摘要
植被是一个地区植物群落的总体,是对于生态环境因素的综合反映。植被在空间上的分布是典型的分维数体,它在空间所有尺度上都有细节。在许多情况下分维数具有某种形式的自相似性,即它不随尺度的增加或缩小而变化,它独立于尺度。因此比较不同尺度上树种的空间格局与其对应的分维数值,可以对不同尺度上的空间格局有一个全面的了解。通过变异函数计算出的格局的分维数值可以描述不同尺度上空间格局的拓扑学性状和自相似性,可以很好地揭示植被的空间异质性。
Vegetation is a collectivity of the phytocommunity in a region and is a synthetical reflection about the ecological environment. The spatial distribution of the vegetation is a typical fractal object and show details in different scales. The fractal dimension always embodies self-similar characteristics which means they don＇t change with the scales. Consequently, comparing the spatial pattern and the fractal dimension between different scales will make us understand the spatial pattern roundly. Based on regionalized variable theories, geostatistics is one kind of spatial statistical theory used to explore the correlativity and dependence between＇spatial variables. The first characteristic of this method is its emphasis on the importance of spatial dependence of variables. In practical research, semi-variance values of ecological factors or other indices can be calculated from the semi-variance formulate according to the theory, and then, semi-variogram can be drawn, distribution characteristic of the vegetation （such as clumped or uniform pattern）can be found from the graph. Mathematical models simulation should be used in quantification of this characteristic. The fractal dimension which was calculated by double-logarithm semi-variogram, where m （the slope of the graph） shows its heterogeneity characteristic as well. The lower the D value is, the higher heterogeneity the distribution of vegetation has.
出处
《水土保持研究》
CSCD
北大核心
2007年第1期155-158,共4页
Research of Soil and Water Conservation
基金
成都信息工程学院院选科研项目(编号:CRF200520)
国家自然科学基金资助项目(项目号:40201037)
关键词
植被
空间异质性
分形几何学
半方差
多尺度
vegetation
spatial heterogeneity
fractal geometry
semi-variance
multi-scale
