Northern Lowland Forests
The northern wet-mesic forest community type (cedar swamp) is a unique component of the northern Great Lakes states landscape comprising approximately 810,000 hectares. Northern wet-mesic forest communities are typically found in the northern half of Wisconsin. Pre settlement disturbance consisted of small-scale wind and ice damage as well as large scale blowdown every 1000-2000 years and fire every 150-300 years. Northern white cedar, Thuja occidentalis, is the main overstory component of this community and typically forms dense clusters with canopy coverage that may reach 100 percent (Curtis, 1959). This dense foliar canopy tends to exclude other tree species. However, black ash (Fraxinus nigra), balsam fir (Abies balsamea), black spruce (Picea mariana), tamarack (Larix laricina), eastern hemlock (Tsuga canadensis), red maple (Acer rubrum), and yellow birch (Betula alleghaniensis) become established in canopy gaps in this community. Understory flora in this community includes a wide variety of plant groups such as club mosses (e.g. Huperzia lucidula), graminoids (e.g. the sedges Carex disperma and C. trisperma), ferns (Osmunda cinnamomea), ericaceous shrubs (e.g. Ledum groenlandicum), Canada yew (Taxus canadensis), native honeysuckles (Lonicera spp.), and members of the lily (e.g. Maianthemum canadense), composite (e.g. Aster spp.), rose (e.g. Rubus pubescens), and orchid (e.g., Platanthera obtusata and Listera cordata) families. Northern wet-mesic forests are considered regionally significant for a variety of reasons including contributions to deer wintering habitat, wildlife browse, medicinal and ceremonial uses, as well as habitat for rare species of plants.
Original PEL Results
Historically, northern wet-mesic forest made up about 25% or 560,000 acres of the total lowland forest community in northern Wisconsin (Curtis 1959). According to Curtis (1959) typical examples of northern wet-mesic forest can be found at Point Beach State Forest in eastern Wisconsin and within the Northern Highland State Forest of north central Wisconsin. The total understory vascular flora of wet-mesic communities was recorded as 193 species by Curtis (1959). According to Curtis' 1959 study, the three most abundant families in northern wet-mesic forests were the composite family (9.2%), lily family (6.1%), and sedge family (5.7%).
Thirty eight northern wet-mesic forest communities were resurveyed by Matt Bushman and colleagues in 2005. Northern wet-mesic communities have not experienced a significant decline in native species and have actually experienced an increase in abundance of a few important plant species that define the community such as Coptis trifolia (goldthread), Trientalis borealis (starflower), Carex spp. (sedges), and cedar. (continued on next page)