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A3217 Quercus stellata - Ulmus crassifolia Forest & Woodland Alliance

Type Concept Sentence: This alliance represents dry and dry-mesic woodland or forest vegetation characterized by Quercus stellata occurring in southern Oklahoma and central Texas.


Common (Translated Scientific) Name: Post Oak - Cedar Elm Forest & Woodland Alliance

Colloquial Name: Southern Crosstimbers & Texas Post Oak Forest & Woodland

Hierarchy Level:  Alliance

Type Concept: This alliance occurs in a variety of dry and dry-mesic landscape settings in the southern Crosstimbers of Oklahoma, and the Crosstimbers, Edwards Plateau and Post Oak Savannah regions of Texas. It is characterized by an open to closed tree canopy dominated by Quercus stellata. Other canopy associates may include Ulmus crassifolia, Carya texana, Quercus marilandica, Quercus fusiformis, Quercus virginiana, Quercus buckleyi, or Quercus incana depending on substrate and location. This alliance occurs west of the range of Quercus falcata, Quercus alba, Quercus coccinea, Quercus velutina, and Pinus echinata. Woodland examples often have high cover of Schizachyrium scoparium and other grasses from adjacent prairies. Forest examples may have high cover of a variety of shrubs in the understory. These forests and woodlands are found in a variety of landscape settings from level plains to rolling hills to rocky hilltops. Substrates are variable and may include sands to clay loams over sandstone, limestone, granite, or sedimentary formations in the coastal plain. Fire and grazing are thought to play a role in maintaining this vegetation.

Diagnostic Characteristics: Characterized by Quercus stellata and Ulmus crassifolia west of the range of Quercus falcata, Quercus alba, Quercus coccinea, Quercus velutina, and Pinus echinata. The tree canopy is dominated or codominated by Quercus stellata and Ulmus crassifolia. Other canopy associates may include Carya texana, Quercus fusiformis, Quercus virginiana, Quercus buckleyi, and Quercus incana.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance is broadly defined and floristically variable depending on substrate and geography. It may warrant splitting. It could also be broadened to include ~Quercus stellata - Quercus virginiana / Ilex vomitoria Forest & Woodland Alliance (A0668)$$. More information is needed to flesh out detailed floristic, environment, and range of this alliance. Some of this will likely include describing new associations.

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: These communities are physiognomically variable, locally varying from deciduous to mixed, often having substantial canopy closure, especially as a result of fire suppression.

Floristics: Quercus stellata is a constant and diagnostic canopy dominant of this wide-ranging alliance, but the floristic composition of associated woody species can be quite variable. Canopy and subcanopy associates, in addition to Quercus stellata and Quercus marilandica, may include Carya texana, Cornus florida, Ulmus crassifolia, Juniperus virginiana, Juniperus ashei, Quercus fusiformis, Fraxinus albicans (= Fraxinus texensis), Diospyros virginiana, Diospyros texana, Cercis canadensis, Forestiera pubescens, and Sideroxylon lanuginosum. Shrubs may be sparse to dense.

Dynamics:  Fire, climate, native grazing and edaphic factors all likely played a role historically in maintaining an open structure in this vegetation. Loss of these natural processes often results in a shift toward a more closed canopy, an increase in successional woody species, and a decrease in native grass cover.

Environmental Description:  These forests and woodlands are found in a variety of landscape settings from level plains to rolling hills to rocky hilltops. Substrates are variable and may include sands to clay loams over sandstone, limestone, granite, or sedimentary formations in the coastal plain. Fire and grazing are thought to play a role in maintaining this vegetation.

Geographic Range: This vegetation occurs in the southern Crosstimbers of Oklahoma, and the Crosstimbers, Post Oak Savannah, and Edwards Plateau regions of Texas.

Nations: US

States/Provinces:  AR, OK?, TX




Confidence Level: Low

Confidence Level Comments: No Data Available

Grank: GNR

Greasons: No Data Available


Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: ? Quercus marilandica woodland alliance (Hoagland 1998a)
? Quercus stellata - Quercus marilandica woodland alliance (Hoagland 1998a)

Concept Author(s): J. Teague, in Faber-Langendoen et al. (2013)

Author of Description: J. Teague

Acknowledgements: No Data Available

Version Date: 12-18-14

  • Diamond, D. D. 1993. Classification of the plant communities of Texas (series level). Unpublished document. Texas Natural Heritage Program, Austin. 25 pp.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Hoagland, B. W. 1998a. Classification of Oklahoma vegetation types. Working draft. University of Oklahoma, Oklahoma Natural Heritage Inventory, Norman. 43 pp.