Upland Deciduous Hardwood Forest
Throughout Metro: Upland Deciduous Hardwood Forest
Upland hardwood forests historically occurred on sites where wildfires were infrequent. The canopy is usually continuous and dense, and comprised of deciduous trees, most commonly sugar maple, basswood, and red oak. Mature forests usually have several nearly closed layers, including a well-defined forest canopy, sub-canopy, and dense shrub layer. These layers combine to produce continuous cover so that the lower canopy plants found in this habitat are adapted to low light intensity.
Because the tree canopy permits so little light from reaching the forest floor during the summer, maple-basswood forests have a suite of early spring wildflower species that bloom, produce seeds and die back before tree leaves are fully developed. Formerly known as the "Big Woods" there are considerable efforts underway in the western portion of the metro area to protect and restore this upland forest habitat. One of the biggest management challenges is controlling invasive species, particularly non-native earthwormsxxi and European buckthorn.
Birds that thrive in upland forest systems
Sixty-six species breed in metro area deciduous forests, including 12 species of conservation concern: American Woodcock, Black-billed Cuckoo, Eastern Whip-poor-will, Chimney Swift, Northern Flicker, Acadian Flycatcher, Least Flycatcher, Veery, Wood Thrush, Brown Thrasher, Cerulean Warbler, and Louisiana Waterthrush.
The Northern Flickerxxii is a generalist that prefers forest edges, has adapted to human-altered landscapes and is fairly common at backyard bird feeders. However, Breeding Bird Survey data has shown that its population is declining for reasons that are unclear. Some explanations include habitat loss and competition for nest cavities from European Starlings. Whatever the reason, the decline is alarming in that flickers are primary cavity nesters and provide nesting habitat for a wide variety of forest bird species. The loss of the Northern Flicker would likely have a large impact on woodland ecosystems, therefore proactive management is important. A workable equilibrium needs to be established for snag retention in urban areas allowing for some standing dead trees to remain and provide nesting habitat for Northern Flickers and other cavity nesters.
Conservation Actions - Deciduous Upland Forest
- Protect and enhance the remaining large "islands" of upland deciduous forest.
- Restore degraded upland forests and control invasive species.
- The species composition of these "forested islands" should be used as a reference and resource when assessing what native tree and shrub species to plant in landscaped parks and open areas.
- Create habitat corridors of connectivity between the larger patches of upland forest throughout the metro area.
- Retain snags and natural nest cavity sites.