National Capital Parks-East - Forests

The parks of National Capital Parks-East (NACE) occur within the Oak-Pine Forest Region of the Atlantic Slope. These forests are characterized by the presence of species of pine, oak and hickory. Deciduous woodland is the most common cover type found in the parks. At elevations slightly higher than the floodplain forests, tree species such as Rock Chestnut Oak (Quercus prinus), White Oak (Quercus alba), American Beech (Fagus grandifolia), and Tulip Poplar (Liriodendron tulipifera) dominate the canopy. On the drier deciduous woodlands of the Tertiary Slopelands and the Southern Maryland Uplands species such as Southern Red Oak (Quercus falcata), Black Oak (Quercus velutina), Mockernut-hickory (Carya tomentosa) and American Holly (Ilex opaca) become more common and species such as Black-jack Oak (Quercus marylandica) have been found to be restricted to these higher, drier elevations.

The Ravine Forests are distinguished from other deciduous woodlands by their high, steep bank slopes, calcareous soils and their associated calciphilic flora. Paleocene fossil outcrops abound in the glauconite rich gray clay substrata of the creek banks exposed under the deep rich surface soils. The primary example of this habitat occurs along the upper reaches of Accokeek Creek and its maze of tributaries in Piscataway Park. Other examples are found at Johnson’s Gully and the Reserve Road Ravine in Piscataway Park and the ravines in Fort Washington Park. Canopy species that typify this habitat are Northern Red Oak (Quercus rubra), Yellow Oak (Quercus muehlenbergii) and Bitternut Hickory (Carya cordiformis). The steep Tertiary Slopelands at the mouth of Piscataway Creek in Fort Washington Park are also characteristic of the Ravine Forest habitat. This slope contains large populations of Quercus muehlenbergii and Sweet Pignut Hickory (Carya ovalis).

Mixed deciduous/coniferous woodland is uncommon in the parks of NACE. Although Virginia Pine (Pinus virginiana) is found throughout NACE parks, it rarely reaches 20% of the cover type. Exceptions occur along the eastern edge of the Potomac River Lowland just southwest of Bull Cove in Piscataway Park and in Greenbelt Park.