About Oak Hickory Forests

Oak-Hickory Forests are widespread throughout the Piedmont. This forest type, forms the dominant forested land cover in the Piedmont of Virginia. It covers the vast majority of upland dry and well-drained landscapes on flat tops, north, south, east and west aspects. The only exception is the tendency for the forest to switch to a mountain laurel – chestnut oak dominated heath on northwest aspects. Steeper and deeper ravines give way to richer mesic mixed and basic mesic forests, and the flat bottoms, streams and floodplains harbor other forest types. The Oak-Hickory Forests of Virginia have a long history of disturbance. In prehistory they was managed by natural and man-made fires for game and mast production. This helped it evolve into the forest type we have now. More recent clearcutting for pasture, wheat, and other agricultural uses reset the ecological clock on 99% of the terrain supporting this forest type. Save for a few small patches here and there, all the Oak- Hickory Forests we see now are the result of modern regeneration. 19th and 20th century disturbances have shaped this new version of the forest type. For example, fire exclusion has reduced the recruitment of oaks and hickories and encouraged species such as red maple, American beech, and black gum. Proportionally speaking, the fact that agriculture decline is producing more forest landcover, and fire prevention is encouraging forest growth, we have more Oak-Hickory Forests now than in the evolutionary past. Savannas, woodlands, and prairies would have been co-dominant (and collectively dominant) in the Piedmont, and the Oak-Hickory Forests would have been modified to favor the American chestnut for its mast. Indeed, American chestnut prevalence at the time of colonial contact was likely a wildly unnatural balance due to the late woodland period agri-forestry practices that favored it over other trees. There are several variations of the Acidic Oak-Hickory forest in our region, but for the purposes of selecting species that are useful and attractive in the landscape arena, two will suffice. The first below is the Acidic variant, holding slightly fewer species that the Basic variant that follows. The use of the word “Basic” in this context is not a reference of pH, but rather of base (cation) saturation and exchange capacity. Basic Oak- Hickory forests have soils with greater ability to provide nutrients to plants, despite being acidic in pH.

Thanks to Devin Floyd of Center for Urban Habitats for assistance with words.