Name:
Pinus resinosa Forest Alliance
Reference:
Midwestern Ecology Working Group...
Description:
This alliance is composed of dry-mesic pine forests found near the western Great Lakes, west to north-central Minnesota and adjacent Ontario, and in the Mid-Atlantic states. Stands of this alliance are characterized by a pine overstory and a poorly developed understory. Pinus resinosa is the dominant overstory species, although Pinus strobus can be a codominant in the canopy and is often more numerous in the sapling and seedling classes (Ohmann and Ream 1971). Mesic sites tend to include not only Pinus resinosa, but Picea mariana, Picea glauca, and Abies balsamea in the canopy, while on dry sites, Pinus banksiana is found (MNNHP 1993). Northern hardwoods such as Acer rubrum, Betula papyrifera, Populus grandidentata, Populus tremuloides, and Quercus rubra sometimes form a subcanopy. The understory ranges from moderately herb- and shrub-rich to extremely poor. In the tall-shrub class, the important species are Amelanchier spp. and Corylus cornuta. In the low-shrub class Vaccinium spp., mainly Vaccinium myrtilloides and Vaccinium angustifolium, Gaultheria procumbens, and Linnaea borealis are important, particularly where gaps in the canopy occur. The herbaceous layer is very poorly represented in most parts of this community's range, contributing only 11% (Ohmann and Ream 1971) of the ground cover in northeastern Minnesota, in contrast with more prominent cover of feathermosses and lichens (35% ground cover) (Grigal and Ohmann 1975). Common herbaceous species include Aralia nudicaulis, Asteraceae spp., Maianthemum stellatum, and Pteridium aquilinum. The predominant moss species are Dicranum spp. and Pleurozium schreberi. Sims et al. (1989) found that the average coverage of feathermoss was greater in the northwest region of Ontario than in the north-central region. This alliance occurs on Precambrian Shield bedrock, mainly on dry to fresh, deep mineral soil. The soil deposition history is both glaciofluvial and morainal. Soil depth ranges from 61-100 cm (Ohmann and Ream 1971). The soils textures are coarse sand or coarse loam soils, as well as some fine sands and silts. Fire is an important natural disturbance in this alliance. Pinus resinosa has extensive adaptations that make it well suited to frequent ground fires and occasional crown fires. Reconstructions of the fire regime (Heinselman 1973, Frelich 1992) in Pinus resinosa stands indicate that a combination of ground fires every 20-30 years and severe crown fires every 100-150 years maintained presettlement Pinus resinosa communities.
Accession Code:
VB.CC.20303.PINUSRESINOSAFO
Plot-observations of this Community Concept:
0
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