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

Bedrock Glade

State Rank: S3     Global Rank: G2   what are these ranks?


Detailed Community Description from Ecological Landscapes of Wisconsin

General natural community overview

Counties shaded blue have documented occurrences for Bedrock Glade in the Wisconsin Natural Heritage Inventory database.

Bedrock glades are xeric, sparsely vegetated, non-vertical bedrock exposures, with thin, often discontinuous soils. The rock types vary from quartzite (Baraboo Hills, McCaslin Mountain), to basalt (lower St. Croix River valley), to granite (northeastern Wisconsin). The flora can include prairie, savanna, or barrens components, some of them reaching their northern range limits in this community type, as well as bare rock specialists. Tree and shrub cover is usually sparse, and often has structural similarities to a thinly timbered savanna or woodland habitat. Important woody species may include pines (Pinus spp.), oaks (Quercus spp.), hickories (Carya spp.), and cherries (Prunus spp.), along with dogwood (Cornus spp.), hazelnuts (Corylus spp.), prairie willow (Salix humilis), and ericads such as huckleberry (Gaylussacia baccata). Xerophytic pteridophytes such as rusty woodsia (Woodsia ilvensis), northern fragile fern (Salix humilis), and rock spike-moss (Selaginella rupestris) are characteristic plants, as are lichens and mosses. Glades have apparently served as refugia for light- demanding species that are adapted to the more open savanna and prairie conditions that were formerly much more abundant and widespread in parts of Wisconsin. Many uncommon plant species usually associated with these habitats were documented in the glades of the Baraboo Hills.

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 Bedrock Glade 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.

Aquatic and terrestrial snailsScore
Eastern Flat-whorlPlanogyra asteriscus2

Common NighthawkChordeiles minor2
Eastern Whip-poor-willAntrostomus vociferus2
Red-headed WoodpeckerMelanerpes erythrocephalus1

Butterflies and mothsScore
Gorgone Checker SpotChlosyne gorgone1

Grasshoppers and alliesScore
Forest LocustMelanoplus islandicus1
Speckled Rangeland GrasshopperArphia conspersa1

Big Brown BatEptesicus fuscus1
Little Brown BatMyotis lucifugus1

GophersnakePituophis catenifer3
Prairie Ring-necked SnakeDiadophis punctatus arnyi3
Western RibbonsnakeThamnophis proximus3
Prairie SkinkPlestiodon septentrionalis2
Six-lined RacerunnerAspidoscelis sexlineata2
Timber RattlesnakeCrotalus horridus2
Gray RatsnakePantherophis spiloides1

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
Boechera missouriensis Missouri Rock-cress 3
Carex backii Rocky Mountain Sedge 2
Carex merritt-fernaldii Fernald's Sedge 2
Cuscuta coryli Hazel Dodder 1
Lespedeza violacea Violet Bush Clover 3
Lespedeza virginica Slender Bush Clover 3
Moehringia macrophylla Large-leaved Sandwort 3
Opuntia fragilis Brittle Prickly-pear 3
Verbena simplex Narrow-leaved Vervain 2


The following Ecological Landscapes have the best opportunities to manage for Bedrock Glade, 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 Bedrock Glade in Ecological Landscapes with opportunities for protection, restoration, and/or management. For more information, see the Wildlife Action Plan.

Central Sand Hills

Some outcrops of shallow bedrock exist here. Bedrock glade communities exist in places such as the abandoned Badger Army Ammunition Plant. A management plan for state property at this site will likely be developed once transfer from the federal government is completed. This may open some of these areas to visitation, and increased foot traffic, and could impact the plant and lichens assemblages, which are vulnerable to damage. Some of the flat-topped sandstone bedrock features at Mill Bluff State Park (Monroe and Juneau Counties) also support glade vegetation.

Forest Transition

McCaslin Mountain is underlain with quartzite and hosts glade communities that can be managed on national forest lands. The greatest concentrations of glades in this Ecological Landscape are along the Lower St. Croix River, in and around Interstate State Park (Polk County). An example of this community can also be found at Butler's Rock within the Oconto County Forest.

North Central Forest

Much of Northern Wisconsin is underlain by pre-Cambrian granite. "Glades" are uncommon in this heavily forested region but they do occur along several rivers (e.g., the Wolf), on some of the bedrock knobs and mounds in the Chequamegon-Nicolet National Forest, and on the Penokee Range found within the Iron County Forest.

Western Coulee and Ridges

The Baraboo Hills harbors many bedrock glades, with most of them occurring on quartzite. Glade management can be incorporated into parcel-level and landscape-scale management plans for the area on public lands such as Devils Lake State Park and nearby privately owned lands that are managed at least partially for conservation purposes. Examples from the Baraboo Hills include the Caledonia Glades and Devil's Nose, both in Sauk County.

Western Prairie

Some bedrock glade occurrences exist in the lower St. Croix Valley, over basalt bedrock. Osceola Glade, in Polk County, is the best known example.


Bedrock Glade Photos

Bedrock Glade Photo

Bedrock Glade.

Photo by Emmet Judziewicz.

Bedrock Glade Photo

(Basalt) Bedrock Glade, Polk County.

Photo by Eric Epstein.

Bedrock Glade Photo

Igneous rock exposure. Hager Mountain, Oconto County.

Photo by Eric Epstein.

Bedrock Glade Photo

Open bedrock glade with Potentilla tridentata, boreal scrub, and a view of surrounding forested ridges.

Photo by Emmet Judziewicz.

Bedrock Glade Photo

This open glade on quartzite grades into a "pygmy" woodland of stunted bur oak and shagbark hickory in the Baraboo Hills. Sauk County.

Photo by Eric Epstein.

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: Wednesday, June 16, 2021