The gradient paradigm: A conceptual and analytical framework for landscape ecology

Abstract

Landscape ecology deals fundamentally with how, when, and why patterns of environmental factors influence the distribution of organisms and ecological processes, and reciprocally, how the actions of organisms and ecological processes influence ecological patterns (Urban et al. 1991; Turner 1989). The landscape ecologist's goal is to determine where and when spatial and temporal heterogeneity matter, and how they influence processes. A fundamental issue in this effort revolves around the choices a researcher makes about how to depict and measure heterogeneity (Turner 1989; Wiens 1989). Indeed, observed patterns and their apparent relationships with response variables often depend on the scale that is chosen for observation and the rules that are adopted for defining and measuring variables (Wiens 1989; Wu and Hobbs 2000; Wu and Hobbs 2004). Success in understanding pattern-process relationships hinges on accurately characterizing heterogeneity in a manner that is relevant to the organism or process under consideration.