Southern Interior Low Plateau Oak Forest

This system of upland hardwood-dominated forests occurs in the Interior Low Plateau region of the southeastern United States along ridgetops and slopes of various aspects. The system includes essentially all upland hardwood stands of the region except for mesic hardwood forests (which are accommodated by South-Central Interior Mesophytic Forest (CES202.887)). The floristic expression of different stands included in this system varies considerably with aspect and soil type. Included here are a variety of associations ranging along a moisture gradient from submesic to drier ones. The submesic to dry-mesic expressions tend to be found on midslopes with northerly to easterly aspects, and the drier ones on southerly to westerly aspects and on broad ridges. Parent material can range from calcareous to acidic with very shallow, well- to excessively well-drained soils in the drier expressions and moderately well-drained soils in the submesic to dry-mesic ones. The canopy closure of this system ranges from closed to somewhat open in the drier examples. Historically, these examples may have been more open under conditions of more frequent fire.

A number of different Quercus species may dominate stands of this system, with Carya species also prominent. In some drier examples on more acidic substrates, Quercus montana is typical over most of the range, reflecting relations with other Appalachian systems to the east. In addition, Quercus stellata, Quercus marilandica, and Quercus coccinea will also share dominance or be prominent in many of the drier examples. Quercus muehlenbergii and/or Quercus shumardii may appear in drier examples with high base status. Quercus alba may also be present but not typically dominant. In the submesic to dry-mesic examples, Quercus alba will typically exhibit dominance, possibly with Quercus velutina or Quercus falcata. The understories are typically shrub- and small tree-dominated, with the typical species varying with aspect, soil, and moisture relations.

A number of different Quercus species may dominate stands of this system, with Carya species also prominent. In the drier examples, Quercus montana (= Quercus prinus) is typical over most of the range, reflecting relations with other Appalachian systems to the east. In addition, Quercus stellata, Quercus marilandica, and Quercus coccinea will also share dominance or be prominent in many of the drier examples. Quercus muehlenbergii and/or Quercus shumardii may appear in drier examples with high base status. Quercus alba may also be present but not typically dominant. In the submesic to dry-mesic examples, Quercus alba will typically exhibit dominance, possibly with Quercus velutina or Quercus falcata. The understories are typically shrub- and small tree-dominated, with the typical species varying with aspect, soil, and moisture relations. Some typical species include Cornus florida, Cercis canadensis, Oxydendrum arboreum, Vaccinium pallidum, Vaccinium stamineum, Vaccinium arboreum, other highbush Vaccinium species, Kalmia latifolia, Viburnum acerifolium, Styrax americanus, and others. Some more open and drier stands may exhibit an understory of grassland species such as Schizachyrium scoparium, Danthonia spicata, and others. Forbs of the Fabaceae (e.g., Desmodium) and Asteraceae (e.g., Helianthus) will be prominent in many examples.

This system encompasses a variety of associations ranging along a moisture gradient from submesic to drier ones. The submesic to dry-mesic expressions tend to be found on midslopes with northerly to easterly aspects, the drier ones on southerly to westerly aspects and on broad ridges. Parent material can range from calcareous to acidic with very shallow, well- to excessively well-drained soils in the drier expressions and moderately well-drained soils in the submesic to dry-mesic ones.

This system occurs in the southeastern Interior Highlands of the Interior Low Plateau region, including southern Indiana and a small part of southeastern Ohio.