Wilburdale Park: A Forest Buffer for Backlick Run
This small stream-valley park in the Annandale section of Fairfax County encloses 2,200 feet of Backlick Run, a large, degraded stream that drains about one-third of the 42-square-mile Cameron Run watershed.
Wilburdale Park consists of some eight acres of forest and playing field. It is owned by the Fairfax County Park Authority and is the first public property through which Backlick Run passes, after emerging from the ground about 2,300 feet upstream from the park’s northern boundary. About two-thirds of the park is forest—and Wilburdale’s trees make up the largest patch of forest remaining along the piedmont section of the stream. (Backlick Run is 7.2 miles long; it flows through the piedmont for about 3.5 miles before entering the coastal plain.)
Wilburdale’s forest is not especially remarkable but, for a small patch, it is fairly rich in the native plant species that grow on moist soils in the mid-Atlantic region. The canopy includes red maple (Acer rubrum), silver maple (Acer saccharinum), tulip-tree (Liriodendron tulipifera), American beech (Fagus grandifolia), green ash (Fraxinus pennsylvanica), and several oak (Quercus) and hickory (Carya) species. In the understory, you can find common hackberry (Celtis occidentalis), American hornbeam (Carpinus caroliniana), eastern flowering dogwood (Cornus florida), blackhaw (Viburnum prunifolium), mapleleaf viburnum (Viburnum acerifolium), and spicebush (Lindera benzoin). Native species of the forest floor include wild ginger (Asarum canadense), black snakeroot (Sanicula canadensis), false Solomon’s seal (Smilacina racemosa), trout lily (Erythronium umbilicatum), and skunk cabbage (Symplocarpus foetidus).
But like many local woodlands, Wilburdale’s forest is threatened by two of the DC area’s biggest environmental problems: high-volume stormwater run-off and invasive alien plants.
When the Earth Sangha started work at Wilburdale in 2002, much of the park was choked with dense infestations of European privet (Ligustrum vulgare), multiflora rose (Rosa multiflora), and several other alien shrub species. Some parts of the park had been reduced to invasive thickets so dense that the forest could not regenerate—tree saplings could not come up through the invasives. Many of the large trees were heavily encumbered by Oriental bittersweet (Celastrus orbiculatus), English ivy (Hedera helix), Japanese wisteria (Wisteria floribunda), and other invasive vines. These vines interfere with the growth of the trees and make them more likely to topple in heavy wind. On the forest floor, there was (and is) a substantial infestation of garlic mustard (Alliaria petiolata), which displaces native herbs (non-woody plants) and secretes chemicals that can suppress tree seedlings.
And because 30 percent of the Backlick Run drainage is now covered by roads, parking lots, and buildings, Wilburdale is suffering the effects of heavy stormwater runoff. (To learn more about this problem, read our Stream Buffer page.) The Wilburdale reach of Backlick Run has grown increasingly unstable. Channel erosion in the downstream section of the park has dropped the stream bed nearly five feet below the floodplain, and an increasing number of large trees along the stream are being undermined. Since we started work at Wilburdale, we have lost one large northern red oak (Quercus rubra) and several others are likely to fall as well.
In collaboration with the Fairfax County Park Authority and our other partners, we are restoring Wilburdale’s forest by controlling the invasive species and planting native plants, grown at our Wild Plant Nursery. We are also looking for ways to help stabilize the stream channel.
Our Partners at Wilburdale
We are grateful to the following organizations, who have helped fund our work at Wilburdale, or have provided substantial support for our efforts there.
The DC-Area Chapter of the Art of Living Foundation,
The Fairfax County Park Authority,
The GW Community School,
Homestretch,
The National Tree Trust and the Arbor Day Foundation,
The Northern Virginia Community College Botany Class led by Professor Lisa Williams,
Patagonia, and
The Virginia Department of Forestry
Where to Find More Information
Our work at Wilburdale is covered in our Wilburdale Park slide show, and in our booklet, Reconnecting Forests and Streams, which shows some of our work in the park’s most infested area. For recent activities on sites described in the Special Places page, look at the Special Places News.