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 ...