What is a Riparian Buffer? Why do they matter?
The riparian area is the land alongside a stream or river that directly affects—or is affected by — the water. A riparian buffer is a green corridor along a river or stream that separates the water from surrounding land uses. Healthy riparian buffers contain trees, shrubs, and other vegetation that protect both the stream and streamside property. In our local watersheds, as in many places throughout the world, many of our riparian buffers have been cleared in order to make additional space for lawns, houses, fields and roads.
What happens each day in a Riparian Buffer?
Nightime often brings rain and condensation settling over the landscape. In a natural vegetated buffer that water slowly sinks into the ground, whereas on a parking lot or lawn the water would collect and run right off the compacted surface.
As the morning comes and the sun shines on the wetted plants some of the water evaporates off, but in a vegetated buffer zone the native plants and trees shield that water from the sun, keeping the stream and ground around them cooler. As hotter weather arrives earlier in the year and stays later through the fall these shaded areas are important infrastructure to keep streams from overheating and "cooking" the aquatic life that depends on them.
Throughout the afternoon, wildlife will run, fly and swim throughout the habitat these buffer areas provide. Riparian buffers provide food and water to birds, mammals, fish, reptiles, and important insects like pollinators.
As nightime settles again a storm may appear, lashing high water flows against the banks of the streams. The roots of native trees and shrubs are particularly adapted to hold soil and prevent erosion, and prevent your land from being washed downstream.
What happens without a Riparian Buffer?
The lack of healthy riparian buffers has contributed to stream bank instability and erosion, diminished water quality, and habitat degradation. Too often landowners believe that a mowed lawn is a healthy natural area - but lawns don't provide habitat, shade streams, and their roots are too short to prevent erosion. Lawns are often so compacted that water can't soak in - to the point that they've been nicknamed "green concrete" for their lack of natural functions.
Properly maintained riparian buffers stabilize stream banks, decrease high storm flows, filter nutrients and sediment from stormwater, provide essential habitat for fish, birds, and other wildlife, and increase property values. Generally, the wider the buffer, the more effective it will be. At a minimum, a streamside buffer should extend to the top of the streambank slope. A healthy riparian buffer protects your property from the stream, and the stream from you.
So how do I go about establishing a healthy Riparian Buffer?
1. Stop mowing next to the stream.
Generally, a buffer width of at least 25 feet is recommended, but every little bit helps – do what you can! If you can only do one step from this list, this is the one you should do. Replace your lawn grass with native grass species and forbs (flowering plant) to turn that section of former-lawn into a beautiful native wildflower prairie.
2. Plan your Planting.
- Species: Native trees and shrubs adapted to floodplain and streamside conditions should be selected. Native grasses and wildflowers can be seeded as well. You’ll also want to consider site conditions such as amount of sun/shade.
- Number: For complete reforestation of a 25-foot wide buffer along a 50-foot long stream segment, you’ll want to plan on planting about 12-15 trees and fill in with gaps with at least that many shrubs.
- Spacing: The trees that will have the largest mature canopy should be planted at a distance of 20-25 feet from each other, then the rest of the trees filled in, maintain at least 10-12-foot spacing between trees. Shrubs can then be filled, and even clumped together, to fit the landscape of the planting site.
3. Plant your trees and shrubs.
The best times of year to plant trees are early spring and fall while the trees are dormant; this minimizes the shock of transplanting them into new ground. Mychorrhizae powders (sold at any garden store) can help the seedlings grow healthy root systems and reduce transplant shock.
4. Protect your trees.
- Deer:If you live in an area that gets browsed by deer, you’ll want to cage your trees. This can be done using chicken wire or welded wire fence, both of which are available at hardware stores and garden centers. The fence should extend at least to the tree’s dripline, and anchored with wooden stakes.
- Beaver: Deer protection will deter beavers as well. If you have beavers but not deer in your area, use the deer protection, but the perimeter of the cage can be closer to the trunk.
- Cicadas: While healthy, mature trees will easily be able to withstand any cicada damage, your younger trees will be more susceptible. If your trees are small enough, you can cover them with a nylon mesh netting (secure it by tying loosely around the trunk) during the period when the adult cicadas are active (probably for a couple weeks during May). Otherwise, check on your trees a couple times each day and remove any adult cicadas by hand.
Additional Resources
Woods For Waters: A guide to planting riparian buffers for healthy streams by Cuyahoga River Restoration
Tennessee's Urban Riparian Handbook (check any recommended plants species are also native to NE Ohio) and flyer on the benefits of riparian buffers.
LEAPBio and Cleveland Metroparks maintain an online list of regional native plant nurseries here.
Conservation Buffers: Design Guidelines for Buffers, Corridors and Greenways by USDA and the US Forest Service
And Cuyahoga SWCD’s own Life at the Water’s Edge: Living in Harmony with Your Backyard Stream
Blog author: Meg Hennessey, Watershed Coordinator