Native Plant Community Spotlights for Hardwood Hills

Southern Dry-Mesic Oak Woodland

landscape of open field with young oak trees

This bur- and northern pin oak-dominated plant community is common on undulating sand flats, hummocky moraines, and river bluffs throughout the Hardwood Hills. It is typically found on fine sand or sand-gravel soils of south- or west-facing slopes. Historically, fires approaching from the western prairies occurred approximately every 9 years, which kept this community in a fluctuating mosaic between forest and brushland habitat with scattered areas of prairie. The development of modern fire suppression and conversion to agriculture has led to the loss of this mosaic of oak openings. The canopy of this community often contains open-grown northern pin oak and bur oak trees with spreading branches and a dense shrub layer of prickly ash, chokecherry, American hazelnut, gray dogwood, prickly gooseberry, and downy arrowwood.

To keep this native plant community healthy, consider doing management activities that mimic the frequent mild to severe fires that once shaped this ecosystem. You might consider a strategy of creating openings to maintain an interrupted canopy and perform prescribed burning in these openings when possible.

Learn more about Southern Dry-Mesic Oak Woodland

Southern Dry Savanna

open forest with oak trees with a open prairie.

 

This unique native plant community is considered "critically imperiled" based on its rarity and threats facing the remaining examples. These savannas formed in dry areas where streams, lakes, and steep hillsides protected them from the intense prairie fires. Under these conditions fires occurred frequently enough to prevent trees and shrubs from dominating, but allowed fire-tolerant tree species to become established. These trees occur as dispersed individuals with an open-grown form (wide-spreading branches) or in scattered small clumps with total tree cover between 25 and 50 percent. Bur oak is the most common tree in these savannas but northern pin oak is also usually present. The species composition of the ground layer depends on soils and topography, however little bluestem and porcupine grass usually dominate, and big bluestem and Indian grass are usually present and often common. Woodland forbs and grasses are also often present.

Because of the rarity of this native plant community, efforts should be made to keep it as healthy and resilient as possible. You can help protect this unique ecosystem by monitoring the understory and edges of your savanna for invasive shrubs such as buckthorn, honeysuckle, multiflora rose, and Russian olive—and taking fast action to control them through applying herbicide, removing by hand or other means, and prescribed fire.

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Central Mesic Hardwood Forest

heaverly forested area with supar maples

This native plant community is found almost exclusively in the Hardwood Hills where the soils are well-drained and loamy on rolling to hummocky moraines. The canopy of this plant community is typically dominated by sugar maple and basswood, often with paper birch and less frequently with quaking aspen, northern red oak, bur oak, American elm, or ironwood. Plants growing in the ground layer vary and species richness is considerably lower than in other central and southern mesic hardwood forest communities in Minnesota. Important species include large-flowered bellwort and Pennsylvania sedge.

Catastrophic disturbances were historically rare. More commonly, smaller disturbances that created smaller gaps resulted in a mix of shrub, sub-canopy, and canopy layers. Tailoring your firewood harvesting strategy to create small gaps (single trees or small clusters) in your woods will allow some of the abundant maple saplings to develop and give your forest more vertical diversity. If you want to add more diverse species to your forest, consider developing additional medium to large gaps up to an acre that may encourage oaks and birches to grow. Similar to the effects of fire in the past, either strategy helps create diverse age groups among your trees, which creates better wildlife habitat and helps your woods resist environmental stress.

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Lakeshore

lakeshore with broad-leaves cattails and grasses.

Lakeshore is prevalent in west-central Minnesota. Shores may be sandy or muddy and could contain a variety of terrestrial and aquatic plants depending on the season and current water level. Just above the normal water level you may find shrubs and forbs such as sandbar willow, spotted touch-me-not, and swamp milkweed. Below the normal water level you may find broad-leaved cattail, an assortment of sedges and rushes, and floating plants like water lilies and pondweeds.

A variety of ecosystems, from upland forest to lowland swamp, surround these lakes. While proper management along the shore can protect it from wave damage, how land is managed near shorelines also plays a key role in erosion control. Forests help filter runoff and hold soil in place, whereas agriculture and lawns can add soil, fertilizer, and pesticides to the runoff that flows into lakes. It is important to consider the impacts that all land use and management activities have on your lake, even beyond the shores.

Learn more about restoring your shore

Habitat spotlight: Mature Hardwood Forests

hardwood forest in fall colorsMature hardwood forest provide important habitat for many wildlife species in your region, especially for birds such as red-shouldered hawks and multiple species of warblers and wrens. Least weasel, tree frogs, spring peepers, wood frogs, and garter snakes all also depend on mature hardwood forests. This habitat has declined by over 60 percent in the last 100 years as a result of conversion to agriculture. Today it is under additional pressure from land use conversion, fragmentation, and residential development. Consider your role in maintaining this habitat on the landscape through carefully managing your land to support these resident and migratory species that rely on mature hardwood forests.

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