Name:
Acer saccharum - Betula alleghaniensis - Fagus grandifolia / Viburnum lantanoides Forest
Reference:
Eastern Ecology Working Group of...
Description:
This association, known commonly as "northern hardwood forest," is a widespread matrix forest in central New England, and at lower elevations in northern New England. This forest occurs most commonly on acid (pH 5-6), moderate to well-drained tills at elevations generally below 2500 feet. In northern New England, they cover extensive mid-elevation ridges; elsewhere, slope settings are common. The closed-canopy forest has sparse to moderate shrub and herb cover, and may have local carpets of tree seedlings in the ground vegetation. Bryoids are a minor component of the forest floor. On some rocky, higher-elevation sites, dense ferns and other herbs may form a lush understory (the "fern-glade variant"). The canopy is dominated by Acer saccharum, Fagus grandifolia, and Betula alleghaniensis with associated hardwood species including Acer rubrum, Betula papyrifera, and Fraxinus americana. Conifers are usually present at low abundance. Characteristic species include Pinus strobus, Tsuga canadensis, and in the northern portion of the range, Picea rubens. Oaks are generally not present, although Quercus rubra and (southward) Quercus alba may be present in low numbers. Characteristic understory shrubs or subcanopy trees include Viburnum lantanoides, Acer spicatum, and Acer pensylvanicum. The patchy herbaceous layer is a mix of ferns, rhizomatous herbs and clubmosses. Characteristic species include Dryopteris intermedia, Dryopteris campyloptera, Huperzia lucidula, Maianthemum canadense, Clintonia borealis, Trientalis borealis, Oclemena acuminata (= Aster acuminatus), Uvularia sessilifolia. Occasional species include Aralia nudicaulis, Trillium erectum, Trillium undulatum, Streptopus lanceolatus (= Streptopus roseus), Cinna latifolia, Thelypteris noveboracensis, Solidago macrophylla, and Medeola virginiana. The bryophyte layer may include Dicranum spp. and Leucobryum glaucum. At higher elevations any of the understory herbs characteristic of montane spruce-fir forests may be locally abundant. Sugar maple leaf litter is high in nitrogen relative to lignin and thus decomposes rapidly, increasing the nutrient pool in the soil organic layer. Structure and composition of the forest are maintained primarily by single small tree-fall gaps. Yellow birch is maintained in the system by mineral soils on "tip up mounds." This type is related to the more enriched Acer saccharum - Fraxinus americana - Tilia americana / Acer spicatum / Allium tricoccum - Caulophyllum thalictroides Forest (CEGL005008), which is characterized by a different suite of herbs and by less beech and more ash in the canopy. Sites intermediate between the two, with sugar maple as the canopy dominant and a somewhat enriched herb flora, are distinguished as Acer saccharum - (Fraxinus americana) / Arisaema triphyllum Forest (CEGL006211). There is also a gradation from pure northern hardwoods to mixed conifer-hardwood forests, Tsuga canadensis - (Betula alleghaniensis) - Picea rubens / Cornus canadensis Forest (CEGL006129) and Picea rubens - Betula alleghaniensis / Dryopteris campyloptera Forest (CEGL006267). Northern hardwood forests with a white pine supercanopy have been segregated as Acer saccharum - Pinus strobus / Acer pensylvanicum Forest (CEGL005005). Oak - northern hardwood forests, Quercus rubra - Acer saccharum - Fagus grandifolia / Viburnum acerifolium Forest (CEGL006173) have oak as a more prominent canopy constituent.
Accession Code:
VB.CC.19980.ACERSACCHARUMBE
Plot-observations of this Community Concept:
0
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