Fostering Healthy Oak Woodlands

As mature oaks die, younger oaks should take their place. But if the woodland is too dense, young oaks can't get started.

Trees in the North Unit of Cherokee Marsh Conservation Park on the Aspen Trail were thinned by a contractor in February 2026 to connect the open oak woodland habitat found north and south of this area.

Hannah Quinlan, conservation parks supervisor at Madison Parks, commented, “Invasive shrubs (honeysuckle and buckthorn) and mesic tree species such as aspen, black cherry, and hackberry are being removed to promote conditions required to sustain the ecological process of fire and allow continued existence of the oak species found in the canopy.”

From the Wisconsin Department of Natural Resources:

Oak woodlands can be differentiated from oak openings by their higher degree of canopy closure, more dappled light, and more continuous canopy. In contrast, oak openings tend to have significant areas of full sun. Oak woodlands tend to have a groundlayer that thrives in dappled light and usually lacks many of the prairie species present in oak openings. Mature trees in oak woodlands usually lack the short boles and wide-spreading lower limb architecture found in oak openings, but instead have somewhat intermediate growth forms between oak opening and the tall, straight, forest-grown trees found in more closed-canopy forests.

Oak woodlands historically experienced near-annual surface fires. As a result, the subcanopy is very sparse in good quality sites.

Oak woodlands tend to be dominated by members of the white oak group, especially white oak and bur oak. Red oak, black oak, and shagbark hickory may also be present.

Oak woodlands historically experienced near-annual surface fires. As a result, the subcanopy is very sparse in good quality sites, though fire-suppressed sites often contain mesophytic species such sugar maple, red maple, ironwood, hackberry, American elm, and bitternut hickory. The shrub layer is also typically sparse but may include low growing species like low bush honeysuckle (Diervilla lonicera), snowberry (Symphoricarpos albus or S. occidentalis), blueberry (Vaccinium spp.), huckleberry (Gaylussacia baccata), New Jersey tea (Ceanothus americanus), and lead plant (Amorpha canescens).

The groundlayer in oak woodlands is often dominated by a matrix of sedges such as Pennsylvania sedge and savanna running sedge (Carex siccata), sometimes also with a variety of other graminoids that thrive under dappled light conditions such as bottlebrush grass (Elymus hystrix), silky wild-rye (Elymus villosus), and wide-leaved panic grass (Dichanthelium latifolium).

Some forbs typical of high-quality oak woodlands are upland boneset (Eupatorium sessilifolium), prairie alumroot (Heuchera richardsonii), two-flowered Cynthia (Krigia biflora), veiny pea (Lathyrus venosus), pale vetchling (Lathyrus ochroleucus), blunt-leaved sandwort (Moehringia lateriflora), wood betony (Pedicularis canadensis), eastern shooting-star (Primula meadia), yellow-pimpernel (Taenidia integerrima), Culver's-root (Veronicastrum virginicum), Carolina vetch (Vicia caroliniana), and Short's aster (Symphyotrichum shortii).