作　　者： ; ; ; ; ;

机构地区： 亚利桑那州立大学

出　　处： 《生态学报》 2003年第11期2219-2231,共13页

摘　　要： 景观格局指数是量化描述景观格局特征的主要方法之一 ,各种格局指数的尺度依赖性使比较分析景观格局特征和尺度推绎复杂化 ,分析不同指数随空间幅度变化的一般行为有助于景观格局分析结果的解释和降低空间尺度推绎的复杂性。研究以 2种真实景观和 2 7种模拟景观为分析对象 ,考查了 1 6种常用的景观水平格局指数随空间幅度变化行为。根据这些指数因幅度变化行为可预测性把它们分为两类 :第 1类随幅度变化可预测性强 ,指数与幅度之间的关系可用简单的函数关系来表达 ;这类指数包括缀块数、边界总长、景观形状指数和缀块丰度密度 ;前两者随幅度增加呈幂函数形式增加 ,而缀块丰度密度随幅度增加呈幂函数下降 ,景观形状指数随幅度增加呈直线增加。第 2类指数随幅度变化的可预测性较差 ,指数随幅度的变化存在多种可能 (不同形式的增加、减小或保持不变 ) ,不可用一种或多种简单的函数关系来描述所有的情况。这类指数包括缀块丰度、缀块密度、边界密度、最大缀块指数、平均缀块面积、缀块面积标准差、缀块面积变异系数、平均缀块形状指数、面积加权平均缀块形状指数、双对数回归分维数、聚集度指数与Shannon多样性指数。第 2类指数随幅度的变化行为受景观格局特征和指数本身算法的影响。总体上来说 ,第 Scale and scaling issues represent one of the foremost frontiers of landscape ecology and ecology in general. There is an urgent demand for ecological information at finer/smaller scales to be transferable to coarser/larger scales. Understanding spatial heterogeneity is one of the essential challenges of spatial scaling. We refer scale to spatial extent in this study. Several ecologists had demonstrated that changing extent could influence the results of spatial pattern analysis. But only a few landscape indices with a relatively narrow range of extents were analyzed. In our previous studies,we analyzed four real landscapes of USA to illustrate the effects of changing spatial extent on landscape pattern analysis. The main goal of this study was to validate the general scaling relations derived in Wu et al .(2002) and Wu(2003) by anoryzing an additional complex Chinese landscape and a number of sumulated landscapes. Two real landscapes, the Northern Guangdong vegetation landscape (GDV) and the Phoenix urban landscape (PHX), USA, and 27 simulated landscapes generated by the SIMMAP neutral landscape model were chosen for analysis. The two real landscapes were both derived from LANDSAT TM remote sensing images with a grain size of 30 by 30 meters and an extent of 3651 4 km 2 for PHX and 8944 3 km 2 for GDV. Three factors were considered in generating the simulated landscapes maps. They were number of classes (2, 5, 10), class dominances (equal, one dominated, and systematically decreasing) and spatial distribution characteristics (clumped, moderately clumped, and random). All simulated landscapes had an extent of 750 by 750 pixels. Each of the 29 landscapes was clipped into smaller ones by decreasing the extent by 100 × 100 pixels each time. Sixteen commonly used landscape indices were computed for each of the 233 landscapes using a landscape pattern analysis software package, FRAGSTATS. A suite of scalograms and scale effect curves were drawn for analyzing the scale effects and deriving general scal

关 键 词： 空间幅度 尺度效应 景观指数 格局分析

领　　域： [生物学] [生物学]