CHANNEL FORM AND STREAM ECOSYSTEM MODELS¹

Abstract

A system is proposed to classify running water habitats based on their channel form which can be considered in three different sedimentological settings: a cobble and boulder bed channel, a gravel bed channel, or a sand bed channel. Three physical factors (relief, lithology, and runoff) are selected as state factors that control all other interacting parameters associated with channel form. When these factors are integrated across the conterminous United States, seven distinct stream regions are evident, each representing a most probable succession of channel forms downstream from the headwaters to the mouth. Coupling these different channel profiles with typical biotic community structures usually associated with each of the channel types should result in considerable refinement of the applicability of the River Continuum Concept and other holistic ecosystem models by realizing the nonrandomness of the effects of geomorphology on stream ecosystems. Thus, this regional perspective of streams should serve to make persons concerned with water resources more aware of the geographical considerations that affect their study areas. (KEY TERMS: alluvial; channel form; fluvial geomorphology; stream ecosystems.)

Leaf-litter stoichiometry is affected by streamwater phosphorus concentrations and litter type

“…Mean stream width and depth were 7.5 m (2.0-23.3 m) and 0.26 m (0.04-1.50m), respectively. Stream substrata were primarily gravel, and streams had riffle-pool channel morphology (Brussock et al 1985). Preliminary data suggested that these streams represented a gradient in total P (TP) concentration.…”

Landscape heterogeneity and the biodiversity of Arctic stream communities: a habitat template analysis

“…Patterns of periphyton and macroinvertebrate community structure show similar variation, within and among streams, because their distribution is greatly influenced by habitat structure (Brussock et al 1985;Huryn and Wallace 1987;Lowe and Pan 1996). As a consequence, the habitat-template approach (Southwood 1988) has been effective in predicting patterns of spatial and temporal variability in stream community structure (Scarsbrook and Townsend 1993;Townsend et al 1997a;Biggs et al 1998).…”

Nutrient Retention, Nutrient Limitation, and Sediment-Nutrient Interactions in a Pasture-Dominated Stream

“…Moore's Creek is a spring-fed second-order stream that is a part of the Illinois River basin in northwest Arkansas. The headwater streams of the Illinois River basin have alluvial gravel, riffle-pool geomorphology (Brussock et al, 1985). Streams substrates in this river basin are dominated by limestone, sandstone, and shales and have a karst topography.…”