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For information on Wisconsin's natural communities, contact:
Ryan O'Connor
Natural Heritage Inventory Ecologist

Oak Woodland

State Rank: S1?     Global Rank: GNR   what are these ranks?


Detailed Community Description from Ecological Landscapes of Wisconsin

General natural community overview

Counties shaded blue have documented occurrences for Oak Woodland in the Wisconsin Natural Heritage Inventory database.

The oak woodland community occupies a position on the vegetation continuum that is intermediate between the oak savannas (especially oak openings) and the oak forests (especially southern dry forest). Oak woodlands differ from oak openings in that they lack the wide-spreading crowns and thick boles associated with savannas, and they have greater crown closure, with an approximate range of 50-95%. As presently understood, the latter attribute is not simply the result of the canopy closure that affected most savannas following the implementation of wildfire suppression policies earlier in the 20th century. As soon as fire suppression policies were widely implemented in southern Wisconsin, the rapid proliferation of shrubs and saplings would have quickly altered stand structure, causing the open understories of the oak woodland communities to disappear. Describing the differences between woodland and forest is difficult because of the absence of intact reference stands, but the oak woodlands were subjected to frequent (annual) wildfires of low intensity, lacked the dense woody understory that characterizes most dry oak forests, and often had relatively lower canopy closure than true forests.

Dominant trees included white oak (Quercus alba), bur oak (Quercus macrocarpa), and black oak (Quercus velutina), sometimes mixed with red oak (Quercus rubra) and shagbark hickory (Carya ovata). Under a characteristic fire regime, shrub and sapling representation in oak woodlands would be minimal. The herb layer is potentially diverse, including some members of the prairie, oak savanna, and oak forest communities, but also featuring grasses, legumes, composites, and other forbs that are best adapted to light conditions of highly filtered shade. Representative herbs may include upland boneset (Eupatorium sessilifolium), violet bush-clover (Lespedeza violacea), Virginia bush-clover (Lespedeza virginica), Culver's-root (Veronicastrum virginicum), rough-leaved sunflower (Helianthus strumosus), eastern shooting-star (Primula meadia), Short's aster (Symphyotrichum shortii), yellow-pimpernel (Smyrnium integerrimum), bottlebrush grass (Elymus hystrix), silky wild-rye (Elymus villosus), and bracted tick-trefoil (Desmodium cuspidatum).

Many of the same plants and animals that reach their optimal abundance in the oak openings also occur in oak woodlands, including Red-headed Woodpecker, Orchard Oriole, Eastern Bluebird, and kitten-tails. Oak woodland can also support forest species, such as Yellow-throated Vireo, Scarlet Tanager, Tufted Titmouse, and Blue-gray Gnatcatcher, and in large stands, some species that are restricted to forest interior conditions, such as the Cerulean Warbler.

Historically, the geographic range of oak woodland would be virtually the same as that of oak openings and prairies in southern Wisconsin. Oak woodlands would have been most common on sites that experienced frequent, low-intensity ground fires. Moisture conditions would have included dry, dry-mesic, mesic, and, possibly, wet-mesic sites. Today oak woodlands are most likely to occur in those parts of southern Wisconsin that continue to support relatively large areas of natural vegetation that include prairie and savanna remnants in proximity to oak-dominated forests. Portions of the Driftless Area, the kettle interlobate moraine of southeastern Wisconsin, and perhaps portions of the Central Sand Hills, offer the best potential. This type is extraordinarily rare today.

Rare animals

Species of Greatest Conservation Need

Wisconsin Wildlife Action Plan graphic

The following Species of Greatest Conservation Need are listed according to their level of association with the Oak Woodland natural community type, based on the findings in Wisconsin's 2015 Wildlife Action Plan.

Scores: 3 = high association, 2 = moderate association, and 1 = low association. See the key to association scores for complete definitions.

Ants, wasps, and beesScore
Confusing Bumble BeeBombus perplexus1
Rusty-patched Bumble BeeBombus affinis1
Yellowbanded Bumble BeeBombus terricola1

A Leaf BeetlePachybrachis atomarius1
A Leaf BeetleCryptocephalus cuneatus1
A Pear-shaped WeevilCoelocephalapion decoloratum1
A Pear-shaped WeevilSayapion segnipes1
Northern Barrens Tiger BeetleCicindela patruela patruela1

Red-headed WoodpeckerMelanerpes erythrocephalus3
Cerulean WarblerSetophaga cerulea2
Eastern Whip-poor-willAntrostomus vociferus2
Long-eared OwlAsio otus2
Worm-eating WarblerHelmitheros vermivorum2
American WoodcockScolopax minor1
Hooded WarblerSetophaga citrina1
Least FlycatcherEmpidonax minimus1
Northern BobwhiteColinus virginianus1

Butterflies and mothsScore
Columbine Dusky WingErynnis lucilius1

Grasshoppers and alliesScore
A Spur-throat GrasshopperMelanoplus foedus2
Showy GrasshopperHesperotettix speciosus2
Blue-legged GrasshopperMelanoplus flavidus1
Club-horned GrasshopperAeropedellus clavatus1
Green-streak GrasshopperHesperotettix viridis1
Grizzly Spur-throat GrasshopperMelanoplus punctulatus1
Handsome GrasshopperSyrbula admirabilis1
Mermiria GrasshopperMermiria bivittata1
Plains Yellow-winged GrasshopperArphia simplex1
Scudder's Short-winged GrasshopperMelanoplus scudderi1
Short-winged GrasshopperDichromorpha viridis1
Speckled Rangeland GrasshopperArphia conspersa1
Spotted-winged GrasshopperOrphulella pelidna1
Stone's LocustMelanoplus stonei1

Leafhoppers and true bugsScore
A LeafhopperCuerna sayi1
A LeafhopperParaphlepsius nebulosus1
A LeafhopperPrairiana angustens1
A LeafhopperFlexamia prairiana1
An Issid PlanthopperBruchomorpha extensa1
Yellow Loosestrife LeafhopperErythroneura carbonata1

Tricolored BatPerimyotis subflavus3
Big Brown BatEptesicus fuscus2
Franklin's Ground SquirrelPoliocitellus franklinii2
Northern Long-eared BatMyotis septentrionalis2
Woodland VoleMicrotus pinetorum2
Little Brown BatMyotis lucifugus1
Silver-haired BatLasionycteris noctivagans1

GophersnakePituophis catenifer3
Gray RatsnakePantherophis spiloides3
Ornate Box TurtleTerrapene ornata3
Timber RattlesnakeCrotalus horridus3
Blanding's TurtleEmydoidea blandingii2
Prairie Ring-necked SnakeDiadophis punctatus arnyi2
Prairie SkinkPlestiodon septentrionalis2
Wood TurtleGlyptemys insculpta2
Butler's GartersnakeThamnophis butleri1
Plains GartersnakeThamnophis radix1
Slender Glass LizardOphisaurus attenuatus1

Please see Section 2. Approach and Methods of the Wildlife Action Plan to learn how this information was developed.

Rare plants

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

Scores: 3 = "significantly associated," 2 = "moderately associated," and 1 = "minimally associated."
Scientific Name Common Name Score
Agrimonia parviflora Swamp Agrimony 2
Aplectrum hyemale Putty Root 1
Asclepias purpurascens Purple Milkweed 2
Besseya bullii Kitten Tails 3
Camassia scilloides Wild Hyacinth 1
Carex swanii Swan Sedge 3
Dasistoma macrophylla Mullein Foxglove 2
Desmodium canescens Hoary Tick-trefoil 3
Desmodium perplexum Perplexed Tick-trefoil 2
Hypericum prolificum Shrubby St. John's-wort 2
Lespedeza violacea Violet Bush Clover 3
Lespedeza virginica Slender Bush Clover 2
Nyssa sylvatica Black Tupelo 1
Prenanthes crepidinea Nodding Rattlesnake-root 1
Quercus muehlenbergii Chinquapin Oak 2
Rhus aromatica Fragrant Sumac 2
Scutellaria ovata ssp. ovata Heart-leaved Skullcap 3
Silene virginica Fire Pink 2
Sisyrinchium angustifolium Pointed Blue-eyed-grass 2
Spiranthes ovalis var. erostellata October Lady's-tresses 2
Thaspium chapmanii Hairy Meadow Parsnip 2
Thaspium trifoliatum var. flavum Purple Meadow Parsnip 2


The following Ecological Landscapes have the best opportunities to manage for Oak Woodland, based on the Ecological Landscapes of Wisconsin Handbook.

Map of the Ecological Landscapes of Wisconsin.

Major (3 on map)
A major opportunity for sustaining the natural community in the Ecological Landscape exists, either because many significant occurrences of the natural community have been recorded in the landscape or major restoration activities are likely to be successful maintaining the community's composition, structure, and ecological function over a longer period of time.

Important (2 on map)
Although the natural community does not occur extensively or commonly in the Ecological Landscape, one to several occurrences do occur and are important in sustaining the community in the state. In some cases, important opportunities may exist because the natural community may be restricted to just one or a few Ecological Landscapes within the state and there may be a lack of opportunities elsewhere.

Present (1 on map)
The natural community occurs in the Ecological Landscape, but better management opportunities appear to exist in other parts of the state.


Wisconsin Wildlife Action Plan graphic

What are conservation actions?

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the WWAP because lack of information can threaten our ability to successfully preserve and care for natural resources.

Threats/issues and conservations actions for natural communities


The following are additional considerations for Oak Woodland in Ecological Landscapes with opportunities for protection, restoration, and/or management. For more information, see the Wildlife Action Plan.

Southeast Glacial Plains

The Southern Unit of the Kettle Moraine State Forest offers some of the best management and restoration opportunities for oak openings and prairies in the upper Midwest. Oak woodland could be incorporated into savanna and prairie restoration projects, thereby providing a fuller representation of the variable conditions formerly characteristic of this region but also providing potentially viable habitat for some of the vulnerable "forest" species in this region. Other potential restoration and management sites occur within the joint TNC-WDNR Mukwonago River Watershed project (Walworth County).

Southwest Savanna

Some of the "pastured but never plowed" oak savanna sites that have been identified in this Ecological Landscape by WDNR Integrated Science Services staff may offer opportunities to restore and manage for savanna and oak woodland types. Additional survey work is needed to clarify the feasibility of initiating projects here.

Western Coulee and Ridges

There are many overgrown oak savanna remnants in this Ecological Landscape and restoration opportunities for both savanna and oak woodland are likely but not yet identified at the site level. Potential examples should be searched for on existing public lands such as Rush Creek Prairie State Natural Area (Crawford County), Fort McCoy Military Reservation (Monroe County), and Lower Chippewa River State Natural Area (Buffalo, Dunn, Trempealeau Counties).

Western Prairie

Some of the Waterfowl Production Areas and Wildlife Areas in this Ecological Landscape (e.g., Oak Ridge Lake Waterfowl Production Area (St. Croix County) may offer restoration potential for this community type.


Oak Woodland Photos

Oak Woodland Photo

White oak woodland along the Mukwonago River, managed with prescribed fire to reduce shrub and sapling cover and encourage native grasses and forbs. Lulu Lake State Natural Area.

Photo by Eric Epstein.

Oak Woodland Photo

Oak woodland with high canopy closure, but the dominant oaks retain distinctive limb architecture and allow more light to reach the ground than in stands with many shade tolerant trees, such as maples.

Photo by Drew Feldkirchner.

Oak Woodland Photo

This white oak-red oak-black oak woodland has been "thinned from below", several prescribed burns have reduced the shade created by the previously dense understory of deciduous shrubs and saplings.

Photo by Eric Epstein.

Oak Woodland Photo

Oak woodland at with sunflower and Silene stellata. Site was restored using presribed fire with burns averaging every two years over a 15 year period.

Photo by Ryan O'Connor.

Oak Woodland Photo

Oak woodland at Trempealeau Mountain SNA with interrupted fern (Osmunda claytoniana).

Photo by Ryan O'Connor.

Note: photos are provided to illustrate various examples of natural community types. A single photograph cannot represent the range of variability inherent in a given community type. Some of these photos explicitly illustrate unusual and distinctive community variants. The community photo galleries are a work in progress that we will expand and improve in the future.

Last revised: Tuesday, August 30, 2022