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

Southern Mesic Forest

State Rank: S3     Global Rank: G3?   what are these ranks?


Detailed Community Description from Ecological Landscapes of Wisconsin

General natural community overview

Counties shaded blue have documented occurrences for Southern Mesic Forest in the Wisconsin Natural Heritage Inventory database.

This upland forest community occurs on rich, well-drained loamy soils, mostly on glacial till plains or loess-capped sites south of the tension zone. The dominant tree species is sugar maple (Acer saccharum), but American basswood (Tilia americana), and near Lake Michigan, American beech (Fagus grandifolia) may be co-dominant. Many other trees are found in these forests, including those of the walnut family, ironwood (Carpinus caroliniana), northern red oak (Quercus rubra), red maple (Acer rubrum), white ash (Fraxinus americana), and slippery elm (Ulmus rubra). The understory is typically open, or sometimes brushy with species of gooseberry (Ribes spp.) on sites with a history of grazing, and supports fine spring ephemeral displays. Characteristic herbs are spring-beauty (Claytonia virginica), trout-lilies (Erythronium spp.), trilliums (Trillium spp.), violets (Viola spp.), bloodroot (Sanguinaria canadensis), blue cohosh (Caulophyllum thalictroides), may-apple (Podophyllum peltatum), and Virginia waterleaf (Hydrophyllum virginianum).

Historically, southern mesic forests were quite common throughout southern Wisconsin. For example, forests dominated by sugar maple or beech occupied 41% of the Southern Lake Michigan Coastal, 25% of the Southeast Glacial Plains, and 18% of the Western Coulees and Ridges Ecological Landscapes (Finley 1976). Most of these forests were cleared for agriculture because the soils are very fertile.

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 Southern Mesic Forest 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.

Four-toed SalamanderHemidactylium scutatum3
Pickerel FrogLithobates palustris1

Ants, wasps, and beesScore
Confusing Bumble BeeBombus perplexus1
Indiscriminate Cuckoo Bumble BeeBombus insularis1
Rusty-patched Bumble BeeBombus affinis1
Yellowbanded Bumble BeeBombus terricola1

Aquatic and terrestrial snailsScore
Appalachian PillarCochlicopa morseana3
Brilliant GranuleGuppya sterkii3
Broad-banded ForestsnailAllogona profunda3
Cherrystone DropHendersonia occulta3
Ribbed StriateStriatura exigua3
Black StriateStriatura ferrea2
Bright GlyphGlyphyalinia wheatleyi2
Bronze PineconeStrobilops aeneus2
Hubricht's VertigoVertigo hubrichti2
Sculpted GlyphGlyphyalinia rhoadsi2
Dentate SupercoilParavitrea multidentata1

Acadian FlycatcherEmpidonax virescens3
Hooded WarblerSetophaga citrina3
Kentucky WarblerGeothlypis formosa3
Cerulean WarblerSetophaga cerulea2
Long-eared OwlAsio otus2
American WoodcockScolopax minor1
Eastern Whip-poor-willAntrostomus vociferus1
Least FlycatcherEmpidonax minimus1
Red-shouldered HawkButeo lineatus1
Worm-eating WarblerHelmitheros vermivorum1
Yellow-breasted ChatIcteria virens1

Butterflies and mothsScore
A Noctuid MothBagisara gulnare1
Gray CopperLycaena dione1

Grasshoppers and alliesScore
Bog ConeheadNeoconocephalus lyristes1
Short-winged GrasshopperDichromorpha viridis1
Spotted-winged GrasshopperOrphulella pelidna1

Eastern PipistrellePerimyotis subflavus2
Little Brown BatMyotis lucifugus2
Northern Long-eared BatMyotis septentrionalis2
Water ShrewSorex palustris2
Woodland Jumping MouseNapaeozapus insignis2
Big Brown BatEptesicus fuscus1
Northern Flying SquirrelGlaucomys sabrinus1
Silver-haired BatLasionycteris noctivagans1
Woodland VoleMicrotus pinetorum1

Gray RatsnakePantherophis spiloides3
Timber RattlesnakeCrotalus horridus3
Blanding's TurtleEmydoidea blandingii2
GophersnakePituophis catenifer2
Ornate Box TurtleTerrapene ornata2
Wood TurtleGlyptemys insculpta2
Western WormsnakeCarphophis vermis1

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
Adoxa moschatellina Muskroot 2
Aplectrum hyemale Putty Root 3
Arnoglossum reniforme Great Indian-plantain 3
Astragalus neglectus Cooper's Milkvetch 2
Boechera dentata Short's Rock-cress 2
Carex backii Rocky Mountain Sedge 2
Carex careyana Carey's Sedge 3
Carex digitalis var. digitalis Slender Wood Sedge 3
Carex formosa Handsome Sedge 3
Carex gracilescens Slender Sedge 3
Carex media Intermediate Sedge 3
Carex prasina Drooping Sedge 3
Carex swanii Swan Sedge 2
Desmodium perplexum Perplexed Tick-trefoil 1
Diarrhena obovata Ovate Beak Grass 2
Erigenia bulbosa Harbinger-of-spring 3
Eurybia furcata Forked Aster 3
Fraxinus quadrangulata Blue Ash 3
Gymnocladus dioicus Kentucky Coffee-tree 2
Homalosorus pycnocarpos Glade Fern 3
Hydrastis canadensis Golden-seal 3
Hydrophyllum appendiculatum Great Water-leaf 3
Jeffersonia diphylla Twinleaf 3
Juglans cinerea Butternut 3
Melica nitens Three-flowered Melic Grass 2
Nyssa sylvatica Black Tupelo 2
Phegopteris hexagonoptera Broad Beech Fern 3
Plantago cordata Heart-leaved Plantain 3
Poa sylvestris Woodland Bluegrass 3
Poa wolfii Wolf's Bluegrass 2
Polystichum acrostichoides Christmas Fern 3
Prenanthes crepidinea Nodding Rattlesnake-root 1
Primula fassettii Jeweled Shooting Star 2
Quercus muehlenbergii Chinquapin Oak 1
Solidago caesia Bluestem Goldenrod 3
Trillium nivale Snow Trillium 3
Triphora trianthophora Nodding Pogonia 3
Viburnum prunifolium Smooth Black-haw 3


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

Central Lake Michigan Coastal

Large blocks of this type should be maintained where present along the lower Wolf River. Sites in the southeast where beech is a co-dominant should also be maintained.

Central Sand Plains

This type should be embedded within large blocks of other forest types that are more common in this Ecological Landscape

Southeast Glacial Plains

Past land clearing for agriculture has reduced and fragmented this community type, resulting in edge effects and isolation. Forests are being cleared for development as urban areas expand and residents seek solitude by developing housing in remaining rural areas. Larger blocks of this type should be maintained where present (e.g., North Unit Kettle Moraine, where the type is mixed with dry-mesic forests). A component of beech and oak species should also be maintained within this type where appropriate and feasible. This community type is often found in association with outcrops of the Niagara Escarpment. The Niagara Escarpment is a regionally significant repository of highly specialized rare species (e.g., land snails). It supports microhabitats that do not occur elsewhere, contributing to occurrences of embedded localized community types such as moist cliff. More survey work is needed to document the variability of these communities (i.e., to differentiate between sites in North Kettle Moraine and on the Niagara Escarpment). Millhome Woods in southern Manitowoc County is another large site that supports southern mesic forest.

Southern Lake Michigan Coastal

This type has been severely reduced from its past extent. Manage this type as a complex with other forest types along river corridors (e.g., Root River).

Southwest Savanna

Operations on steep slopes can cause rutting, soil erosion, and contribute to hydrologic changes such as overland flow.

Western Coulee and Ridges

Operations on steep slopes can cause rutting, soil erosion, and contribute to hydrologic changes such as overland flow. Large blocks of this type should be maintained where present (e.g., Baraboo Hills, Lower and Middle Kickapoo Watershed, Lower Wisconsin Riverway). Sauk, Richland, and Vernon counties contain the larger blocks. Significant areas (due to species composition) include those south of the Wisconsin River in Grant County, where dolomite bedrock occurs. Floristically these forests are often very rich and support species not common in the rest of the Ecological Landscapes.

Western Prairie

Urban expansion is occurring within the Western Prairie Ecological Landscape, and housing developments can directly impact this community. Historically this community type occupied a large portion of the eastern part of the Ecological Landscape. Existing forests are scattered; additional fragmentation of existing forests along river corridors should be avoided.


Southern Mesic Forest Photos

Southern Mesic Forest Photo

Remnant mesic hardwood forest in Milwaukee County dominated by large oaks, maples, American basswood, and American beech. Few such remnants persist in SE WI.

Photo by Emmet Judziewicz.

Southern Mesic Forest Photo

Floristically rich sugar maple-basswood forest on an alluvial terrace just above the floodplain of the Black River supports not only a diverse herbaceous layer, but several rare animals as well.

Photo by Eric Epstein.

Southern Mesic Forest Photo

Floristically rich southern mesic forest dominated by sugar maple, basswood, and red oak occupies this moist cove opening to the Kickapoo River. Wilton Hemlocks.

Photo by Eric Epstein.

Southern Mesic Forest Photo

Southern mesic forest with large sugar maple over a carpet of spring ephemerals.

Photo by Ryan O'Connor.

Southern Mesic Forest Photo

S mesic forests are characterized by a rich groundlayer of wildflowers, including large-flowered trillium, false rue-anemone, bellwort, wild leek.

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: Wednesday, June 16, 2021