Abstract for CM014

Eastern North American Temperate Hardwood - Conifer Forest
Forêts mixtes de la zone tempérée de l’Est de l'Amérique du Nord

CM014 describes the upland temperate forests of southeastern Manitoba, the upper Great Lakes region of Ontario, the southern Precambrian Shield areas of west-central Quebec and the Appalachian region of eastern Quebec. Forest canopies are primarily a mixture of cold-deciduous broad-leaved and evergreen coniferous species. Anthropogenic disturbance is a dominant factor in determining current forest composition and dynamics. Windthrow, ice loading and insect infestations are the most widespread forms of natural disturbance; fire is a factor in the western portion of the range. Dominant tree species include balsam fir (Abies balsamea), red maple (Acer rubrum), paper birch (Betula papyrifera), yellow birch (B. alleghaniensis), sugar maple (A. saccharum) and white spruce (Picea glauca). Eastern white cedar (Thuja occidentalis) is a common companion species throughout the range. Eastern white pine (Pinus strobus), red pine (P. resinosa) and northern red oak (Quercus rubra) are common canopy associates in the Great Lakes and western Quebec portions of the range; red spruce (Picea rubens) is an important secondary canopy constituent in the eastern part of the range. American beech (Fagus grandifolia) and eastern hemlock (Tsuga canadensis) are occasional in the southern part of the range east of the Great Lakes. Depending on overstory and site conditions, understory shrub and herb layers vary from dense to sparse. In addition to regenerating balsam fir, understories are generally rich in cold-deciduous broad-leaved shrubs, perennial herbs and, east of the Great Lakes, regenerating maples and yellow birch. Mountain maple (Acer spicatum), beaked hazelnut (Corylus cornuta), Canada fly-honeysuckle (Lonicera canadensis) and northern bush-honeysuckle (Diervilla lonicera) are common throughout the range. Typical herb/dwarf shrub species include bunchberry (Cornus canadensis), wild lily-of-the-valley (Maianthemum canadense), northern starflower (Lysimachia borealis), yellow clintonia (Clintonia borealis), wild sarsaparilla (Aralia nudicaulis) and rose twisted-stalk (Streptopus lanceolatus). Vernal ephemeral forbs like Carolina spring beauty (Claytonia caroliniana) and yellow trout lily (Erythronium americanum) are characteristic of maple-dominated stands east of the Great Lakes.

CM014 occurs at the northern extent of the mostly humid, continental cool temperate climate of eastern Canada, which is characterized by cool snowy winters and warm humid summers. Mean annual temperatures vary from 1°C to >5°C. Mean annual precipitation increases from (approximately) 600 mm near the Manitoba border to >1100 mm in some areas of eastern Ontario and Quebec. Rainfall significantly exceeds snowfall. Regional geologic and topographic features of the Shield and Appalachian physiographic regions produce an array of local site conditions. All parts of the range experienced late Pleistocene glaciation; soils are mostly Podzols, Brunisols and Luvisols developed in glacial surficial materials.

Three subtypes distinguish regional variation within this Macrogroup. Subtype CM014a [Subhumid Eastern Temperate Hardwood – Conifer Forest] describes temperate forests west of Lake Superior that occur in a generally drier climate with little or no presence of sugar maple, yellow birch or eastern hemlock. CM014b [Humid Eastern Temperate Hardwood – Conifer Forest] describes maple – yellow birch – balsam fir dominated forests east of the Great Lakes that contain significant presence of eastern white pine, red pine and northern red oak. CM014c [Very Humid Eastern Temperate Hardwood – Conifer Forest] describes maple – yellow birch – balsam fir dominated forests in the maritime-influenced climate of the eastern portion of the range, containing greater abundance of balsam fir and significant red spruce content.