What is a riparian corridor?
A riparian corridor (or riparian zone) is the strip of vegetation along a river. This vegetation acts as a filter between landscape areas and the river’s ecosystem.
The challenge for the Olentangy River
This habitat area is especially in need of protection along the Olentangy River in Delaware county. The riparian corridors are often removed in neighborhoods to create a highly groomed look and to give a better view of the water. If this practice continues in Delaware county, the Olentangy is at a greater risk of losing its exceptional habitat status
Some of the benefits that a riparian corridor provides include:
➢Reduced fertilizer and other chemical and sediment runoff
➢Food source for instream wildlife
➢Corridors and beneficial habitat for terrestrial wildlife
➢Minimize use of pesticides and fertilizers. Only use pesticides approved for near-water areas in the riparian zone.
➢Keep pet waste out of the riparian zone.
➢Establish a no mow zone.
➢Control for invasive vegetation.
➢Plant native vegetation along corridor.
➢Keep and maintain natural rock structures.
➢Keep downed woody debris, a vital habitat to many organisms.
➢Use erosion and sediment controls such as silt fences and sediment traps during construction.
➢ Avoid building stream crossings. If they are necessary, do not disrupt stream flow, channel meandering, or fish passage.
➢Limit the clearing of vegetation.
➢Minimize heavy machinery use near the riparian corridor.
➢Avoid removing woody debris unless absolutely necessary.
➢After construction, plant native trees, shrubs and grasses in the riparian area.
A healthy riparian corrider provides landowners with:
➢Aesthetically pleasing fall colors, spring flowers, and summer shade
➢Community interaction through invasive removal and native planting projects
➢Increased property values
➢Lower costs for mowing, fertilizing, and watering
Healthy riparian corriders provide:
Water quality benefits
➢Effectively removes pollutants before they reach the stream
➢Provides bank stabilization
➢Filters sediments, preventing muddy water
Benefits to instream wildlife
➢Moderates stream temperature extremes, which can be harmful to fish
➢Provides cover to protect stream organisms
➢Provides leaves, branches, trunks, and insects that fall into streams, where they feed organisms
Benefits to land wildlife
➢Serves as corridors for mammals and birds
➢Provides nesting habitat for birds and amphibians
➢Protects pollinators because fish eat creatures that prey on pollinators
You can protect existing riparian habitat
➢Save money by using existing native vegetation and seed sources
➢Remove any disturbances from the area, including logging and soil compaction
➢Remove invasive species
➢See the Maintenance section
Before planting, remove invasive species!
Common invasive species in riparian zones:
multiflora rose (Rosa multiflora)
purple loosestrife (Lythrum salicaria)
tree-of-heaven (Ailanthus altissima)
autumn olive (Elaeagnus umbellata)
privet (Ligustrum spp.)
English ivy (Hedera helix)
Japanese knotweed (Polygonum cuspidatum)
garlic mustard (Alliaria petiolata)
kudzu (Pueria montana).
➢Select native species that tolerant flood and shade tolerant and that naturally occur in wetlands.
➢Test soil to determine whether changes are needed to accommodate the species that will be there.
➢Research the naturally-occurring species in this area. This can be historical documentation of natural conditions or successful riparian restoration projects near your area. FLOW can provide case studies from this area.
Invasive species removal
Inspect for regrowth of invasive species after the first year. They are the most common cause of tree mortality in riparian buffer systems.
Survey trees once in late fall for the first four years to estimate survival:
Row count Count live trees in a row, divide by number of trees planted in that row. Repeat throughout planting.
Plot method Sample 1% to 5% of the area with an 11.7 foot radius plot. Space plots evenly in a grid-like manner. Count living/regenerated trees.
Tally method Tally live trees throughout entire area. Mark counted trees to avoid double-counting.
Troubleshoot any problems influencing tree growth and survival.
If tree loss is substantial, remove invasives and then plant more trees.
|Angled cuts||Beavers||Tree shelters (tubes around trunks)|
|Seedlings nibbled to the ground||Deer||Tree shelters (tubes around trunks)|
|Gnawing at the base of trees||Mice||Mouse traps, raptor perches, mowed strip outside of riparian buffer|
|Roots of trees eaten, root structure weakened||Voles||Mouse traps, raptor perches, mowed strip outside of riparian buffer|
|Trees dry and browning||Drought||keep seedlings shaded and roots moist while planting|
|Seedlings and shelters pushed down in the same direction||Floods||Straighten seedlings after each flood|
|Dead tops or branch tips||Insects||Integrated Pest Management (search for details on Internet)|
|Spotted and/or discolored leaves||Disease||Stop planting and consult an expert|
Bongard, P., & Wyatt, G. (2010). Riparian forest buffers for trout habitat improvement: Design of riparian forest buffers [Pamphlet]. MN: University of Minnesota.
Goebel, P. C., Hix, D. M., & Semko-Duncan, M. E. (2003). Identifying reference conditions for riparian areas of Ohio.
Hairston-Strang, A. (2005). Riparian forest buffer design and maintenance. Annapolis, MD: Maryland Dept. of Natural Resources, Forest Service.
United States, The United States Department of Agriculture (USDA), Natural Resources Conservation Service. (2002). Job Sheet – Riparian Forest Buffer (391) . The United States Department of Agriculture (USDA).
Machtinger, E. T. (2007). Riparian systems. Washington, DC: Natural Resources Conservation Service.
Palone, R. S. (1998). Chesapeake Bay riparian handbook: a guide for establishing and maintaining riparian forest buffers. Washington, DC: U.S. Dept. of Agriculture.