Northern Dry-mesic Forest

Definition

Detailed Community Description from Ecological Landscapes of Wisconsin

General natural community overview

Northern dry-mesic forests are typically found on irregular glacial topography (e.g., heads-of-outwash, tunnel channel deposits), or in areas with mixed glacial features (e.g., pitted outwash interspersed with remnant moraines). Soils are loamy sands or sands, and less commonly, sandy loams, although some occurrences are in areas where bedrock is close to the surface. Eastern white pine (Pinus alba) and red pine (Pinus resinosa) are typically dominant, sometimes mixed with northern red oak (Quercus rubra), red maple (Acer rubrum), and occasionally, sugar maple (Acer saccharum). Paper birch (Betula papyrifera), trembling aspen (Populus tremuloides), and big-toothed aspen (Populus grandidentata) can also be present. Common understory shrubs include hazelnuts (Corylus spp.) and blueberries (Vaccinium angustifolium and V. myrtilloides), as well as low-growing species such as wintergreen (Gaultheria procumbens) and partridge-berry (Mitchella repens). Among the dominant herbs are wild sarsaparilla (Aralia nudicaulis), Canada mayflower (Maianthemum canadense), and cow-wheat (Melampyrum lineare). Areas of northern dry-mesic forest that were historically dominated by red and white pines (Pinus resinosa and P. strobus) were considered the great "pineries" before the cutover. Today, the extent of red and white pine is greatly decreased, while red maple (Acer rubrum), sugar maple (Acer saccharum), aspen (Populus spp.), and oaks (Quercus spp.) have increased. Historically, fire disturbance of low to moderate intensity and frequency was key to maintaining northern dry-mesic forests.

Three different seral stages are described for northern dry forest, based on the progressive stages of forest regeneration following harvesting or a major natural disturbance from young forest to mid-seral to the attainment of reference conditions as seen in a mature stand. Stands with more than 50 percent aspen by basal area fall into the aspen-birch habitat type. For stands dominated by planted conifers, refer to the conifer plantation type.

• Northern Dry-mesic --late seral: Late-seral (may also be referred to as old, old growth or reference condition) northern dry-mesic forests are dominated by trees 12 inches dbh (diameter at breast height) or more and are usually characterized by a two-staged or uneven age canopy structure. Remnant stands that were not logged during the cutover may have trees commonly over 24 inches dbh, with scattered individuals up to 48 inches dbh or more. Mature trees include white pine (Pinus strobus) and northern red oak (Quercus rubra), and red pine (Pinus resinosa), especially on certain landscapes. Mature red maple (Acer rubrum), paper birch (Betula papyrifera), and aspen (Populus spp.) may be present as well. A subcanopy of shade-tolerant saplings is often present, including white pine, red maple, and occasionally balsam fir (Abies balsamea). The forest is maintained by fire of low to moderate intensity and frequency, or by various silvicultural thinning techniques [e.g., see Landscape Considerations sections of the red pine and oak WDNR Silvicultural Handbook]. Structural diversity is higher with more snags and cavity trees, contributing significant habitat for Species of Greatest Conservation Need (SGCN). Coarse woody debris may also be present if not consumed by periodic fire. Large conifers are an important component for many SGCN, providing thermal cover, nest and den sites, nesting material, as well as snags and coarse woody debris. Even if recognized as late-seral, most trees in managed timber stands won't reach their maximum size and age. Size and age variability are strong contributors to the value of late-seral state forests as habitat for SGCN. Multiple age structures, as well as the snags and coarse woody debris that develop as forests grow older are key for many forest-dependent SGCN. Where managed for ecological values, green tree retention as well as planning for and retaining snags and coarse woody debris is crucial for maintaining and promoting SGCN habitat. Important site- level characteristics that benefit SGCN include large conifers for use as nest trees (e.g. for northern goshawk and red-shouldered hawk), and standing live and dead trees, an abundance of decaying coarse woody debris, and a diverse understory (e.g., for northern flying squirrel).
• Northern Dry-mesic --mid-seral: Mid-seral northern dry-mesic forests are dominated by trees 5-11 inches dbh. Red maple (Acer rubrum), northern red oak (Quercus rubra), or white pine (Pinus strobus) may be dominant, while aspen (Populus spp.) and birch (Betula spp.) may be present in small patches as well, especially in forests specifically managed to promote them. Red pine may be present on certain landscapes. Structural complexity is slightly higher than in young forests with multiple age classes starting to develop, but not as complex as older stands. Snags and coarse woody debris are typically sparse unless intentionally retained by previous management; nonetheless they are important for wildlife habitat. Important site-level characteristics that benefit SGCN include conifer-dominated woodlands adjacent to aquatic habitats like ponds, lakes and streams (e.g., for silver-haired bat), and pockets of open sandy habitat utilized for basking and nesting (e.g., for wood turtle, slender glass lizard, as well as several rare plants).
• Northern Dry-mesic --young seral: Young-seral northern dry-mesic forests are dominated by trees ranging from 0-5 inches in dbh. They typically originate from stand-replacing events such as clear- cutting, catastrophic blow-down, or stand-replacing fire. Species can include red maple (Acer rubrum), red oak (Quercus rubra), white pine (Pinus strobus). Red pine (Pinus resinosa) is characteristic and locally important, but its presence and abundance is dependent on seed source and landscape factors. In addition, aspen and birch can be a significant component. Structural diversity is typically low, as stands are young and usually even-aged. Snags and coarse woody debris may or may not be present depending on stand origin and recent management history. However, widely scattered large trees remaining from natural disturbance or left as reserves in managed forests may be present, and significantly add to the habitat value for SGCN. Important site-level characteristics that benefit SGCN include widely spaced mature trees over a low but dense layer of shrubs or small trees (e.g., for whip-poor-will), young forest adjacent to patches of older forest for foraging, and pockets of open sandy habitat utilized for basking and nesting (e.g., for wood turtle, slender glass lizard, and several rare plants).

In describing these stages, it is recognized that they exist and persist on the landscape due to a marked range of conditions depending on conservation or production goals and the nature and intensity of management. Even the most basic actions of promoting natural regeneration carry the weight of this reality: in an area where the purpose is strictly forest production, the decision to rotate and replant may be relatively straightforward, but on a site managed all or in part for ecological values the prescription and stand rotation is more complex.

Rare animals

Species of Greatest Conservation Need

The following Species of Greatest Conservation Need are listed according to their level of association with the Northern Dry-mesic Forest natural community type, based on the findings in Wisconsin's 2015 Wildlife Action Plan.

Scores: 3 = high association, 2 = moderate association, and 1 = low association. See the key to association scores for complete definitions.

Please see Section 2. Approach and Methods of the Wildlife Action Plan to learn how this information was developed.

Rare plants

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

Landscapes

The following Ecological Landscapes have the best opportunities to manage for Northern Dry-mesic Forest, based on the Ecological Landscapes of Wisconsin Handbook.

Major (3 on map)
A major opportunity for sustaining the natural community in the Ecological Landscape exists, either because many significant occurrences of the natural community have been recorded in the landscape or major restoration activities are likely to be successful maintaining the community's composition, structure, and ecological function over a longer period of time.

Important (2 on map)
Although the natural community does not occur extensively or commonly in the Ecological Landscape, one to several occurrences do occur and are important in sustaining the community in the state. In some cases, important opportunities may exist because the natural community may be restricted to just one or a few Ecological Landscapes within the state and there may be a lack of opportunities elsewhere.

Present (1 on map)
The natural community occurs in the Ecological Landscape, but better management opportunities appear to exist in other parts of the state.

Threats/Actions

What are conservation actions?

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the WWAP because lack of information can threaten our ability to successfully preserve and care for natural resources.

Threats/issues and conservations actions for natural communities

Considerations

The following are additional considerations for Northern Dry-mesic Forest in Ecological Landscapes with opportunities for protection, restoration, and/or management. For more information, see the Wildlife Action Plan.

Central Lake Michigan Coastal, Northern Lake Michigan Coastal, Superior Coastal Plain, Western Coulees and Ridges, Northwest Lowlands The above Ecological Landscapes contain only a small percentage of northern dry-mesic forest, and opportunities for maintenance or restoration are limited. Individual sites may still be important as components of the larger landscape.

Central Sand Plains

Fragmentation is a major issue in this Ecological Landscape. Patch sizes are small and most are farm woodlots. Invasive plants such as garlic mustard and buckthorns are a problem. Older forests in this Ecological Landscape are desirable, especially if they are contained in or linked with blocks of other forest types, such as the oak forests dominant on areas of the Black River State Forest (Jackson Co), Clark County Forest, Jackson County Forest, and Quincy Bluff (Adams County). Alternative management techniques, including prescribed fire, should be used to restore structure and composition.

Forest Transition

Fragmentation is a major issue in this Ecological Landscape, where upland forest is interspersed with farmland, except in the eastern portion of the Ecological Landscape that includes the Menominee Reservation and Chequamegon-Nicolet National Forests. Residential development is further fragmenting and changing this community. Invasives such as buckthorns and Asian honeysuckles are a greater problem here than in the Ecological Landscapes further north. Older northern dry-mesic forests in this Ecological Landscape are desirable, especially if they are contained in or linked with blocks of other forest types

North Central Forest

Fragmentation is an issue in some parts of this Ecological Landscape, especially where residential development and associated road construction are occurring. This Ecological Landscape has opportunities to maintain the northern dry-mesic forest community within the matrix of other forest types in the Ecological Landscape, and to implement other conservation actions (e.g., encourage representation of pine species, older age-classes, and structural diversity) because of the large public ownership. Linkages with other large forested areas should be maintained or enhanced, including connectivity with the Chequamegon-Nicolet and Ottawa National Forests, and the Northern Highland-American Legion State Forest. Depending on landowner objectives, it may be possible to meet many of the needs for early successional habitats on industrial and county forests.

Northeast Sands

This community type is common in the Ecological Landscape. Motorized recreation is increasing and may contribute to soil loss and sedimentation, and facilitate the spread of invasive species. Fragmentation is currently less of an issue in this Ecological Landscape than in other landscapes where this type occurs.

Northern Highland

This Ecological Landscape has a high degree of natural heterogeneity, including complexes of different forest types, wetlands and lakes. Natural ecotones are an important feature. This Ecological Landscape is the best place to maintain or restore large blocks of northern dry-mesic forest. The community type is still widespread within the Ecological Landscape, but due to the lack of natural disturbance combined with deer herbivory, maples are becoming quite competitive. Use adaptive management techniques, including prescribed fire, to restore structure and composition. Opportunities exist to maintain and connect larger blocks in both the Northern Highland-American Legion State Forest and the Chequamegon-Nicolet National Forests. Fragmentation is currently less of an issue in this Ecological Landscape than in other landscapes where this type occurs. Invasives are now becoming a problem, but there is still potential to control smaller infestations if effective measures are taken. Motorized recreation is increasing and may facilitate the spread of invasive species.

Northwest Sands

Northern dry-mesic forests are widespread throughout this Ecological Landscape, and particularly in the northern portion, though much of it is in red pine plantations. Motorized recreation is increasing and may contribute to soil loss and sedimentation, and facilitate the spread of invasive species. Opportunities exist to maintain and connect larger blocks in both the Brule River State Forest and the Chequamegon-Nicolet National Forests.

Photos

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Northern Dry-mesic Forest Photos

Note: photos are provided to illustrate various examples of natural community types. A single photograph cannot represent the range of variability inherent in a given community type. Some of these photos explicitly illustrate unusual and distinctive community variants. The community photo galleries are a work in progress that we will expand and improve in the future.