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PROBLEM: Once
entirely forested, over 75 percent of the forest cover in the Anacostia
watershed has been lost as a result of land clearing resulting from
agriculture, timber harvesting activities, as well as the urbanization
that has taken place. Much of this loss has occurred in the riparian
forest areas along the stream and river banks, where forests play a
critical role in maintaining stream temperature and water quality, preventing
stream bank erosion and providing aquatic and terrestrial habitat.
Results
from a recent assessment of riparian forest buffers in the Maryland
portion of the Anacostia revealed that nearly 60 percent of all stream
miles lack an adequate buffer of at least 150 feet on each side (Warner,
1996). As seen in Figure 40, Beaverdam Creek is the only remaining subwatershed
with a relatively intact riparian buffer zone.
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| Figure
40. Anacostia Subwatersheds Riparian Forest Buffer, 1992* (modified
from Warner et al., 1996). |
STRATEGY: Minimize
the loss of forest cover associated with new development and other activities
by sound environmental planning as well as the local implementation
of the 1991 Maryland Forest Conservation Act. Continue to reforest riparian
and upland sites throughout the watershed. Design and implement riparian
reforestation projects in critical areas of the watershed that will
ultimately provide a continuous corridor of forest from the tidal river
to the uppermost headwater streams.
PROGRESS:
Riparian
Buffer Reforestation
In
1993, the Maryland Department of Natural Resources assigned a forester
to the Anacostia watershed. Since then, the forester has coordinated
the planting of more than 25,000 trees on approximately 50 acres and
has also been active in public outreach activities.
Local
and regional agencies and non-profit groups, to include the Maryland-National
Capital Park and Planning Commission, Montgomery County Department of
Environmental Protection, Prince George=s County Department of Environmental
Resources, D.C. Forest Council, Anacostia Watershed Society and the
Metropolitan Washington Council of Governments, have reforested an estimated
40 acres. Much of the impetus has come from mitigation requirements
created by county tree ordinances, buffer criteria and the Chesapeake
Bay Critical Area program.
The
District of Columbia, through its urban forester (hired in 1991), is
exploring options with Federal landowners to reforest approximately
2.7 miles of riparian zone along the Anacostia.
The
Metropolitan Washington Council of Governments is, on behalf of the
District of Columbia Environmental Regulation Administration, working
to reforest eight acres of riparian forest in and around the District
of Columbia. Some of this acreage is being addressed in coordination
with the Maryland Anacostia Forester.
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| Figure
41. Joint COG/MD DNR/Anacostia Watershed Society Tree Planting
at University of Maryland Pond - Paint Branch. |
Many
civic associations and environmental groups, such as the Anacostia
Watershed Society, D.C. Cares, Green Democrats, Eyes of Paint Branch
and others, have been planting trees throughout the District of Columbia
and Montgomery and Prince George=s counties (Figure 41).
From
1994 to 1996, the Maryland Department of Natural Resources planted
20,000 seedlings and 150 containerized trees on approximately 30 acres
at the U.S. Department of Agriculture=s Beltsville Agricultural Research
Center.
Native
Seed Bank
In
1993, the Metropolitan Washington Council of Governments and the Earth
Conservation Corps collected native seeds from local trees which were
later propagated and planted in the watershed through a National Tree
Trust program.
Reforestation
Site Maintenance
From
1994 to 1996, the Metropolitan Washington Council of Governments,
in coordination with D.C. Cares, organized eight reforestation site
maintenance events in the watershed.
Anacostia
Floodway
As
part of its Section 1135 Anacostia Floodway Rehabilitation project,
the U.S. Army Corps of Engineers, in 1995 and 1996, planted over 600
trees to increase shading of the Northeast and Northwest Branch channels.
No-Mow
Riparian Buffers
As
part of its Upper Sligo Creek riparian zone no-mow policy, the Maryland-National
Capital Park and Planning Commission, in 1989, discontinued mowing
along the stream. This has resulted in the regeneration of approximately
10 acres of riparian forest.
Since
1994, the U.S. Department of Agriculture=s National Arboretum has
modified their mowing policy to promote the regrowth of a natural
buffer along a major tributary to Hickey Run.
The
National Park Service has modified its mowing policy to promote a
natural buffer along portions of the tidal river in the District of
Columbia. It has also supported several citizen-based tree plantings.
At
the request of the Metropolitan Washington Council of Governments
and the Interstate Commission on the Potomac River Basin, the U.S.
Department of Agriculture's Beltsville Agricultural Research Center
(in 1989) discontinued its channel maintenance practice of mowing
all riparian vegetation down to the waterline along Paint and Little
Paint Branch. By 1996, this resulted in the natural regeneration of
approximately 12 acres of woody riparian vegetation and an improvement
in both canopy coverage and instream habitat (Figures 42 and 43).
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| Figure
42. Paint Branch BARC 1989. |
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| Figure
43. Paint Branch BARC 1996. |
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