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Riparian Forest Buffers

Riparian forest buffers are areas of trees, shrubs, and other vegetation found next to stream channels and other waterways.They are modeled on natural communities such as bottomland hardwood forest, coastal scrub, and upland oak-hickory-pine forests. Conversion of these riparian forests to other land uses has contributed to ecological problems in our waterways and the Chesapeake Bay including sedimentation, nutrient and toxic chemical pollution, and reduction of fish habitat.

Riparian wetlands are characterized by plant species adapted to periodic flooding and/or saturated soils. They support a high diversity of plant and animal species. More energy and materials, born by moving water, enter, are deposited in, and pass through riparian ecosystems than any other wetland ecosystem. Drier upland forests adjacent to waterways also provide many of the same ecosystem values.

Riparian forest buffers help control the rate and volume of water flowing in streams and rivers, greatly influencing flood levels. Water flowing through a riparian forest is slowed by the vegetation, leaf litter, and porous soils found there.

The leaf litter acts as a filtration system by capturing sediment from upland runoff. This action also helps to filter out phosphorous bonded to sediment particles. Sediments, and any nutrient which may be bonded to them, become part of the forest soil rather than clouding our waterways.

Chemical and biological processes of the forest remove nutrients, such as phosphorous and nitrogen, and store them in the soil or as plant tissue. Pesticides are also converted to nontoxic compounds by various chemical and microbial activities within the forest. This helps to protect fish, which are most threatened by pesticide pollution.

Riparian forest soils act as areas of water storage. Plants take up water into their tissues and release it into the atmosphere.

A canopy created by riparian forest provides shade and controls water temperature, which is essential for instream organisms, including trout and the invertebrate food source on which they depend. Instream, the leaf litter and woody debris from the canopy and forest create food and habitat vital to the aquatic food web.

Riparian forests provide food and habitat for a variety of terrestrial wildlife and serve as safe corridors for movement between habitats. Habitat conversion and fragmentation have reduced wildlife habitat and limited the ability of animals to move between existing habitats. Riparian forests provide for both these needs.

Riparian forest buffers offer recreation to fishermen, birders, hikers, canoeists, and picnickers. The diversity of habitats and life and the scenic beauty provided by riparian forests can be enjoyed by many people in so many different ways.

These ecological functions combine to make riparian forest buffers critical investments in human and ecological health and well-being today, and for our children tomorrow. Recognizing these values, the Chesapeake Bay Program has set a goal of replanting 2,010 miles of Bay shoreline by the year 2010. Virginia's share of this goal is 610 miles.

RIPARIAN VEGETATION ZONES

Four riparian vegetation zones are identified in this brochure. Zone 1, the emergent vegetation zone, is permanently to semipermanently flooded and often dominated by grasses, sedges, rushes, and herbaceous plants. Zone 2, the riverside thicket, may be seasonally to temporarily flooded and is often characterized by emergent species, shrubs, and a few tree species. Zone 3, the saturated forest, has soils which are saturated to poorly drained. Zone 4, the well-drained forest, is also known as upland forest. Zones 3 and 4 are dominated by trees, but also contain shrub and herb layers in the understory.