Benefits of Streamside Forestry
The streamside forests of Kansas are some of the state’s greatest natural resources. Streamside forests (also known as riparian forests) play an important role statewide, as they act to protect water quality for more than 134,400 miles of streams, creeks, and rivers.
Across Kansas, streamside forests provide a wide range of benefits to both the environment, as well as landowners – benefits that include water quality and quantity enhancement, streambank protection, wildlife habitat, and enhanced recreational activities. These areas can also act as a sustainable source of income through timber harvest and the production of other forest products. Proper management of existing streamside forests, as well as establishment of new streamside forests are both critical to ensure high-quality water resources for generations of Kansans.
Impacts on Water Quality and Quantity
Forests along streams act to preserve and enhance water quality through a number of ways. Streamside forests act as filters, trapping pollutants found in surface runoff such as sediment, nutrients, pesticides, and bacteria, before these pollutants reach the state’s waterways. Deep root systems also act to absorb pollutants moving beneath the surface of the Earth, such as nitrate. Tree canopy cover along streams acts to shade and cool the water, maintaining healthy levels of dissolved oxygen that benefits many forms of aquatic life.
In addition to water quality, streamside forests play a significant role in the regulation of water quantity. Soils below streamside forests generally have a greater ability to absorb water than soils associated with other land-use types such as row-crop agriculture and urban. Because of this, forests allow precipitation to be absorbed and released slowly to the stream overtime, instead of running off the soil surface. This slow release reduces erratic, flashy flows that contribute to down-stream flooding. During flood events, tree trunks reduce the velocity of water, allowing more water to infiltrate into the soil and recharge groundwater.
Accounts from pioneers and Native Americans describe massive herds of bison congregating in large, river bottom stands of Cottonwoods and willows to ride out winter storms. The landscape looks much different today, but streamside forests still provide excellent habitat for a wide variety of terrestrial and aquatic wildlife. Because streamside forests are transitional zones between aquatic and upland ecosystems, they provide a unique mix of water, food, and cover. This transitional zone offers a wide range of micro-habitats and niches, and as a result, is utilized by a multitude of wildlife species.
Within the channel, tree roots and woody debris provide substrate and habitat for macroinvertebrates, fish, reptiles, and amphibians. Woody debris in the channel also aids in the creation of riffles, runs, and pools – stream structures important to fish. The forest canopy that overhangs the stream acts to regulate water temperatures, improving dissolved oxygen content or a variety of aquatic life.
Because of their linear nature, forests along streams produce more edge than upland forests – an important factor for many species, such as rabbits and quail. Large woody debris from the canopy creates den sites, and attracts insects and small mammals that act as prey for larger creatures like bobcat, snakes, and raptors. Snags, or standing dead trees, provide den and nesting sites for birds - and mammals such as raccoons, squirrels, and bats. Live riparian trees provide roosting sites for turkey, and bald eagles are occasionally spotted in large Bur oaks, Sycamores, and Cottonwoods lining river banks. Many types of waterfowl utilize riparian forests as well, such as Bufflehead, Wood duck, Goldeneye, and Mergansers.
Streamside forests are essential for streambank stability along many of the state’s waterways. In addition to smaller roots found mainly in the upper 8 inches of the soil, trees send larger roots into the ground vertically and laterally and use those roots as anchors to hold themselves in place. These larger roots help hold the soil, prevent bank failure, and reduce the amount of sediment washed downstream. Research at Kansas State University has shown that after the 1993 Kansas River flood, non-forested streambanks exhibited significantly more erosion than forested banks. Forested streambanks even showed an overall deposition of sediment during the flood. During high flow events, trees have the ability to slow the velocity of water, allowing sediment to settle out and accumulate in the forested areas. In addition to bank stability, trees also discourage flood debris from entering agricultural fields – a great benefit to landowners.
A direct result of healthy streamside forests, and streamside forest buffers, is an improved location for recreational activities ranging from hunting, camping, and wildlife watching - to swimming, boating, and fishing. Trees along streams also provide a unique form of aesthetics and beauty to the Kansas landscape.
Source of Sustainable Income
In addition to the array of environmental benefits provided by streamside forests, these areas can act as a sustainable source of income for landowners through timber and fuelwood harvest, nut production, and forest specialty products (such as berries and ornamentals).