The Accotink Gorge

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What is the Accotink Gorge?

I am hoping to get the word out to people who will be able to engage in some heavy duty invasive species removal work which will involve cutting down large Wisteria sinensis vines and hauling them away from the site. This may necessitate the use of special equipment. There are many wild areas in this region which are overrun with invasives, but this is one in which what could be saved by prompt removal is particularly amazing.

In the interest of preserving the unique biodiversity of the site, despite the fact that it is the fertile floodplain forest that is currently most seriously infested, the high dry rocky oak hickory forest, which is just starting to be invaded, is where the Wisteria sinensis removal should begin, as it contains the most uncommon species, and unlike the floodplain habitat, which has evolved in a state of continual disturbance, and should regenerate well, the ancient plant communities on the higher slopes, and the fragile soils which support them, once lost, will be lost forever.

In Accotink Stream Valley Park, in the southern portion of Accotink Gorge, exists one of the more diverse examples of oak hickory heath forest in the entire Fairfax County park system, where native trees and shrubs coexist with native grasses such as Danthonia spicata (Poverty grass), Piptochaetium avenaceum (Blackseed needlegrass), and Melica mutica (Twoflower melicgrass), as well as flowering herbaceous species such as Clitoria mariana (Butterfly pea), Aureolaria virginica (Downy false foxglove), Silene caroliniana (Wild pink), Symphyotrichum patens (Late purple aster), and Asclepias variegate (Variegated milkweed). There are also some extremely steep slopes in the oak hickory forest, with particularly acidic soil, where the Wisteria has been unable to invade, but the understory in these sections consists largely of Kalmia latifolia (Mountain laurel), and is not particularly species diverse.

Throughout Accotink Gorge, the priority should be saving the canopy trees that are still salvageable, starting at the higher elevations, once that is done, the understory can be dealt with. Based on the spring ephemerals that I observed before the Wisteria leafed out, the native floodplain forest understory vegetation has not died out yet, it is merely being suppressed by the Wisteria growing on top of it, and it should regenerate fast and well once the Wisteria is removed. The meadow created by the powerline cut which bisects this area is also quite biodiverse, providing habitat for sun loving native species including milkweeds and many grasses, whose populations have declined in natural areas due to fire suppression, however it is a distant last on the priority list for Wisteria removal. There are invasive species other than Wisteria in Accotink Gorge, but it is the Wisteria that is killing the canopy trees, and until that is dealt with, worrying about anything else is just a distraction.

I fell in love with this place as soon as I set foot there, and I hope to share this experience with other people who might be able to make a difference to save it. Despite seeing how fast the Wisteria has advanced over the course of just one year, and the fact that it has begun to actually topple over canopy trees, creating a nearly impenetrable thicket in some areas, I truly believe that it is not too late. The only plants that should be removed from this place are invasive species. I have come upon evidence of the poaching of large colonies of Epigaea repens (Ground laurel) from this location, and I want to make it very clear to anyone who may be misguided on the issue that removing native plants from an embattled natural area such as this is not a "rescue". Please leave all the native plants where they are so that they can revegetate the areas that will be disturbed in the process of Wisteria removal. Many of the species present in this very special area are only present in very small populations, for instance, there is only one Ionactis linariifolia (Flax-leaf ankle-aster) so, at least until the Wisteria has been removed, and populations of these native species have had a chance to recover, it is not even appropriate to collect a voucher specimen.

If you know anyone who would be able to help organize invasives removal work, please forward this to them and bring them into the discussion. It is my hope that this event will catalyze the community to come together and save this very special place for future generations.

Fritz Flohr Reynolds - July 7, 2015

Great Falls of the Accotink, at the confluence with Field Lark Branch

Flora photos here       7-7-15 Survey photos here
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