Name:
A.1920
Reference:
EcoArt 2002
Description:
This alliance includes ~Schizachyrium scoparium$-dominated grasslands with scattered broad-leaved deciduous trees, or mixed broad-leaved deciduous trees with needle-leaved evergreen trees such as ~Juniperus virginiana var. virginiana$. Graminoids dominate stands of this alliance with scattered trees and shrubs. Various combinations of ~Quercus$ spp. and ~Juniperus virginiana$ may be present, with ~Quercus stellata$ and ~Quercus marilandica$ being the most common trees, although ~Quercus velutina$ may often be present. ~Andropogon virginicus, Schizachyrium scoparium, Danthonia spicata$, and ~Dichanthelium$ spp. are the most abundant herbs. Some other herbs which may be found include ~Castilleja coccinea, Coreopsis tripteris, Liatris$ spp., ~Rudbeckia$ spp., ~Silphium$ spp., ~Carex$ spp., and ~Asclepias amplexicaulis$. ~Smilax glauca, Smilax bona-nox, Rhus aromatica, Toxicodendron radicans, Ulmus alata$, and ~Vaccinium arboreum$ make up the sparse to moderate shrub layer. Lichens (e.g., ~Cladonia$ spp. and ~Cladina$ spp.) and mosses are prominent on exposed rock. Stands occur on exposed slopes throughout the range of this alliance. In Missouri, they occur on moderate to steep slopes of dissected drainages along major streams and mounds. The soil is absent to thin (0-40 cm) and somewhat rapidly to very rapidly drained. The parent material is variable; it is most typically shale or sandstone, with siltstone present in Indiana occurrences. Exposed bedrock or fragments of parent material are common on or at the surface. In Virginia's Blue Ridge, an association occurs over amphibolite, which weathers to produce high base status soils. Some associations are over various igneous materials, e.g., nepheline syenite in Arkansas. Most associations in this alliance occur over soils that are stony, shallow, and typically acidic, primarily consisting of weathered mineral matter, loess, and organic debris which collects in cracks and crevices of the bedrock. Organic matter is low, and clay content can be quite high. These soils are extremely susceptible to erosion and downslope migration, especially on steeper slopes and during periods of freeze-thaw. All these factors contribute to poor productivity and provide only shallow root penetration for vegetation. Although predominantly droughty and excessively drained, these sites can be seasonally wet; water is occasionally ponded in shallow depressions.
Accession Code:
VB.CC.1621.A1920
Plot-observations of this Community Concept:
0
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