Ecological Landscapes are 16 areas of Wisconsin with different ecological attributes and management opportunities. They can be used to identify the best areas of the state to manage for different natural communities, key habitats, aquatic features and native plants and animals from an ecosystem management perspective. See below for more information about forest types in Northwest Wisconsin. You can find additional information in the DNR's Ecological Landscapes Handbook.
Forests of Northwest Wisconsin
Four main types of forests are common in the major ecological landscapes of Northwest Wisconsin. These are the North Central Forest, the Superior Coastal Plain, the Northwest Sands, and the Northwest Lowlands. Common across the region is the fact that the forests of today are significantly different than those that existed prior to European settlement.
North Central Forests
The forest once common to the North Central Forest landscape was dominated by hemlock, sugar maple, and yellow birch, with scattered white pine and stands of red pine. Other more minor species included aspen, red maple, white ash, basswood, and red oak. Lowland forest areas were likely comprised of either black ash or black spruce, and tamarack.
The intensive management beginning with the Cutover drastically altered the historical forest. Extensive clear-cutting has perpetuated the aspen-dominated forests that developed following the Cutover. Aspen is an early-successional species that dominates after intense disturbances, but is typically replaced by more shade-tolerant species unless clear-cut again at maturity (40-60 years).
Where clear-cutting or other major disturbance does not occur, aspen forests transition to a mix of conifers (often white pine, balsam fir, and white spruce) and hardwoods (such as red maple and sugar maple). The current historically record-high deer populations have resulted in extensive browsing of some tree seedlings, preventing their recovery and return to being a significant component of the forest. On some sites, a restoration approach to forestry can provide an alternative for bringing back a forest more closely characteristic of the historic forest. Less intensive harvesting of mature aspen, coupled with under-planting of conifers is one such approach.
On the coastal plain which follows the Lake Superior shoreline from Duluth to the Penokee Hills at Hurley with a width from 1 to 24 miles, the pre-settlement forest is described as the “Wisconsin Boreal Forest”– a combination of boreal forest and the hemlock-hardwood species of the North Central forest. It was dominated by balsam fir, white spruce, white birch, aspen, hemlock, sugar maple, yellow birch, white pine, and red pine.
After the Cutover, early-successional sun-loving species such as aspen, white birch, red pine, and red oak have come to dominate much of this landscape. In general, conifers such as white pine, white cedar, white spruce, and hemlock have become much less abundant.
Short-rotation even-aged management consisting of large-acreage clear-cuts every 40 to 60 years has become common. Such a system is highly efficient at regenerating aspen and producing pulpwood volume, but essentially eliminates the growth and development of the long-lived conifers and hardwoods. As in the North Central Forest, some sites offer opportunities for practicing a restoration approach to forestry for landowners interested in bringing back a forest more closely characteristic of the historic forest.
The Northwest Sands landscape describes an area in northwest Wisconsin sometimes called a “barrens” because of the dry soils and sparse vegetation relative to other areas in the region. The Northwest Sands run from northern Bayfield County southwest through Burnett County and into Minnesota. Pre-settlement vegetation was adapted to the dry, nutrient-poor soils and frequent fires, which occurred every 10-20 years in the southern region and every 40-60 years in the northern region of the Northwest Sands. In the southern and central parts of the Northwest Sands, jack pine was the dominant tree species, while the northern region contained extensive areas of red and white pine savanna due to less frequent, but more intense fire.
In some micro-climates where soil fertility was higher and/or fire had not burned recently, maple/birch forests were present (containing red maple, oaks, aspen, and birch). Current forests in the Northwest Sands differ significantly from pre-settlement conditions. Fire suppression has resulted in an increase in hardwood species such as red oak, red maple, birch, and aspen. Much of the Northwest Sands landscape is planted in red and jack pine plantations. White pine has declined substantially following the Cutover, primarily due to the lack of a seed source. Less than 10,000 acres of land in the Northwest Sands approximates the open barrens that dominated the area before settlement. Due to the natural disturbance regime and the conditions necessary for recovering and perpetuating the vegetation more historically characteristic of the area, intensive management such as clear-cutting and burning are actually important management tools used for restorative approaches to forestry in the Northwest Sands.
The Northwest Lowlands landscape forms a triangular wedge bounded on the north by the Superior Coastal Plain and the south and east by the Northwest Sands. The pre-settlement forests of this area were comprised of mostly paper birch, fir, sugar maple, aspen, and white spruce, with some pine on the ridges. In wetter areas that dominate portions of this landscape, forests of black spruce and tamarack were common, along with some swamps dominated by white cedar and black ash. The Northwest Lowlands landscape occupies a major drainage divide, containing the headwaters of many streams flowing north towards Lake Superior or south toward the St. Croix River system.
The current forests consist mainly of aspen, paper birch, sugar maple, basswood, spruce, and fir, with some small amounts of white and red pine, and red oak also present. Aspen is much more abundant than before the Cutover and spruce and white pine less abundant. Unlike many other regions in Wisconsin, the Northwest Lowlands still have extensive blocks of largely unfragmented forests providing habitat for species needing continuous forest. Landowners in this region can work to restore the pine and spruce component that has been reduced in this landscape.