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sizes, and spatial distributions of wood both in and along stream channels. During the inevitable high-water events that follow, added wood should function effectively in channel development and sediment and hydrologic rout- ing (Gregory and Bisson 1997). Managers should place logs in or along channels so they resemble natural accu- mulations of debris, and should use complex wood debris (e.g., whole trees with branches and root wads if at all possible) to maximize habitat values and minimize poten- tial for movement. The placement should enhance condi- tions that facilitate natural establishment of woody species (e.g., point-bar formation or nurse logs) so wood recruit- ment will become aself-perpetuating process. Anchoring or cabling complex pieces should be done sparingly, if at all, because it does not allow for the natural behavior of log accumulations during high-flow events. In this respect log length is critical; logs longer than the active channel width are not likely to move very far downstream (Lien- kaemper and Swanson 1956). Unfortunately, structural additions to channels (e.g., logs, boulders) are too often undertaken before anthropo- genic impacts causing degradation have been eliminated or before significant natural recovery of riparian plant communities has occurred. In both situations, artificial struch-ral additions are premature and can cause addition- al degradation to riparian and agttatic ecosystems. Of par- ticular importance is the concern that placement activities should not diminish the natural regrowth capacity of riparian forests and should not severely curtail or acceler- ate natural channel dynamics such as channel migration, pool development, and streambank building. Riparian and stream ecosystems degraded from off-channel activities cannot be restored by focusing only on manipulations within a channel. Throughout the western United States, inchannel place- ment of habitat structures has become one of the most common and widespread stream "enhancement" activi- ties. Although instream structures have been commonly used in attempts to control channel erosion and rehabili- tate fish habitat since the early twentieth century (Elmore and Kauffman 1990, systematic eyahtation of their success has been limited. Furthermore, instream habitat hand- boo!s (e.g., U.S. Forest Service 193?; Seehorn 1953, 199? ~ etizrally provide no ecolo~ical_ or geomorphic perspecri-,-e as to ~~•here various habitat manipulations are appropriate (Or mapproprlate). i~ SL1ITlI'_1nr}" Or 1nStleam enhanCemel?: projects throughout the region (Beschta et al. 1990 indiaa- ed little or no positive fisheries response to stntctural approaches. Clearly; the widespread practice of engineered structural modifications to streams with little or no scien- tific evidence of biological benefits represents a manage- ment paradox of immense proportions. Misinterpretation of Ecosystem Needs Active restoration should be undertaken to facilitate recoe•erv of nahral ecosystem processes (Kauffman et al. ] 993). Riparian and instream activities that do not address ecosystem function and linkages are likely to fail or even WATERSHED RESTORATION exacerbate degradation of the ecosystem-a result of mis- interpretation of ecosystem needs. Examples of such mis- interpretation might include outplanting hatchery fish of nonindigenous genetic strains and introducing nonnative plant species. Implementation of riparian or inchannel activities that further degrade or prevent reestablishment of hydrologic, geomorphic, or biotic functions also repre- sents amisinterpretation of ecosystem needs (Figure 3). Such activities may involve habitat manipulations such as blasting bedrock channels; adding logs and boulders in Ecological restoration is a holistic approach not achieved through isolated manipulations of individual elements but through approaches ensuring that natural ecological processes occur.::. channels formed in floodplains of finely textured meado~y systems; implementing in-channel engineering approaches that are heavily anchored by cable, metal rods, or boulders (structures that rely on geotextile fabrics to maintain their integrity); armoring streambanks with large boulders; and placing excavated sediments on streambanks and flood- plains. Many of these approaches not only severely limit the capacity for streams to undergo natural adjustments in channel morphology- and stream sinuosity through time, but they also ma~• create conditions that suppress or stop the recovery of riparian vegetation. Unfortunately, misinterpretating ecosystem needs is common ~~~ith many instream rehabilitation and enhance- ment programs (Beschta et al. 1991; Kauffman et al. 1993). Stream manipulations targeted to fish habitat enhance- ment often exacerbate riparian and stream degradation for many reasons (Beschta et al. 1990: • • An inadequate understanding of riparian and stream ecology; partictaarly hotr stream-side vegetation and disturbance patterns shave both channels and habi- tat features; • Sociopolitical pressure; ~ ~.,., it is socially or politi- ali;~ unacceptable to cI?an,e ongoing land use pr._- L1C.~ tila: are CaLaln' dc''=raiatlOn); ?_._:inltional li^~=a_":•,_ re_ar:ii ,~ the use of ayail- abie funLis le.<_., appropriations are designated onl_.~ COr n?eClianiCai CSC ei1~lnC~iin} a~ pr01C1leS t0 Strec~^~ manipulation n•ith little or no appreciation of -the effectiveness of impro~~ed stewardship); • Management philosophies that emphasize immediately quantifiable project results (e.g., the number of instream stntctures built during a fiscal year) rather than eco- logical improvement or improved stewardship; • Emphasis on a "landscaping" approach (e.g., design- in~ channels or buildin, structures based on precon- ceived plans rather than addressing factors limiting the processes that creatz these habitat feahires); • A presumption that engineering approaches (e.g., placement of boulders, ~rood~." debris, gabions, P;1av 199' Special Issue o~, ~':?'e~n~~' Restora'~or Fisherizs ~~ -. ,