Riparian habitats are those adjacent to rivers and streams or occurring on nearby floodplains and terraces. Riparian habitats are shaped and maintained through seasonal flooding, scour, and soil deposition. Floods replenish nutrients, recharge groundwater, and reset successional processes. Riparian habitats occur along rivers and streams at all elevations, from valley bottom floodplains to alpine torrents. Riparian habitats also include springs, seeps, and intermittent streams, and many low elevation alluvial floodplains confined by valleys and inlet.
Riparian habitats vary from sparsely vegetated areas to cottonwood gallery forests due to flood dynamics. Plant composition is influenced by elevation, stream gradient, floodplain width, and flooding events. Throughout most of the state, riparian vegetation is mostly dominated by deciduous trees and shrubs, such as bigleaf maple, alders, aspen, cottonwood, dogwood, willows and Oregon white ash. Conifers, such as pines and spruce, dominate some riparian woodlands at higher elevations. Riparian habitats in the Blue Mountains ecoregion are the most variable in Oregon, influenced by elevation and precipitation. In some ecoregions, riparian habitats include some riparian shrublands. In the East Cascades, riparian shrublands are dominated by deciduous shrubs, such as willows, creek dogwood, western birch or hawthorn. Shrub thickets in the Northern Basin are dominated by deciduous shrubs, such as several species of willow, birch, alder, and chokecherry. Riparian meadows are also found in the Northern Basin and Range and are dominated by grasses, sedges and rushes.
For more information on the Strategy Habitat: Riparian Habitats, please see the Oregon Conservation Strategy (PDF file; 2.37 MB)
Excerpted with permission from Oregon Department of Fish and Wildlife. 2006. Oregon Conservation Strategy. Oregon Department of Fish and Wildlife, Salem, Oregon.