Abstract for CNVC00234


Picea mariana – Betula papyrifera – Abies balsamea / Clintonia borealis

Black Spruce – Paper Birch – Balsam Fir / Yellow Clintonia
Épinette noire – Bouleau à papier – Sapin baumier / Clintonie boréale

CNVC00234 is a boreal mixedwood forest Association that occurs in Ontario and Quebec. It has a closed canopy dominated by black spruce (Picea mariana) and paper birch (Betula papyrifera), usually with a smaller component of balsam fir (Abies balsamea) and sometimes trembling aspen (Populus tremuloides). Regeneration of these tree species, especially balsam fir and black spruce, dominates the well-developed shrub layer. Less abundant but constant shrub species include velvet-leaved blueberry (Vaccinium myrtilloides), serviceberries (Amelanchier spp.), early lowbush blueberry (V. angustifolium), American mountain-ash (Sorbus americana) and sheep laurel (Kalmia angustifolia). The herb layer is moderately developed and usually includes bunchberry (Cornus canadensis), yellow clintonia (Clintonia borealis), wild lily-of-the-valley (Maianthemum canadense), creeping snowberry (Gaultheria hispidula), twinflower (Linnaea borealis), northern starflower (Lysimachia borealis), goldthread (Coptis trifolia) and wild sarsaparilla (Aralia nudicaulis). The forest floor cover is mainly broad-leaf litter, so the moss layer is poorly developed, with only minor cover of red-stemmed feathermoss (Pleurozium schreberi). CNVC00234 is a mid-seral condition that typically succeeds an early seral, post-fire Association. It is most frequently found on mesic, nutrient-medium sites and occurs in a region with a humid continental boreal climate. As the fire cycle lengthens in the eastern portion of its range, outbreaks of spruce budworm (Choristoneura fumiferana) play a greater role in the dynamics of this Association. Three subassociations are distinguished: typic, Pteridium aquilinum and Acer rubrum.