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.

Target species

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.

MN_wood-thrush_steve-maslowski-usfws
Steve Maslowski USFWS
Wood Thrush
Wood Thrushes are a good benchmark species for the deciduous forest system as they are relatively common but experiencing an overall decline (Breeding Bird Survey data) due to habitat loss and fragmentation. Specifically, the Wood Thrush is a common victim of Brown-headed Cowbird parasitism; cowbirds rely on other birds to incubate and hatch their eggs and raise their young. With the increase in habitat fragmentation in deciduous forests, the cowbird has extended its range dramatically, negatively affecting the productivity of Wood Thrushes. A conservation strategy for the sustainability and enhancement of this species (as well as other species that rely on upland forests) is to create intact, large areas of deciduous forests within the outer region of the metro area, by linking already established systems with suitable habitat corridors.

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.
Copyright  2013 National Audubon Society, Inc

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