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WATERSHED RESTORATION The influence of rzstoring streamflo~v and halting grazing on Rush Creek, California, (1992-1996) is illustrated above. The small willow in the foreground in 1992 (left) is the same v:illow to the left of the third author in 1996. In 1992, a high density (50 m-~) of willow seedlings, \vas established on the gravel bar the first year v.~ithout livestock. By 1996, a dense willew communit~~ had formed, with many willows becoming more than 2 m in height. 199-1; Jackson et al. 1990. For example, the reintroduction of an extirpated fish species or the installation of log 1~'eirs and large boulders into a degraded stream reach does not constitute restoration. bti'hile attempts to rep-ive a single species are likely to target only a fe\,~ of its more obvious habitat requirements, less-apparent needs and important processes and functions are often ignored. hl the case of declining anadromous sahnonids, a technological perspec- tive has prevailed (Bottom 1997); first fish hatcheries, then fish ladders, and finally in-stream manipulations were looked on as solutions. Hol~~ev-er, increasingly apparent is that there is a remarkable complexity of enyironnlental phenomena that affect salmon yiability; and the cunnila- tiye losses of various biotic and physical components are vrhat must be addressed (\~ational Research Council 1996). By shifting the focus to the integrity of ecological process- es and functions, tee are more likely to successfully attain the restoration both of habitats and species of interest. Fcolo~ical restoration aLo should be distinguished from architechiral and mechanical ai_~;~~roaclles to ecosv-s- tenl nlana~~ement. such "re.c~raton" ~1)ztl~odolo~~ies often Cali for file systematic rea~hs:raction of a strearl accordin, :i) s~~c:C1S1~ htllmall DersLi~~C^:~.~~~~ ii, \\;Z~i i;le S`rean', "~hoUld OOk lli<°. More O::i11 Cllah. :':QC, CIIis \~ 111 not alllle.\'~' I11 ~~oal of ecological r~_°~tora.ih.~ n- st~ecies recov-erv. Mereiv re-creating a form v~ ithout ti-~.e function or the function in an artificial configuration does not constitute restoration (!\lational Research Council 1992). ~ long-term perspective regarding ecosystem sustainability is not inherent vv-ith these approaches. For example, the placement of artificial structures (boulders, rock gabions) does not replace many of the multiple functions of large, \~-oody debris, nor does it ensure or promote the future recruitment of ~,-oodv debris into the stream system. Such structures are commonly engineered and constructed vrith the false assumption that they and the stream channel are static. High tlou~s can be destructive v,-hen rigid structures are placed in degraded alluvial channels 113eschta et ~_?. 1991; Gregory and Bisson :~iu _.. undo ir. rll':'„ram ~ __,s a?pr~.~acl~: -gists in a lay;` disturbances, bedload transport, local scour and fill, lateral channel moyenlents, and particularly the interactions of streamside vegetation kith fluvial disturbance regimes. Fish hatcheries, fish ladders, and barging salmon do«'n- stream in damned rivers are artificial means of maintain- ing anadromous fish in systems (functions with no natural form). These approaches seldom address fundamental problems associated with restoring the habitats of natural fish runs. Such activities could be construed to be mitiga- tion or aquaculture but not restoration since they do noth- ing to restore habitat or rev-erne barriers to migration. Pl'['S~1"Z'!1 f1011 Preserzultion is the maintenance of intact ecosystems; it is distinct from ecological restoration, which only addresses degraded ecosystems. >=cosvstems that exist in a desired natural state vti~arrant preservation (\ational Research Coun- cil 1992, 1996). The protection and preservation of intact ecosystems are of great importance, both enyironnlentally and economically. P.estorin, the natural structure and func- tion of riparian and stream ecosv~-sums requires an under- Etdlldlllg OC the Co111~~1eX L~rOCeS~eS c.lld 1111k8~;e5 betDV'eell t11e b10 tIC alld pllV-'S1CaI COlnponell is of llltaCt Systems. lil- tact Ecosystems are necessary- as reference reaches from ~chich to compare the efficac.' r.f restoration programs (Case L9~; Beschta 1997). Furthermore, they are sources of natural genetic material for the reestablishment or reintroduction of the native biota to nearby areas in need of restoration. Preservation is a management strategy that entails more than simply preventing human-induced alterations. For example, management actions may be necessary to maintain natural functions and characteristics (e.g., prescribed fire, management of exotic species invasions, and large herbivore management). Measures to protect intact ecosystems (preser- vation) are important because they are often easier to imple- ment, have greater rates of success, and are less expensive than restoration. Preserving intact ecosystems also may be less expensive than restorin_- them, just as preventative I11~'dlCllle 15 neariV c.l.~.'~;;'~ .C~~ ~'\pE'^.Sll-2 'hall COrrE'CtlV'2 _'i~~ .. ., _ ~- ~ .._ ,- ~ .~rns 19931 T ''r ' .~~ ~rBCtal iss:; E' Ot' =r;'B ta_rsrle~ R~5tG ~~Ca ~'- ~151'terie5 f