Riparian Forests are one of the most ecologically diverse ecosystems in the world. Riparian is defined as a riverbank ecosystem that contains water dependant woody plants.

Riparian habitats, at the junction between wet and dry systems, are defined by the plants that they contain. The Kern River Watershed has one tree that ties all riparian systems together, the white alder (Alnus rhombifolia). Riparian plants depend on adequate groundwater and flowing natural surface water. On the Kern River all areas are subject to annual cycles of drought and flooding.

Rivers and Streams

Several regionally significant rivers, including the Kern River, Tule River, Kaweah River and Kings River, cut through the canyons and valleys of the southern Sierra Nevada. Continuous corridors of riparian vegetation cover hundreds of miles along Sequoia rivers, creeks and streams. In addition to forested riparian communities, there are riparian shrublands, marshlands, and grasslands. These plant communities are found at elevations from high wet meadows and seep wetlands, to tree-banked streams, to slack water sloughs and marshes in alpine, montane and floodplains.

Vegetation

Both forks of the Kern River consist of cottonwood/willow forest, which needs adequate spring runoff to replenish the aquifer and sustain the forest through summer and fall droughts.

Riparian areas in the higher elevations consist of aspen/alder forests. The quaking aspen is one of the most beautiful trees in the forest in fall. The shimmering leaves turn from a rich green to yellow and red before gently falling to the ground revealing a beautiful mottled gray bark.

Along many rivers and creeks from 1000 feet to over 10,000 feet, several broadleaf trees commonly form riparian gallery forests or woodlands. These communities are especially well-developed where environmental conditions permit a mix of some lower-elevation species with some higher-elevation species. Common native trees and shrubs, depending on location and elevation, include white alder (Alnus rhombifolia), big-leaf maple (Acer macrophyllum), Rocky Mountain maple (Acer glabrum), western dogwood (Cornus nuttallii), aspen (Populus tremuloides), box elder (Acer negundo), Oregon ash (Fraxinus latifolia), red bud (Cercis occidentalis), valley oak (Quercus lobata), California sycamore (Platanus racemosa), Fremont cottonwood, (Populus fremontii), narrowleaf cottonwood (Populus angustifolia), Scouler willow (Salix scouleriana), red willow (Salix laevigata) and arroyo willow (Salix lasiolepis).

Benefits

Riparian forests are crucial to the protection and enhancement of the water resources of the United States. They are extremely complex ecosystems that help provide optimum food and habitat for stream communities as well as being useful in mitigating or controlling nonpoint source pollution (NPS). Used as a component of an integrated management system including nutrient management and sediment and erosion control practices, streamside forests can produce a number of beneficial effects on the quality of water resources. Streamside forests can be effective in removing excess nutrients and sediment from surface runoff and shallow groundwater and in shading streams to optimize light and temperature conditions for aquatic plants and animals. Streamside forests also help correct some of the effects of pesticides, and directly provide dissolved and particulate organic food needed to maintain high biological productivity and diversity in the adjoining waterways.

Wildlife

Riparian forests support a greater diversity of wildlife than nearly all non-aquatic areas or upland forests. Forested riparian corridors function as connectors between isolated blocks of forested habitat. Riparian forests support high densities and diversities of migratory birds. Trees and shrubs are required for roosting or foraging by most riparian birds. In spring the South Fork Kern River Valley has some of the highest migration numbers in the entire southern Sierra Nevada. Each year in early May thousands of individual birds have been observed flying over this particular riparian forest. Most of these birds will continue north to their nesting grounds. Ninety-nine species of birds are known to nest in the South Fork Kern River forest.

Mammals depend on the vegetation for food and shelter. The increased humidity of riparian forests makes them important habitat for amphibians, snakes, and turtles. Snags are used as den sites and by cavity nesters. Root systems of woody vegetation not only help stabilize banks, but supply cover for fish and aquatic insects. Forest litter is the basis of food in the stream ecosystem, being utilized by insects that are in turn prey for fish.