FLOOD07093 - Laserfiche WebLink

Home Browse Search

transport by reducing flow velocities and causing deposition. Since the primary source of sediment in many streams is bank erosion (Dunne and Leopold 1978), sediment load can be significantly limited by bank vegetation. In agricultural watersheds with significant sediment laden runoff, riparian vegetation traps sediments before they reach the stream (Lowrance et al.. 1984). Nutrient tmpping and removal. Riparian vegetation traps both suspended and dissolved materials and contributes significantly to the high fertility of floodplain soils. Suspended particles in overbank flow and upland runoff are depllsited when flow velocities are decreased by vegetation. Most notably, carbon, nitrogen, and phosphorous concentrations in surface water are effectively reduced by floodway vegetation (Peterjohn and Correll 1984). Additionally, riparian root systems uptake dissolved nutrients in subsurface water. Wildlife habitat. Riparian habitats provide breeding sites, wintering areas, and migratory stop-over areas for numerous wildlife species. The provision of food, cover, and shelter has long been an important, widely recognized function of riparian vegetation (Brinson et al. 1981, Minshall et al. 1989). This is especially true in the central and western United States where riparian woodlands provide uncommon and structurally complex habitats relative to the surrounding grassland or shrubland. Lowland riparililn forests occupy only 3% of Colorado's land area but contain the highest bird species richness and abundance than any other ecosystem in the state except for marshes (Kingery 1998). The IArkansas River below John Martin Dam harbors a nationally prominent white-tailed deer pop\.ilation (Ed Gorman, Habitat Biologist, Colorado Division of Wildlife, October 1998, pers. qomm.). Individual deer are known to range throughout 350 to 400 acres of riparian woodland d~ring the course of the year (Kufeld and Bowden 1995). Riparian plant communities serve as travel corridors for local populations of deer and other mammals, and as major migration routes for migratory birds. Importance to aquatic systems. Bank vegetation also is an important component of aquatic faunal habitat (Platts 1983). Streamside vegiltation provides shade and cover for fishes where it overhangs the water surface. The contribution of carbon to downstream aquatic habitats is one of the most widely recognized functions of riparian vegetation (Brinson et al. 1981). 3.3.4 Special Status Species For future planning along the Arkansas River, Federal and State agencies and their current special status species lists must be consulted for all listed floral and faunal species. Federal and/or State species of concern should also be considered although they, at this time, are not afforded legal protection. The Federal and/or State special status species that are "listed," meaning designated as Endangered, Threatened, those proposed for listing as Endangered or Threatened, or species that are a Candidate for listing must be considered. Special status species that are known to occur or that have the potential to occur along or near to the Arkansas River currently include: showy prairie gentian, Colorado green gentian, Arkansas Valley evening primrose, black-footed ferret, Swift/Kit fox, black-tailed prairie dog, Bald Eagle, Interior Least Tern, Piping Plover, Western Snowy Plover, Mountain Plover, Long-billed Curlew, Whooping Crane, Greater Sandhill Crane, White Pelican, Less~r Prairie Chicken, Loggerhead Shrike, Western Burrowing Owl, Ferruginous Hawk, suchelmouth minnow, Arkansas darter, plains 42 I I I I I I I I I I I I I I I I I I I