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A3256 Quercus macrocarpa - Quercus alba Wooded Grassland Alliance

Type Concept Sentence: This fire-dependent, open woodland (or savanna) type is found in the midwestern United States and southern Canada, and is characterized by a dry-mesic and mesic tallgrass prairie understory and open oak canopy dominated by Quercus macrocarpa, sometimes with Populus tremuloides, Quercus alba, Quercus bicolor, and Quercus stellata. It is typically found on rolling outwash plains, hills, and ridges, as well as lakeplains near the Great Lakes.

Common (Translated Scientific) Name: Bur Oak - White Oak Wooded Grassland Alliance

Colloquial Name: Tallgrass Bur Oak Openings

Hierarchy Level:  Alliance

Type Concept: This open woodland (or savanna) type is found in the midwestern United States and southern Canada, and is characterized by a dry-mesic and mesic tallgrass prairie understory and open oak canopy. Canopy cover typically varies from 10-25%. Quercus macrocarpa is a common tree throughout the range of this alliance. Populus tremuloides (in the northern portion of this alliance''s range), Quercus alba, Quercus bicolor, and Quercus stellata can be found in some stands. The total tree canopy cover may exceed 30%. The dominant herbaceous species are graminoids Andropogon gerardii, Hesperostipa spartea, Schizachyrium scoparium, Sorghastrum nutans, and Sporobolus heterolepis. Other typical species include Amorpha canescens, Antennaria spp., Calamagrostis canadensis (in moist stands), Carex spp., Lespedeza capitata, Ratibida pinnata, Silphium laciniatum, and Zizia aurea. The shrub layer can be absent to prominent. Where shrubs are present, Corylus spp. tend to be dominant, accompanied by species such as Cornus foemina, Rosa spp., Rubus allegheniensis, and Symphoricarpos occidentalis (in the west). This type is typically found on rolling outwash plains, hills, and ridges, as well as lakeplains near the Great Lakes. Most soils are sandy to loamy. Some, especially near the Great Lakes, can be on clay loam. Stands typically require periodic fire.

Diagnostic Characteristics: Quercus macrocarpa is a common tree throughout the range of this alliance, with tree canopy cover ranging from (5)10-25(30+)%. The dominant herbaceous species are graminoids Andropogon gerardii, Hesperostipa spartea, Schizachyrium scoparium, Sorghastrum nutans, and Sporobolus heterolepis. Other typical species include Amorpha canescens, Antennaria spp., Calamagrostis canadensis (in moist stands), Carex spp., Lespedeza capitata, Ratibida pinnata, Silphium laciniatum, and Zizia aurea. Most soils are sandy to loamy. Some, especially near the Great Lakes, can be on clay loam.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: The term "savanna" is often applied to this vegetation, though the term "oak openings" is a common, historic name used for the vegetation (Curtis 1959). Canopy cover is here restricted to the more open condition (10-25%), but applications at the state level show a wide range in variation, including up to 70 or 80% cover. However, these conditions are better treated as part of a woodland type.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This open woodland (or savanna) type is characterized by a dry-mesic and mesic tallgrass prairie understory, often 1-2 m tall, with an open oak canopy cover of 10-25%. More closed-canopy conditions of up to 70 or 80% are sometimes included here when the understory remains strongly dominated by tallgrass species despite the denser canopy.

Floristics: This alliance, found in the midwestern United States and southern Canada, is characterized by a dry-mesic and mesic tallgrass prairie understory with a very open tree canopy. The dominant herbaceous species are graminoids Andropogon gerardii, Hesperostipa spartea (= Stipa spartea), Schizachyrium scoparium, Sorghastrum nutans, and Sporobolus heterolepis. Other typical species include Amorpha canescens, Antennaria spp., Calamagrostis canadensis (in moist stands), Carex spp., Lespedeza capitata, Ratibida pinnata, Silphium laciniatum, and Zizia aurea. Quercus macrocarpa is a common tree throughout the range of this alliance. Populus tremuloides (in the northern portion of this alliance''s range), Quercus alba, Quercus bicolor, and Quercus stellata can be found in some stands. The total tree canopy cover may exceed 30%. The shrub layer can be absent to prominent. Where shrubs are present, Corylus spp. tend to be dominant, accompanied by species such as Cornus foemina, Rosa spp., Rubus allegheniensis, and Symphoricarpos occidentalis (in the west).

Dynamics:  The fire dynamics for this alliance are described in the group description.
Environmental Description:  This alliance is found on a variety of sites. It occurs on lakeplains near the Great Lakes, but more commonly on rolling outwash plains, hills, and ridges (Curtis 1959, MNNHP 1993). Most soils are sandy to loamy. Some, especially near the Great Lakes, can be on clay loam. This alliance is maintained by periodic fire.
Geographic Range: This alliance is found in the midwestern United States and southern Canada.

Nations: CA,US

States/Provinces:  IA, IL, IN, MB, MI, MN, MO, ND, NE, NY, OH, ON, PA?, SD, WI


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 1 Forest & Woodland Class C01 1
Subclass 1.B Temperate & Boreal Forest & Woodland Subclass S15 1.B
Formation 1.B.2 Cool Temperate Forest & Woodland Formation F008 1.B.2
Division 1.B.2.Na Eastern North American Forest & Woodland Division D008 1.B.2.Na
Macrogroup 1.B.2.Na.4 White Oak - Bur Oak - Shagbark Hickory Forest, Woodland & Savanna Macrogroup M012 1.B.2.Na.4
Group 1.B.2.Na.4.a Bur Oak - Black Oak / Big Bluestem Savanna & Barrens Group G181 1.B.2.Na.4.a
Alliance A3256 Bur Oak - White Oak Wooded Grassland Alliance A3256 1.B.2.Na.4.a
Association CEGL002020 Bur Oak - (White Oak, Black Oak) / Big Bluestem Wooded Grassland CEGL002020 1.B.2.Na.4.a
Association CEGL002158 Bur Oak Northern Tallgrass Wooded Grassland CEGL002158 1.B.2.Na.4.a
Association CEGL002159 Bur Oak - (White Oak, Post Oak) / Big Bluestem Open Woodland CEGL002159 1.B.2.Na.4.a
Association CEGL005120 Bur Oak - Pin Oak - Swamp White Oak / Bluejoint Open Woodland CEGL005120 1.B.2.Na.4.a
Association CEGL005121 White Oak - Bur Oak / Big Bluestem Open Woodland CEGL005121 1.B.2.Na.4.a
Concept Lineage: A.1491

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Oak Openings (Curtis 1959) [Wisconsin]
Concept Author(s): J.T. Curtis (1959)

Author of Description: D. Faber-Langendoen

Acknowledgements: No Data Available

Version Date: 12-18-14
  • Curtis, J. T. 1959. The vegetation of Wisconsin: An ordination of plant communities. Reprinted in 1987. University of Wisconsin Press, Madison. 657 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.
  • Faber-Langendoen, D., and Midwest State Natural Heritage Program Ecologists. 1996. Terrestrial vegetation of the midwest United States. International classification of ecological communities: Terrestrial vegetation of the United States. The Nature Conservancy, Arlington, VA.
  • MNNHP [Minnesota Natural Heritage Program]. 1993. Minnesota''s native vegetation: A key to natural communities. Version 1.5. Minnesota Department of Natural Resources, Natural Heritage Program, St. Paul, MN. 110 pp.