A HIERARCHICAL FRAMEWORK FOR STREAM HABITAT CLASSIFICATION - VIEWING STREAMS IN A WATERSHED CONTEXT

Classification of streams and stream habitats is useful for research involving establishment of monitoring stations, determination of local impacts of land-use practices, generalization from site-specific data, and assessment of basin-wide, cumulative impacts of human activities on streams and their biota. This article presents a framework for a hierarchical classification system entailing an orgnized view of spatial and temporal variation among and within stream systems. Stream habitat systems, defined and classified on several spatiotemporal scales, are associated with watershed geomorphic features and events. Variables selected for classification define relative long-term capacities of systems, not simply short-term states. Streams and their watershed environments are classified within the context or a regional biogeoclimatic landscape classification. The framework is a prespective that should allow more systematic interpretation and description of watershed-stream relationships.