Riparian buffer - AbsoluteAstronomy.com

A riparian buffer is a vegetated area (a "buffer strip

Buffer strip

A buffer strip is an area of land maintained in permanent vegetation that helps to control air, soil, and water quality, along with other environmental problems, dealing primarily on land that is used in agriculture. Buffer strips trap sediment, and enhance filtration of nutrients and pesticides by...

") near a stream

Stream

A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...

, usually forest

Forest

A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

ed, which helps shade and partially protect a stream from the impact of adjacent land use

Land use

Land use is the human use of land. Land use involves the management and modification of natural environment or wilderness into built environment such as fields, pastures, and settlements. It has also been defined as "the arrangements, activities and inputs people undertake in a certain land cover...

s. It plays a key role in increasing water quality

Water quality

Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...

in associated streams, river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s, and lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s, thus providing environmental benefits. With the decline of many aquatic ecosystems due to agricultural production, riparian buffers have become a very common conservation

Conservation ethic

Conservation is an ethic of resource use, allocation, and protection. Its primary focus is upon maintaining the health of the natural world: its, fisheries, habitats, and biological diversity. Secondary focus is on materials conservation and energy conservation, which are seen as important to...

practice aimed at increasing water quality and reducing pollution

Water pollution

Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....

Benefits

Riparian buffers act to intercept sediment

Sediment

Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

, nutrient

Nutrient

A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...

s, pesticide

Pesticide

Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...

s, and other materials in surface runoff

Surface runoff

Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...

and reduce nutrients and other pollutants in shallow subsurface water flow. They also serve to provide habitat

Habitat

* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

and wildlife corridor

Wildlife corridor

A wildlife corridor or green corridor is an area of habitat connecting wildlife populations separated by human activities . This allows an exchange of individuals between populations, which may help prevent the negative effects of inbreeding and reduced genetic diversity that often occur within...

s in primarily agricultural areas. They can also be key in reducing erosion

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

by providing stream bank stabilization.

Water quality benefits

Intercepting sediments/nutrients - Key to counteract eutrophication
Eutrophication
Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...

in downstream lakes and ponds which can be detrimental to aquatic habitats because of large fish kill
Fish kill
The term fish kill, known also as fish die-off and as fish mortality, is a localized die-off of fish populations which may also be associated with more generalised mortality of aquatic life...

s that occur upon large-scale eutrophication.
Intercepting pesticides - Riparian buffers keep chemicals that can be harmful to aquatic life out of the water. Some pesticides can be especially harmful if they bioaccumulate in the organism, with the chemicals reaching harmful levels once they are ready for human consumption.
Bank stabilization - This is important because erosion can be a major problem in agricultural regions when cut (eroded) banks can take land out of production. Erosion can also lead to sedimentation
Sedimentation
Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained, and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration...

and siltation
Siltation
Siltation is the pollution of water by fine particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments, and to the increased accumulation of fine sediments on bottoms where they are undesirable...

of downstream lakes, ponds, and reservoirs. Siltation can greatly reduce the life span of reservoir
Reservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

s and the dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

s that create the reservoirs.

Habitat benefits

Provide habitat - Riparian buffers can act as crucial habitat for a large number of species, especially those who have lost habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

due to agricultural land being put into production.
Increase biodiversity - By adding this vegetated area of land near a water source it becomes a prime location for species that may have left the area due to non-conservation land use to re-establish. With this re-establishment the number of native species and biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

in general can be increased.
Buffers acting as corridors - Buffers also serve a major role in wildlife habitat. The habitat provided by the buffers also double as corridors for species that have had their habitat fragmented by various land uses.
Shading water - The large tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

s in the first zone of the riparian buffer provide shade and therefore cooling for the water, increasing productivity and increasing habitat quality for aquatic species.

Economic benefits

Increase land value - Often people who purchase land for recreational use are willing to pay more if there is more wooded area located on the land.
Produce profitable alternative crops - Vegetation such as Black Walnut
Black Walnut
Juglans nigra, the Eastern Black walnut, is a species of flowering tree in the hickory family, Juglandaceae, that is native to eastern North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida and southwest to central...

and Hazelnut
Hazelnut
A hazelnut is the nut of the hazel and is also known as a cob nut or filbert nut according to species. A cob is roughly spherical to oval, about 15–25 mm long and 10–15 mm in diameter, with an outer fibrous husk surrounding a smooth shell. A filbert is more elongated, being about twice...

, which can be profitably harvested, can be incorporated into the riparian buffer.
Increase lease fees for hunting - The increased habitat means that the land will be more sought-after for hunting purposes.

Buffer design

A riparian buffer is usually split into three different zones, each having its own specific purpose for filtering runoff and interacting with the adjacent aquatic system. Buffer design is a key element in the effectiveness of the buffer. It is generally recommended that native species be chosen to plant in these three zones, with the general width of the buffer being 50 feet (15.2 m) on each side of the stream.

Zone 1. This zone should function mainly to shade the water source and act as a bank stabilizer. The zone should include large native tree species that grow fast and can quickly act to perform these tasks. Although this is usually the smallest of the three zones and absorbs the fewest contaminants, most of the contaminants have been eliminated by Zone 2 and Zone 3.

Zone 2. Usually made up of native shrubs, this zone provides wonderful habitat for wildlife, including nesting areas for bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

species. This zone also acts to slow and absorb contaminants that Zone 3 has missed. The zone is an important transition between grassland and forest.

Zone 3. This zone is important as the first line of defense against contaminants. It consists mostly of native grass

Grass

Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...

es and serves primarily to slow water runoff and begin to absorb contaminants before they reach the other zones. Although these grass strips should be one of the widest zones, they are also the easiest to install.

Streambed Zone. The streambed zone of the riparian area is linked closely to Zone 1. Zone 1 provides fallen limbs, trees, and tree roots that in turn slow water flow, reducing erosional processes associated with increased water flow and flooding. This woody debris also increases habitat and cover for various aquatic species

Species selection (example using native Nebraska species)

In Zone 1: Cottonwood, Bur Oak, Hackberry, Swamp White Oak, Siberian Elm, Honeylocust, Silver Maple, Black Walnut, Northern Red Oak, and Russian Olive.

In Zone 2: Manchurian Apricot, Silver Buffaloberry, Caragana, Black Cherry, Chokecherry, Sandcherry, Peking Cotoneaster, Midwest Crabapple, Golden Currant, Elderberry, Winter Euonymus, Washington Hawthorn, American Hazel, Amur Honeysuckle, Common Lilac, Amur Maple, American Plum, and Skunkbush Sumac.

In Zone 3: Western Wheatgrass, Big Bluestem, Sand Bluestem, Sideoats Grama, Blue Grama, Hairy Grama, Buffalo Grass, Sand Lovegrass, Switchgrass, Little Bluestem, Indiangrass, Prairie Cordgrass, Prairie Dropseed, Tall Dropseed, Needleandthread, Green Needlegrass.

Managing forests in riparian area

Logging

Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...

is sometimes recommended as a management practice in riparian buffers, usually to provide economic incentive. However, some studies have shown that logging can harm wildlife populations, especially birds. A study by the University of Minnesota found that there was a correlation between the harvesting of timber in riparian buffers and a decline in bird populations. Therefore, logging is generally discouraged as an environmental practice, and left to be done in designated logging areas.

Conservation incentives

The Conservation Reserve Program

Conservation Reserve Program

The Conservation Reserve Program is a cost-share and rental payment program under the United States Department of Agriculture , and is administered by the USDA Farm Service Agency . Technical assistance for CRP is provided by the USDA Forest Service and the USDA Natural Resources Conservation...

(CRP), a farming assistance program in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, provides many incentives to landowners to encourage them to install riparian buffers around water systems that have a high chance of non-point water pollution and are highly erodible. For example, the Nebraska

Nebraska

Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....

system of Riparian Buffer Payments offers the following:

Annual rental payments = $62 to $116 per acre/year (up to $96 per acre per year for certain marginal pasture land)
Sign up bonus: up-front payment of $10 per acre/year for the life of the contract (Example: $150/ac for a fifteen year contract)
Payments for 90% of costs for trees, shrubs, grass seed, site preparation and planting
10 to 15 year contracts
Eligible areas:
- Up to 180 feet (54.9 m) average width along each side of a continuous or intermittent stream
- Strips of grass, shrubs, and/or trees can be used
- Planting done by the local Natural Resource Districts (NRDs)

These incentives are offered to agriculturists to compensate them for their economic loss of taking this land out of production. If the land is highly erodible and produces little economic gain, it can sometimes be more economic to take advantage of these CRP programs.

Effectiveness

Riparian buffers have undergone much scrutiny about their effectiveness, resulting in thorough testing and monitoring. A study done by the University of Georgia

University of Georgia

The University of Georgia is a public research university located in Athens, Georgia, United States. Founded in 1785, it is the oldest and largest of the state's institutions of higher learning and is one of multiple schools to claim the title of the oldest public university in the United States...

, conducted over a nine-year period, monitored the amounts of fertilizers that reached the watershed from the source of the application. It found that these buffers removed at least 60% of the nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

in the runoff, and at least 65% of the phosphorus

Phosphorus

Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...

from the fertilizer application. The same study showed that the effectiveness of the Zone 3 was much greater than that of both Zone 1 and 2 at removing contaminants.

Long-term sustainability

After the initial installation of the riparian buffer, relatively little maintenance needs to be performed to keep the buffer in good condition. Once the trees and grasses reach maturity, they regenerate naturally and make a more effective buffer. The sustainability of the riparian buffer makes it extremely attractive to landowners, since they do relatively little work and still receive payments. Riparian buffers have the potential to be the most effective ways to protect aquatic biodiversity, water quality and manage water resources in developing countries that lack the funds to install water treatment and supply systems in midsize and small towns.