NATURAL COMMUNITY

Dry-mesic Southern Forest

Terrestrial Class Forest Group

An oak-dominated woodland community found on well-drained soils across parts of Southeast Michigan.

Overview

Dry-mesic southern forest is a fire-dependent, oak or oak-hickory forest type on generally dry-mesic sites found south of the climatic tension zone in southern Lower Michigan. Frequent fires maintain semi-open conditions, promoting oak regeneration and ground and shrub layer diversity.

County distribution

County map showing distribution of Dry-mesic Southern Forest

Landscape Context

This natural community occurs principally on glacial outwash, coarse-textured moraines, sandy glacial lakeplains, kettle-kame topography, and sand dunes.

Soils

Soils are typically sandy loam or loam and slightly acid to neutral in pH.

Natural Processes

Fire, windthrow, and insect outbreaks and pathogens associated with oak defoliation and decline are the prevalent natural disturbance factors influencing dry-mesic southern forest. Historically, frequent, low-intensity surface fires generated conditions suitable for sustaining advanced oak regeneration and helped keep oak pathogens and invertebrate acorn predators at low levels. Tree density in circa 1800 oak forests was likely lower than that observed today under conditions of fire suppression, and helped limit root-grafting and the spread of several oak pathogens. Frequent small-scale wind disturbance or gap-phase dynamics allows for growth of suppressed oak saplings and canopy ascension of understory oaks. Prolonged periods of fire suppression in oak openings can result in the succession to closed-canopy dry-mesic southern forest and likely accounts for the existence of many oak forests observed today.

Vegetation

The canopy layer generally is dominated or codominated by white oak ( Quercus alba ) and black oak ( Quercus velutina ), with white oak being the more frequent dominant. Red oak ( Q. rubra ) can occur as a canopy codominant, especially where soils and topographic position favor less droughty conditions such as north- to east-facing slopes and footslopes. Hickories such as pignut hickory ( Carya glabra ) , shagbark hickory ( C. ovata ), and bitternut hickory ( C. cordiformis ) are often canopy codominants. Prevalent canopy associates may include red maple ( Acer rubrum ), white ash ( Fraxinus americana ), black cherry ( Prunus serotina ), Hill's oak ( Quercus ellipsoidalis ), basswood ( Tilia americana ), and sassafras ( Sassafras albidum ). Prevalent species of the subcanopy include red maple, hickories, alternate-leaved dogwood ( Cornus alternifolia ), flowering dogwood ( C. florida ), ironwood ( Ostrya virginiana ), cherries ( Prunus spp.), and sassafras. Characteristic shrubs include serviceberries ( Amelanchier spp.) , witch hazel ( Hamamelis virginiana ), and choke cherry ( Prunus virginiana ). In fire-suppressed systems, mesophytic trees and shrubs are often dominant in the subcanopy and shrub layers. Typical herbaceous species include doll's eyes ( Actaea pachypoda ), hog peanut ( Amphicarpaea bracteata ), jack-in-the-pulpit ( Arisaema triphyllum ), bearded shorthusk ( Brachyelytrum erectum ), hairy woodland brome ( Bromus pubescens ), white bear sedge ( Carex albursina ), rosy sedge ( C. rosea ), enchanter's nightshade ( Circaea canadensis ), spotted coral-root ( Corallorhiza maculata ), pointed-leaf tick-trefoil ( Hylodesmum glutinosum ), naked-flower tick-trefoil ( H. nudiflorum ), fragrant bedstraw ( Galium triflorum ), black snakeroot ( Sanicula marilandica ), bristly greenbrier ( Smilax hispida ), large-flowered bellwort ( Uvularia grandiflora ), and downy yellow violet ( Viola pubescens ).

Biodiversity Management Considerations

Fire is the single most significant factor in preserving oak ecosystems. The use of prescribed fire is an imperative management tool for promoting oak regeneration, deterring the succession of shade-tolerant species, and reducing the encroachment by invasive shrubs such as honeysuckles and autumn olive. Fire management should be orchestrated in conjunction with the management of fire-dependent communities such as oak barrens, dry sand prairie, prairie fen, and coastal plain marsh. Many current dry-mesic southern forests are degraded oak openings that have been long deprived of fire. Open canopy conditions can be restored by mechanical thinning or girdling. Restored sites will need to be maintained by periodic prescribed fire and may require investment in native plant seeding where seed and plant banks are inadequate. Herbicide application to stumps is likely necessary where woody invasive species or red maple are well established. Monitoring and control efforts to detect and remove invasive species are critical to the long-term viability of dry southern forest. Invasive species that threaten the diversity and community structure include garlic mustard ( Alliaria petiolata ), black swallow-wort ( Vincetoxicum nigrum ), white swallow-wort ( V . rossicum ), Oriental bittersweet ( Celastrus orbiculatus ), common buckthorn ( Rhamnus cathartica ), autumn olive ( Elaeagnus umbellata ), Eurasian honeysuckles ( Lonicera morrowii , L. japonica , L. maackii , L. tatarica , L . x bella , and L. xylosteum ), multiflora rose ( Rosa multiflora ), and Norway maple ( Acer platanoides ).

Variation

Red oak can occur as a codominant on moister soils. Toward the transition zone, white pine ( Pinus strobus ) becomes a canopy associate.

Associated plants

Graminoids
autumn bent Agrostis perennans
Graminoids
long-awned wood grass Brachyelytrum erectum
Graminoids
Canada brome Bromus pubescens
Graminoids
sedges Carex albursina, cephalophora, communis, digitalis, pensylvanica, rosea
Graminoids
poverty grass Danthonia spicata
Graminoids
panic grasses Dichanthelium
Graminoids
bottlebrush grass Elymus hystrix
Graminoids
nodding fescue Festuca subverticillata
Graminoids
cut-leaved rice-grass Oryzopsis asperifolia
Forbs
doll’s eyes Actaea pachypoda
Forbs
tall agrimony Agrimonia gryposepala
Forbs
hog-peanut Amphicarpaea bracteata
Forbs
wild columbine Aquilegia canadensis Species guide available Wild Columbine
Forbs
wild sarsaparilla Aralia nudicaulis
Forbs
poke milkweed Asclepias exaltata
Forbs
false foxglove Aureolaria
Forbs
enchanter’s-nightshade Circaea canadensis
Forbs
wild yam Dioscorea villosa
Forbs
large-leaved aster Eurybia macrophylla
Forbs
bedstraws Galium circaezans, triflorum
Forbs
wild geranium Geranium maculatum Species guide available Wild Geranium
Forbs
round-leaved hepatica Hepatica americana
Forbs
pointed-leaf tick-trefoil Hylodesmum glutinosum
Forbs
naked-flower tick-trefoil Hylodesmum nudiflorum
Forbs
Canada mayflower Maianthemum canadense
Forbs
false spikenard Maianthemum racemosum
Forbs
hairy sweet cicely Osmorhiza claytonii
Forbs
jumpseed Persicaria virginiana
Forbs
lopseed Phryma leptostachya
Forbs
may apple Podophyllum peltatum
Forbs
large-leaved shinleaf Pyrola elliptica
Forbs
black snakeroots Sanicula
Forbs
bluestem goldenrod Solidago caesia
Forbs
elm-leaved goldenrod Solidago ulmifolia
Forbs
early meadow-rue Thalictrum dioicum
Forbs
rue-anemone Thalictrum thalictroides
Forbs
common trillium Trillium grandiflorum
Forbs
large-flowered bellwort Uvularia grandiflora
Forbs
merrybells Uvularia sessilifolia
Forbs
downy yellow violet Viola pubescens
Ferns
rattlesnake fern Botrypus virginianus
Ferns
bracken fern Pteridium aquilinum
Woody Vines
Virginia creeper Parthenocissus quinquefolia
Woody Vines
bristly greenbrier Smilax hispida
Woody Vines
poison-ivy Toxicodendron radicans
Woody Vines
summer grape Vitis aestivalis
Woody Vines
riverbank grape Vitis riparia
Shrubs
serviceberries Amelanchier
Shrubs
gray dogwood Cornus foemina
Shrubs
American hazelnut Corylus americana
Shrubs
wintergreen Gaultheria procumbens
Shrubs
huckleberry Gaylussacia baccata
Shrubs
witch-hazel Hamamelis virginiana
Shrubs
choke cherry Prunus virginiana
Shrubs
prickly gooseberry Ribes cynosbati
Shrubs
common blackberry Rubus allegheniensis
Shrubs
black raspberry Rubus occidentalis
Shrubs
wild red raspberry Rubus strigosus
Shrubs
low sweet blueberry Vaccinium angustifolium
Shrubs
Canada blueberry Vaccinium myrtilloides
Shrubs
hillside blueberry Vaccinium pallidum
Shrubs
maple-leaved arrow-wood Viburnum acerifolium
Trees
red maple Acer rubrum
Trees
juneberry Amelanchier arborea
Trees
bitternut hickory Carya cordiformis
Trees
pignut hickory Carya glabra
Trees
shagbark hickory Carya ovata
Trees
alternate-leaved dogwood Cornus alternifolia
Trees
flowering dogwood Cornus florida
Trees
white ash Fraxinus americana
Trees
ironwood Ostrya virginiana
Trees
black cherry Prunus serotina
Trees
white oak Quercus alba
Trees
northern pin oak Quercus ellipsoidalis
Trees
red oak Quercus rubra
Trees
black oak Quercus velutina
Trees
sassafras Sassafras albidum
Trees
basswood Tilia americana

MNFI via Ecological Commons