum Turcz. ex Regel and Iris bungei Maxim.)草原的分维最小,其格局是最简单的。这些都反映出黄土高原地区草原景观异质性较大。Because of the influence of drought and windy climate and the poor soil structure,soil erosion and land desertification are the serious problems in Loess Plateau and the ecological environment is sensitive to disturbance.However,the malignant circulation of steppe destroying,soil erosion,and land desertification is dominant in Loess Plateau steppe.It is important to study the patch shapes and their spatial distribution in steppe landscape for the scientific management of Loess Plateau.Based on the information from Loess Plateau Vegetation Map（1∶500,000） and Geographical Information System in combination with the landscape patch shape indices and scale fractal analysis,this paper studied the patch shape and their spatial distribution of steppe landscape in Loess Plateau.The results show that the significant differences were detected among the patch shape indices of the forty-five steppe landscapes in Loess Plateau.The difference between the patch shape indices of Form.Elymus nutans Griseb.meadow steppe and Form.Caragana tibetica Kom.steppe was 20.8460,which illustrates that the exchange degrees between the steppe landscape patches and surrounding physics and energy are comparatively different with great patch boundary length.The shapes of steppe patches were irregular and obviously deviated from both circle and squire and closely correlated with the heterogeneity of steppe landscape in Loess Plateau.The fractal dimensions of different steppe patches varied greatly.Form.Poa sphondylode Trin.ex Bunge meadow steppe had maximum fractal dimension with the most complicated pattern and Form.Allium polyrhizum Turcz.ex Regel and Iris bungei Maxim.steppe had minimum fractal dimension with the simplest pattern.In summary,the non-uniformity of steppe landscape in Loess Plateau is comparatively great.

关 键 词：草原景观 形状指数 分形分析 黄土高原 

分 类 号：Q149[生物学—生态学] S812[生物学—普通生物学]