Physiognomy and Structure: No Data Available

Floristics: The vegetation is a closed forest strongly dominated by large and apparently even-aged Quercus phellos. Liquidambar styraciflua is frequent in the subcanopy and is second in abundance in the tree layer. Acer negundo and Nyssa sylvatica are also frequent in the subcanopy. Other bottomland and some upland trees occur as minor associates, including Fraxinus americana, Ulmus americana, Acer rubrum, Fraxinus pennsylvanica, Carya cordiformis, Quercus bicolor, Quercus palustris, and Liriodendron tulipifera. The shrub layer cover is open to moderately dense with Viburnum prunifolium most abundant. Woody vines are moderately important. The herb layer is quite diverse but heavily dominated by invasive exotics, including Microstegium vimineum, Alliaria petiolata, Lonicera japonica, and many others. Small remnant populations of native herbs such as Arisaema triphyllum, Amphicarpaea bracteata, Claytonia virginica, and Allium canadense are consistent with a well-drained floodplain.

Dynamics:  Both Quercus phellos and Liquidambar styraciflua are rare in the Potomac Gorge and are much more characteristic of the Coastal Plain at this latitude. The dynamics of this association are difficult to explain, but the even-aged character of the stand and its location adjacent to an area (C&O Canal) that has seen extensive disturbance both suggest an old successional forest. It seems likely that the floodplain occupied by this type was formerly cleared or at least heavily impacted during the construction of the canal, since the opposite side is a steep bluff that would not have provided any staging areas for the construction. The presence of large, in-place outcrops (confirmed by a geologist) in the floodplain is also quite unusual and contrasts sharply with a few localized depressions that support species such as Quercus palustris and Quercus bicolor. Since both Quercus phellos and Liquidambar styraciflua are also characteristic of depressions and this forest occupies the "backswamp" position in the floodplain, another hypothesis is that more of the area was originally low and poorly drained but has been covered by relatively recent flood-deposited alluvium. This might also account for the source of Quercus phellos and Liquidambar styraciflua if they invaded a cleared or heavily disturbed site many decades ago. The disturbed, exotic-dominated herb layer adds to the difficulties of interpretation.