Way of the Willow
John Senne had two problems. His land in Shannon County included Barren Fork Creek, a tributary to Sinking Creek. Heavy rains transformed this meandering creek into a river that carved soil from the banks and deposited large piles of gravel over Senne's road.
Following local advice, Senne tried to straighten the creek. People told him that this would eliminate the bends where the water was cutting into the soil and would speed up the movement of water and gravel past his low water access point. Senne described this advice in one word, "Wrong!" After several years of bulldozers and shovels, he admitted defeat and let the creek chose its own path.
Now a stream team member, Senne has a different philosophy. Part of helping nature along, he believes, means understanding the intricate connections between biotic and physical functions. Senne attended stream team and tree farming meetings to learn how land and trees on or near the banks of rivers and streams normally function. He needed trees. The streamside forest had been removed, and trees, shrubs and grasses were gone.
Armed with this new information, he allowed willows to naturally "spring-up" along the banks and planted other trees along the stream in a belt about 100 feet wide. Thirty years have passed and Senne feels he has done the right thing. Although he now has a concrete passage over the creek, gravel does not pile up like it did.
The volunteer willows and planted sycamores and other tree species help hold the stream bank in place. Yes, there is still some erosion, and occasionally a big tree falls into the river. However, when compared to the damage the creek was doing 30 years ago it seems insignificant.
Not only has Senne solved the problems of stream bank erosion and gravel deposition, his decision to restore a riparian forest helps nature provide cover and food for wildlife and clean water for stream life.
Lakes, rivers, streams and ground water supply the essential volumes we use for drinking, washing and cleaning. The water treatment plants we depend on to clean the water and make it safe for our consumption face a growing challenge. Cities generate magnitudes of polluted water. The city of Columbia even uses wetlands to help clean the water. And, in some rural places, soil and chemicals flow unchecked into our steams as a result of intensive grazing and row cropping.
The wetlands approach not only reduces the demand on water treatment plants, but provides critical wildlife habitat, too. It is an example of a win-win situation. Senne's solution works in rural areas. Planting rows of trees, shrubs and grasses along creeks and streams, landowners create buffer strips to help remove soil and chemicals from the water.
Historically, man cleared the fertile riparian areas and converted the land to fields or pasture. Intensive grazing and cultivation removed vegetation from the riparian area, thus removing the roots which held the soil in place. Degradation of soil and water quality resulted. The movement of sediment and stream bank erosion clouded the water and disrupted stream life. Surface runoff also transported chemicals to the streams and groundwater.
For minimal expense and care, riparian buffer strips can be maintained or constructed. Trees, shrubs and grasses maintain stream flow by absorbing excess water runoff, storing it, and releasing it at a later time. For example, riparian buffer strips reduce the severity of downstream flooding by slowing water.
In addition to holding stream bank soil in place during flooding, buffer strips also filter and spread water. Sediments and pollutants from fields are caught in the grasses, trees and shrubs before they enter the stream. And, according to recent studies, riparian buffer strips remove up to 80 percent of nitrogen and phosphorous from runoff and keep it from entering the stream. This reduces the threat of an algal bloom that would consume the oxygen needed by fish and other organisms in the stream.
Wildlife benefits too. The trees, shrubs and grasses provide habitat to a variety of birds and animals. Fish depend on riparian strips for cool water, aquatic vegetation, stream-bank shelters and a constant water supply. Conservation Department personnel periodically monitor Senne's stream. According to Senne, they are pleased with what they have found.
Trees, shrubs and grasses are the three elements of a riparian buffer strip. Depending on soil type and topography, land managers recommend a 60- to 100-foot wide strip along both sides of streams and rivers. Landowners can establish a riparian buffer strip in one of three ways. First, retain or restore native woodlands. Next, supplement native woodlands by planting additional rows of trees, shrubs, and grasses. Finally, plant new trees, shrubs and grasses along streams where little vegetation exists.
The riparian buffer strip should parallel the stream on both sides. To be effective, the Iowa State University Agroforestry Research Team recommends the following: starting at the stream, plant five rows of trees, two rows of shrubs and a band of grass 24 feet wide. Plant trees in a 4-foot by 6- to 8-foot spacing and shrubs in a 3-foot by 6- to 8-foot spacing.
This research team used willows, oaks, walnut, ash, and maple species in the tree rows. Shrub species included ninebark, chokecherry, and red osier dogwood, and switch grass was used for the grass strip. Other native shrubs, such as hazelnut, shrubby St. John's wort, and spicebush could be used.
Supplementing the switch grass with other warm season grasses, such as big bluestem, and Indian grass, is certainly appropriate. Some agencies provide cost-share programs to establish vegetation along streams and rivers and may have specific requirements for the number of trees per acre you plant. If necessary, the rows of shrubs can be eliminated and replaced by trees, but do not restrict the grass strip to less than 20 feet. Recent studies show that native warm season grasses, such as switch grass, big bluestem, and indian grass, provide more filtering and absorbing power than introduced, cool season pasture grasses.
The appropriate tree and shrub species to plant depend on the location, soil drainage and topography. Start with water loving tree species, such as willow, cottonwood, maple, poplar, green ash and box elder. These species grow fast and are adapted to a riparian habitat that is subjected to flooding.
If your soil is well drained, moderate-growth species could be planted. These species include river birch, hackberry, shellbark hickory, swamp white oak, pin oak, Ohio buckeye and sycamore. If you live in the Bootheel region of the state you might select cherrybark oak, bald cypress, Nuttall oak and swamp chestnut oak for the tree rows.
In the Bootheel Region shrub rows might include deciduous holly, spicebush and swamp privet, while big cane and other warm season grasses could be used for the grass strips. Landowners in the northern third of Missouri might pick different species. Trees such as white oak, bur oak, shellbark hickory and cottonwood are appropriate. Shrub and grass plantings would include hazelnut, aromatic sumac, shining sumac, side oats grama, little bluestem and switch grass. This is not a complete list.
Several other species would work fine. Planting different species will increase diversity and reduce the risk of losing all the plants to a pest, flood or drought. The trees and shrubs you decide to plant may also depend on whether you want primarily wildlife habitat, timber production or both. Take a look at what nature has planted around your riparian areas and use that as a guide. Your local forester can help you make the selection of trees, shrubs and grass to plant.
Riparian buffer strips cost around $400 per acre with $20 per acre for maintenance for the first 5 to 8 years (mowing, and weed control). However, you can recoup some of those costs. The wood could be ready for fiber products or firewood in 5 to 8 years, and timber products in 15 to 20 years.
Planting high-value hardwoods, such as walnut and oak, provide benefits for you and wildlife. Horticultural products, such as seeds and cuttings, can be grown for nurseries or the floral industry. The grass strips can be used for forage, if properly managed.
The greatest joy will be catching that smallmouth bass from a cool creek pool on a warm summer evening.
Streamside areas serve several functions in our ecosystem. They reduce floods and erosion, trap nutrients, store water and provide homes for wildlife. Beyond this, riparian areas are for people too. An abundance of cool shade and natural beauty provide a place for wildlife viewing, fishing and other water related activities. Riparian forests can be a special place for the family and visitors and are an indication of wise land management.