Name:
Quercus macrocarpa - Quercus velutina / Andropogon gerardii Savanna & Barrens Group
Reference:
NatureServe Biotics 2019
Description:
The deep-soil oak savanna occurs in the northern, central and southern tallgrass prairie regions of the central United States, with extensions into southern Ontario and southeastern Manitoba, Canada. It was historically dominant in the northern glaciated regions of the Midwest with the largest concentration in the prairie-forest border ecoregion. It is typically found on rolling outwash plains, hills and ridges. Soils are typically moderately well- to well-drained deep loams. This savanna is typified by scattered trees, varying from 10 to 30% cover over a more-or-less continuous tallgrass prairie layer. <i>Quercus macrocarpa</i> is a common tree throughout the range. Other associates include <i>Populus tremuloides</i> (northern portion of the range), <i>Quercus alba, Quercus bicolor</i>, and <i>Quercus stellata</i>. The dominant herbaceous species are the graminoids <i>Andropogon gerardii, Schizachyrium scoparium, Sorghastrum nutans, Sporobolus heterolepis</i>, and <i>Hesperostipa spartea</i>. A rich forb component includes <i>Amorpha canescens, Antennaria</i> spp., <i>Calamagrostis canadensis</i> (in moist stands), <i>Carex</i> spp., <i>Lespedeza capitata, Ratibida pinnata, Silphium laciniatum</i>, and <i>Zizia aurea</i>, among many species. The shrub layer can be absent to prominent. Where shrubs are present, <i>Corylus</i> spp. tend to be dominant, accompanied by species such as <i>Cornus foemina, Rosa</i> spp., <i>Rubus allegheniensis</i>, and <i>Symphoricarpos occidentalis</i> (in the west). Historically, frequent fires maintained this savanna within its range and would have restricted tree canopies to 10-30% cover. Fire suppression in the region has allowed trees to establish more dense canopies. Periodic, strong wind disturbances and browsing also impact this type. Much of this type has also been converted to agriculture, or succeeded to forests because of the lack of fire, greatly reducing its area and range.<br /><br />The sandy oak barrens occur on well-drained, coarse-textured sandy soils derived from glacial outwash, end moraine formations, or lakeplain dune systems in the north-central U.S. and parts of southern Ontario, Canada. Soils range from almost pure sand, to loamy sand, to sandy loam. The soils have low fertility, organic matter, and moisture-retention capacity. Factors which affect seasonal soil moisture are strongly related to variation in this type. The oak barrens is a scrubby, open-treed system dominated by graminoids and shrubs. Canopy structure varies from a dominant herbaceous ground layer with sparse, scattered "savanna" canopy (5-25%), through oak-dominated scrub, to a more closed woodland canopy (25-60%). The canopy layer is dominated by <i>Quercus velutina</i>, with some <i>Quercus ellipsoidalis, Quercus macrocarpa</i>, and <i>Quercus alba</i> (the latter more common eastward and in woodland conditions). Occasional <i>Pinus banksiana</i> can occur in the northern parts of the range. Species found in the herb layer include <i>Ambrosia psilostachya, Amphicarpaea bracteata, Artemisia ludoviciana, Andropogon gerardii, Calamovilfa longifolia, Carex pensylvanica, Carex</i> spp., <i>Comandra umbellata, Sorghastrum nutans, Hesperostipa spartea</i>, and <i>Schizachyrium scoparium</i>. Fire was an important factor in maintaining this community. Oak wilt and droughts also reduce tree cover.
Accession Code:
urn:lsid:vegbank.org:commConcept:39984-{59CB0AAE-9107-4418-A853-789E462AA4F1}
Plot-observations of this Community Concept:
0
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