Riparian Corridors

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

➢Cooler water

➢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.

Ohio Invasive Plants Council

Ohio Department of Natural Resources Invasive

➢Plant native vegetation along corridor.

Midwest Native Plant Society

Ohio Department of Natural Resources Natives

➢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

➢Birdwatching

http://watercraft.ohiodnr.gov/scenic-rivers/program/stream-life/riparian-corridor-birds

➢Educational opportunities

➢Community interaction through invasive removal and native planting projects

➢Increased property values

➢Flood protection

➢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

Invasives

Before planting, remove invasive species!

Common invasive species in riparian zones:

japanese honeysuckle (Lonicera japonica)

bush honeysuckles (Lonicera maackii, Lonicera morrowii, Lonicera tatarica)

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).

Species selection

➢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.

Reinforcement planting

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.

Symptom Cause Solution
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.