Riparian Zone Associations: Deschutes, Ochoco, Fremont, and Winema National Forests

摘要

Riparian zones (ecosystems) occur along the interface between aquatic and terrestrial ecosystems. These water oriented ecosystems are well defined and are surrounded by much drier upslope ecosystems. They make up a minor portion of the landscape but are extremely important in regard to land management and land use. The riparian zone is composed of two distinct ecosystems: This classification supplements and expands the riparian information presented in plant association guides by Hall (1973), Volland (1976), Hopkins (1979a and b), and Hopkins and Kovalchik (1983) . Aquatic ecosystems are not included in the classification. Intermittent streams, dry draws, and other land features that may at times transport water but do not support riparian zone vegetation are not included in the classification. The riparian ecosystem is that land, next to water, where plants that are dependent on a perpetual source of water occur. Riparian sites include fluvial surfaces such as streambanks, active channel shelves, active floodplains, and overflow channels. The transitional ecosystem occurs on subirrigated sites that lie between the riparian and upland. It does not have true riparian vegetation such as sedges and willows yet is uniquely different from uplands. Transition sites include inactive floodplains, terraces, toe-slopes, and meadows which have seasonably high water that recedes to below the rooting zone in mid to late summer. Until recently, the structural, compositional and functional components of riparian zones received little consideration in ecosystem research, management, and planning (Youngblood and others 1985a). Current Forest Service policy calls for riparian resource management concentrating on the importance and unique values of the system, as well as the classification, inventory, and delineation of riparian ecosystems for land management planning (McGuire 1979).