Photo by Eric Epstein
- WDNR
State Rank: S4 Global Rank: G4G5 what are these ranks?
In most of Wisconsin the bedrock is buried beneath glacial materials that were deposited during the Pleistocene Ice Age. In glaciated regions, cliffs are associated with certain stretches of the Great Lakes coasts, stream-carved gorges, and the vestigial remnants of ancient, eroded mountain ranges and escarpments. In the "Driftless Area" of southwestern Wisconsin the mantle of glacial drift is absent and erosion has exposed sedimentary bedrock of Paleozoic Age at many locations, most often as a linear series of vertical cliffs.
Technically, a cliff is a geologic feature, not a plant community, however, they are important habitat for a number of plant and animal specialists. They can occur on virtually any rock type. Rock type, exposure, surrounding land cover and other factors create a wide variety of environmental conditions that may influence species composition. The presence or absence of fractures and other features that may hold soil particles and moisture, or the alternation of strata composed of different rock types that have different properties, can affect habitat suitability for plants and animals.
A greater proportion of limestone (dolomite) cliff sites tend to be dry compared to sandstone cliff sites, due to the potential for capillary action in sandstone to hold and slowly transport the water that is essential for plant survival. A soil profile is generally absent, or may occur as localized, usually thin deposits on ledges or in cracks. Dry cliffs may be influenced by aspect, local hydrology, or the proximity of waterbodies. Series of dry cliffs may include stretches or patches that are moist, and these often support additional species. The separation of "dry" from "moist" cliffs can be somewhat artificial, and the totality of the environment should be considered when assessing conservation values and opportunities.
Dry cliff communities occur on many different rock types and vary in species composition. Scattered pines, oaks, cedars, and drought-adapted shrubs such as bush honeysuckle (Diervilla lonicera) and huckleberry (Gaylussacia baccata) often occur on the margins of the exposed rock, or where mineral soil has accumulated on ledges or in fissures. Floristic homogeneity between cliffs is typically rather low, but representative herbs may include the ferns common polypody (Polypodium virginianum), smooth cliff brake (Pellaea glabella), rusty woodsia (Woodsia ilvensis), and northern fragile fern (Cystopteris fragilis), along with wild columbine (Aquilegia canadensis), harebell (Campanula rotundifolia), sand cress (Arabidopsis lyrata), sleepy catchfly (Silene antirrhina), pale corydalis (Capnoides sempervirens), and rock spike-moss (Selaginella rupestris). Dry cliffs are frequently colonized by crustose lichens, which may be the most common inhabitants of bare rock environments for decades or even centuries.
Plant species composition is strongly influenced by the plant community in the immediate vicinity of the cliff, but also includes bare rock specialists, among which are some of Wisconsin's most dramatic examples of disjunct species. An example of a disjunct species is the population of Lapland rose-bay (Rhododendron lapponicum) that grows on a sandstone cliff along the Wisconsin River in the Central Sand Plains. One other population of this species is known from Wisconsin, but the next closest population is on an Adirondack mountaintop in rural New York.
Cliffs are used for denning and roosting by mammals, for nesting and roosting by birds, as hibernacula by herptiles, and also provide suitable conditions for specialized invertebrates. Besides insects, the latter group includes several very rare terrestrial gastropods.
The following Species of Greatest Conservation Need are listed according to their level of association with the Dry Cliff 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 snails | Score | |
|---|---|---|
| Black Striate | Striatura ferrea | 3 |
| Broad-banded Forestsnail | Allogona profunda | 2 |
| Wing Snaggletooth | Gastrocopta procera | 2 |
| Appalachian Pillar | Cochlicopa morseana | 1 |
| Trumpet Vallonia | Vallonia parvula | 1 |
| Birds | Score | |
|---|---|---|
| Peregrine Falcon | Falco peregrinus | 3 |
| Butterflies and moths | Score | |
|---|---|---|
| Columbine Dusky Wing | Erynnis lucilius | 2 |
| Grasshoppers and allies | Score | |
|---|---|---|
| Plains Yellow-winged Grasshopper | Arphia simplex | 1 |
| Speckled Rangeland Grasshopper | Arphia conspersa | 1 |
| Mammals | Score | |
|---|---|---|
| Big Brown Bat | Eptesicus fuscus | 2 |
| Tricolored Bat | Perimyotis subflavus | 2 |
| Reptiles | Score | |
|---|---|---|
| Gophersnake | Pituophis catenifer | 3 |
| Gray Ratsnake | Pantherophis spiloides | 3 |
| Timber Rattlesnake | Crotalus horridus | 3 |
| North American Racer | Coluber constrictor | 2 |
| Prairie Skink | Plestiodon septentrionalis | 1 |
| Western Wormsnake | Carphophis vermis | 1 |
Please see Section 2. Approach and Methods of the Wildlife Action Plan to learn how this information was developed.
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.
| Scientific Name | Common Name | Score |
|---|---|---|
| Anemone multifida var. multifida | Cut-leaved Anemone | 3 |
| Anticlea elegans ssp. glaucus | White Camas | 1 |
| Asplenium pinnatifidum | Pinnatifid Spleenwort | 3 |
| Boechera missouriensis | Missouri Rock-cress | 3 |
| Carex albicans var. albicans | Dry Woods Sedge | 2 |
| Carex backii | Rocky Mountain Sedge | 2 |
| Draba arabisans | Rock Whitlow-grass | 3 |
| Draba cana | Hoary Whitlow-grass | 3 |
| Gymnocarpium jessoense ssp. parvulum | Northern Oak Fern | 3 |
| Huperzia appressa | Mountain Fir Moss | 2 |
| Huperzia porophila | Rock Clubmoss | 1 |
| Minuartia dawsonensis | Rock Stitchwort | 3 |
| Moehringia macrophylla | Large-leaved Sandwort | 3 |
| Pellaea atropurpurea | Purple-stem Cliff-brake | 3 |
| Phemeranthus rugospermus | Prairie Fame-flower | 2 |
| Pseudognaphalium saxicola | Cliff Cudweed | 3 |
| Rhamnus lanceolata var. glabrata | Lanced-leaved Buckthorn | 2 |
| Rhododendron lapponicum | Lapland Azalea | 1 |
| Rhus aromatica | Fragrant Sumac | 1 |
| Salix sericea | Silky Willow | 1 |
| Scutellaria parvula var. parvula | Small Skullcap | 2 |
| Viola sagittata var. ovata | Sand Violet | 1 |
The following Ecological Landscapes have the best opportunities to manage for Dry Cliff, based on the Ecological Landscapes of Wisconsin Handbook.
| Ecological Landscape | Opportunity |
|---|---|
| Central Lake Michigan Coastal | Major |
| Central Sand Plains | Major |
| North Central Forest | Major |
| Northern Lake Michigan Coastal | Major |
| Southeast Glacial Plains | Major |
| Superior Coastal Plain | Major |
| Western Coulee and Ridges | Major |
| Forest Transition | Important |
| Northeast Sands | Important |
| Southwest Savanna | Important |
| Western Prairie | Important |
| Central Sand Hills | Present |
| Northwest Lowlands | Present |
| Southern Lake Michigan Coastal | Present |
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.
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 Dry Cliff in Ecological Landscapes with opportunities for protection, restoration, and/or management. For more information, see the Wildlife Action Plan.
Ecologically important stretches of the dolomitic Niagara Escarpment occur along the east side of the Fox River Valley, north of Lake Winnebago, and in northeastern Brown County, near Red Banks.
Unglaciated exposures of Cambrian sandstones are uncommon but prominent features in this landscape, where they occur in association with eroded landforms such as ridges, mounds, knobs, and pinnacles, some of which are very unusual in the Midwest. Good examples occur at Mill Bluff State Park (Monroe County), in stream gorges and elsewhere on the Black River State Forest (Jackson County), and at Quincy Bluff and Wetlands State Natural Area (Adams County).
Rock outcroppings provide some cliff habitat in places such as the Dells of the Eau Claire River County Park, and Rib Mountain State Park, both in Marathon County.
Bedrock features are scarce and localized here except in the Penokee Range, on the landscape's northern fringe, where there are a number of dry cliffs and "balds" (bedrock glades). There are also a few cliff sites in the eastern part of the Ecological Landscape. Examples can be found on the Iron County Forest (basalt), along the Montreal River (also Iron County) and on the Chequamegon-Nicolet National Forest (e.g., McCaslin Mountain, a quartzite monadnock in Forest County).
Bedrock exposures are uncommon features in the Northeast Sands. They do occur along some of the high gradient streams in the landscape such as the Menominee and Peshtigo, and in association with isolated geologic rock features such as Butler Rock (Oconto County), Thunder Mountain (Marinette County), The Dalles of the Menominee River (Marinette County), and Hagar Mountain (Oconto County).
Cliffs of the dolomitic Niagara Escarpment are striking landscape features on the west side of the Door Peninsula. Examples can be found at Peninsula and Potawatomi State Parks, Ellison Bay Bluff State Natural Area, and Death's Door County Park.
The youngest bedrock exposures in Wisconsin are dolomites of Devonian age, which outcrop as low cliffs and ledges at a few locations near Lake Michigan. Examples may be seen at several locations within the Milwaukee County Park system, such as at Estabrook Park.
Stream cut valleys expose Paleozoic sandstones and dolomites at sites such as Governor Dodge State Park, where the park's trail system permits close examination of the bedrock.
Wave-carved sandstone cliffs are found on rocky headlands along the northern margin of the Bayfield Peninsula, and along the coasts of some of the Apostle Islands (including North Twin Island and Stockton Island Cliffs). Separation of dry from wet cliffs is difficult, and perhaps artificial, as even the driest bedrock associated with the Lake Superior coast may be bathed in fogs or subject to wave spray during storms.
Sandstones and dolomites of Paleozoic age outcrop at many locations, most extensively in the valleys formed by large rivers such as the Mississippi, Wisconsin, Chippewa and Black. The many good examples include Ferry Bluff (Sauk County), the Kickapoo Reserve and Wildcat Mountain State Park (Vernon County), and Maiden Rock Bluff (Pepin County).
Significant bedrock exposures of dolomite and sandstone occur at Kinnickinnic and Willow River State Parks, Apple River Canyon State Natural Area, and at locations in Polk County within the St. Croix-Namekagon National Scenic Riverway.
Click to view a larger version. Please considering donating your photos to the Natural Heritage Conservation Program for educational uses. Photo use
Dry Cliff in the Driftless Area. Levis Mound, Clark County.
Photo by Emmet Judziewicz.
White cedar on fissured dolomite ledges, April 2000.
Photo by Eric Epstein.
Dry, red cedar-capped Dolomite Cliff along the Mississippi River, Pepin County.
Photo by Eric Epstein.
Dry Cliff, Cambrian Sandstone.
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.