Riparian Forest Buffers
(As previously published in The Delmarva Farmer)
Tree Tips
By: Nevin Dawson
4/22/08
You pour your first cup of coffee for the morning, add cream and sugar, and take a sip. It’s too bitter! You
realize you forgot to stir, so you dunk the spoon and begin to move the dark liquid around in circles. The
faster the coffee moves, the more sugar crystals get picked up off the bottom and carried to the top of the
mug where they can dissolve and sweeten your drink.
A similar thing happens when rainwater runs across fields, gathering speed and volume as it moves. The
faster the rainwater moves, the more soil particles get picked up off the bottom and carried towards the
ditch, stream, or river, and generally the Chesapeake Bay in the Delmarva region. Different sizes of soil
particles, or sediment, behave differently and cause different problems. Large particles fall to the bottom,
smothering oysters and clogging boat channels. Small sediment particles tend to hang in the water rather
than settling on the bottom. These suspended particles block sunlight from reaching the floor where
underwater grasses would normally grow. Without enough sunlight, these grasses cannot grow and
provide critical habitat for fish and blue crabs.
Many pollutants can hitch a ride on sediment as it travels downstream, further degrading water quality.
Sediment is not the only problem that results from unrestricted runoff. Rainwater also carries nutrients
like nitrogen and phosphorous into the Bay. In the same way that these elements provide nutrition for
agricultural crops, they also feed algae floating in the water or growing on the leaves of underwater
grasses. Just like sediment, algae blocks sunlight from reaching grasses, limiting crab and fish habitat.
Algae that aren’t eaten die and fall to the bottom, where their decomposition consumes some of the
oxygen that’s dissolved in the water. The decomposition of large quantities of dead algae can remove
almost all of the oxygen in the water, leaving none for crabs, oysters, and other bottom-dwelling species.
What can you do to help?
Plant trees of course!
Trees and other plants that grow along ditches , streams, and other water bodies filter out both sediment
and nutrients. Leaves and branches on the forest floor slow down the flow of runoff so that soil particles
can drop out of the water. Plant roots in the soil absorb extra nutrients. Root systems also stabilize stream
banks, controlling erosion. Leaves and branches that fall into the water provide food and habitat for
aquatic wildlife, and the forest canopy shades the water, keeping it cool enough for high quality habitat.
This important area surrounding a water body is called a riparian buffer.
When choosing which trees to plant where, consider site conditions carefully. Species well-adapted to
wetter areas are silver maple, black willow, eastern cottonwood, green ash, and sycamore. Where the soil
is generally drier, black walnut, red and white oak, and white ash should do well. Shrubs and lowgrowing trees are also important for increased bank stability, water shading, and diverse habitat. Try to
plant species similar to what grows naturally on similar sites.
The best part is that if the land used to be cropland, you may be able to get help paying for the creation of
a riparian forest buffer, and then receive annual rental payments just for keeping your land in a
conservation practice. These payments may even be more than the income from cropping on the same
land. Call your county Farm Service Agency office and ask about the Conservation Reserve Program
(CRP) and the Conservation Reserve Enhancement Program (CREP). You may also be eligible for other
cost-share or incentive programs even if the land was not recently cropped.
Delmarva residents are well-schooled in both the ecological and economic importance of the Chesapeake
Bay, and in the poor current state of the Bay. The next time you stir in your sugar for the perfect cup of
joe, take a moment to think about the sediment and nutrients that could be stirred up on your land and
washed into the Bay the next time it rains. Then consider that you may have the opportunity not just to
make a difference, but to get paid for doing so.