Riparian zone management in the Pacific Northwest: Who's cutting what?

In the Pacific Northwest (PNW) of North America, forestry practices during the last century have degraded the ecological linkages between riparian for ests and streams. In an attempt to protect the integrity of lotic ecosystem s and associated fisheries resources (primarily anadromous Pacific salmon, Oncorhynchus so.), regional governments now restrict timber harvest in ripa rian forests. I summarize and assess the riparian zone management guideline s of the states of California, Oregon, and Washington (USA) and the provinc e of British Columbia (Canada). Only Oregon and British Columbia protect fi sh-bearing streams with "no-harvest" zones, and only the wider (20-50 m) no -harvest zones for larger fish-bearing streams in British Columbia are like ly to maintain near-natural linkages between riparian and stream ecosystems . All four jurisdictions protect most streams with "management zones" of va riable width, in which timber harvest activities are restricted. All the ma nagement zone guidelines permit the harvest of the largest conifers from ri parian forests and will, if applied over a series of timber harvest rotatio ns (60-80 years), result in the continued removal of potential sources of l arge woody debris from the region's watersheds. All four jurisdictions requ ire additional protection for streams and watersheds that are severely degr aded or (in the United States) contain threatened or endangered species. Th e governments of the PNW have taken a "manage until degraded, then protect" approach to riparian forest management that is unlikely to maintain or res tore the full suite of riparian-stream linkages necessary for lotic ecosyst ems to function naturally at the stream, watershed, basin, or regional scal e.