Spatial heterogeneity in ecological systems
生态学系统的空间异质性

Spatial heterogeneity in ecological systems is a common understanding of ecologists. The importance of spatial heterogeneity in ecology lies in its ubiquity as a feature of ecosystems and in the ecological effects it raises. Spatial heterogeneity, the complexity and/or variability of ecological systems in space, associates with scale. The degree to which heterogeneity is expressed depends on scale. The hierarchical theory throws light on understanding spatial heterogeneity in ecological systems. Ecological systems can be seen as multi-scale hierarchical mosaic patches. Many quantitative methods, such as nested quadrat analysis, semivariograms, fractals, trend-surface analysis, spectral analysis, etc. provide powerful tools to describe spatial heterogeneity. Spatial heterogeneity has very important influences on both abiotic and biotic processes. Most organisms are benefited from environmental heterogeneity. Modeling and experimental studies over landscape scale is a new challenge to ecologists in studies of dynamics of spatial heterogeneity. Experimental studies on striding across boundaries between landscape patches of some clonal plants can link researches on behaviors of plant individuals and dynamics of patches and landscapes. In the future, defining a system appropriately within which heterogeneity is analyzed and identification of appropriate null models for studies of the effects of heterogeneity are important issues.