an ir./'ospitaole environn.ent for benthic macroinvertebrates , since few local orga- ^ 

 nisms are adepted for a "freshwater intertidal" life (Hanson and Eberhardt 1971:3- f 

 9, Payne, et al . 1976). Stranding of benthic insects on a wide littoral zone can 

 be lethal during exposure periods of 24-28 hours; Ephemeroptara, a key food source 

 of the dipper (Mithcell 1968), are especially intolerant to short-term exposure 

 (&>^usven et al . 1974). A stabilized river shoreline would probaoly be more pro- 

 ductive of aquatic insects than the present fluctuating' shoreline, although species 

 composition would change drastically; net effects on availability of suitable food 

 for waterfowl broods are uncertain. Shoreline stabilization could also result in 

 increased production of rooted aquatic vegetation, which is important to divin^^ 

 ducks, once siltation establishes suitable substrate (McKern 197G). Shore- 



line stabilization and eventual siltation cou^d increase breeding and estivation 

 habitat for riparian amphibians such as the leopa-^d frog ( Rana pipiens ) and spotted 

 frog (Rana pretiosa ) , both of which were consipicuously absent from both the Kootenai 

 Falls study area and from the widely fluctuating Columbia River (McKern 1976). 

 Creation of a muddy-bottomed r^verbank via sedimentation could create habitat for 

 mud-probing shorebirds, which were also conspicuously rare in tlie Kootenai and 

 Columbia River study areas (Payne et al . , 1976). Stabilization of shoreline eleva- 

 tions could also benefit furbearers by preventing the exposure of dens with young 

 to drowning (due to sudden high discharges) or predation (due to exposure of den 

 entrances at low water), and possibly increasing food supply (faber and Raedeke 

 1976; Martin 1977). 



Terrestrial (Supra! ittoral ) Habitats . At a river discharge of KOO cms (50,000 

 cfs), the project as proposed (forebay at 610 m (2,000 ft) would inundate roughly 

 24.5 ha (60.6 acres) of riparian habitats which would otherwise be exposed. An ad- 

 ditional 4.6 ha (11.4 acres) of land would be disturbed for railroad relocation, ^k 

 bringing the total amount of riparian habitat which would be altered at the project^^ 

 site to roughly 29.1 ha (72 acres) (table 21). An unknown amount of additional habi- 

 tat would be disturbed off-site to provide housing for construction workers and to 

 produce the fuel and materials necessary for construction of the project. This loss 

 of habitat represents a reduction in carrying capacity for all species presently de- 

 pendent upon the affected terrestrial habitats (see pages for a list of spe- 

 cies for the individual habitats listed in table 21). 



Of the 29.1 ha (72 acres) of habitat affected, 9.8 ha (24.3 acres) (34%) are 

 dominated by trees and/or shurbs (including the willow, birch-alder-dogwood, ripar- 

 ian Cottonwood, cottonwood-conifer, and conifer-dominated types). Trees and/or 

 shrubs dominate 6.8 ha (16.8 acres) (28%) of the 24.5 ha (60.6 acres) which would 

 be inudated at a forebay elevation of 610 m (2,000 ft), and 3.0 ha (75 acres) (66%) 

 of the 4.6 ha (11.4 acres) which would be disturbed by railroad relocation. Most 

 of this latter area would represent a permanent, long-term loss since the new rail- 

 road right-of-way would be kept clear of trees and tall shrubs. Loss of riparian 

 trees and shrubs is especially significant, since these riparian habitats are not 

 only highly diverse and productive, but also increasingly rare. 



Due to various human developments, riparian vegetation has been reduced in 

 the United States to 70 - 90 percent of its original extent, and remaining riparian 

 habitat continues to be destroyed at approximately 5 percent per year (McCormick 

 1968). Realizing the value of this diminishing resource, the U.S. Forest Service 

 recently conducted two national symposia dealing witli the importance, protection. 



88 



