Riparian communities associated with Pacific Northwest headwater streams: assemblages, processes, and uniqueness

• Published in: Journal of the American Water Resources Association Vol. 41; no. 4; pp. 935 - 947
• Main Authors: Richardson, J.S, Naiman, R.J, Swanson, F.J, Hibbs, D.E
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Middleburg, VA American Water Resources Association 01.08.2005
• Subjects: animal ecology; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; floodplains; Freshwater; habitat management for wildlife; Hydrology; Hydrology. Hydrogeology; land use; literature reviews; montane forests; plant ecology; Pollution, environment geology; riparian areas; riparian forests; silvicultural practices; streams; wildlife habitats; Pacific States; INE, USA, Pacific Northwest; USA, Pacific Northwest; forest; habitat; vegetation; species diversity; North America; riparian ecology; nutrients; ecology; water resources; floodplain; plants; organic carbon; wildlife; rivers; streams; channel geometry; forests; heterogeneity; floodplains; rivers/ streams; water resource management; organic materials; riparian environment; sediments; communities
• ISSN: 1093-474X; 1752-1688
• DOI: 10.1111/j.1752-1688.2005.tb04471.x

Riparian areas of large streams provide important habitat to many species and control many instream processes - but is the same true for the margins of small streams? This review considers riparian areas alongside small streams in forested, mountainous areas of the Pacific Northwest and asks if there are fundamental ecological differences from larger streams and from other regions and if there are consequences for management from any differences. In the moist forests along many small streams of the Pacific Northwest, the contrast between the streamside and upslope forest is not as strong as that found in drier regions. Small streams typically lack floodplains, and the riparian area is often constrained by the hillslope. Nevertheless, riparian-associated organisms, some unique to headwater areas, are found along small streams. Disturbance of hillslopes and stream channels and microclimatic effects of streams on the riparian area provide great heterogeneity in processes and diversity of habitats. The tight coupling of the terrestrial riparian area with the aquatic system results from the closed canopy and high edge-to-area ratio for small streams. Riparian areas of the temperate, conifer dominated forests of the Pacific Northwest provide a unique environment. Forest management guidelines for small streams vary widely, and there has been little evaluation of the local or downstream consequences of forest practices along small streams.