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G788 Laurentian-Acadian Acidic Scrub & Grassland Group

Type Concept Sentence: This Laurentian and near-boreal outcrop group is found across central southern Canada and the upper Midwest of the United States with patchy, often a mosaic of woodlands and open glades typically dominated by various conifers, including Pinus banksiana and Picea mariana, with occasional Picea glauca or Populus tremuloides.

Common (Translated Scientific) Name: Laurentian-Acadian Acidic Scrub & Grassland Group

Colloquial Name: Laurentian-Acadian Acidic Scrub & Grassland

Hierarchy Level:  Group

Type Concept: This Laurentian and near-boreal outcrop group is found across central southern Canada and the upper Midwest of the United States. It is found on ridges or summits of resistant acidic bedrock at low to mid elevations with soils ranging from sands to loams. The vegetation is patchy, often a mosaic of woodlands and open glades and typically dominated by various conifers, including Pinus banksiana and Picea mariana, with occasional Picea glauca or Populus tremuloides. Hardwoods include Quercus rubra, Quercus ellipsoidalis, and Populus tremuloides. Structure can vary from treed to low heath shrubs to open lichen woodland. Common grass species include Danthonia spicata, Oryzopsis asperifolia, and Poa compressa. Dwarf-shrubs include Comptonia peregrina, Juniperus spp. and Vaccinium spp. Pteridium aquilinum may form an almost continuous canopy of fronds in some stands. Exposure and occasional fire are the major factors in keeping the vegetation relatively open.

Diagnostic Characteristics: Patchy mosaic of woodlands and open glades found in the northern Midwest and southern Canada and typically dominated by shrub-form conifers with variable herbaceous cover and areas of exposed bedrock covered by lichens and mosses.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: No Data Available

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: The vegetation is patchy, often a mosaic of woodlands and open glades and typically dominated by various, often shrub-form conifers. There may be a sparse cover (0-10% cover) of trees over 5 m tall. Herbaceous cover varies, with mosses and lichens comprising much of the cover on areas of exposed bedrock.

Floristics: Vegetation is dominated by northern and subboreal species. Typical tree species include Abies balsamea, Picea glauca, Pinus banksiana, Pinus resinosa, and Pinus strobus. Other common species include Acer rubrum, Betula papyrifera, Populus tremuloides, Quercus rubra, and Thuja occidentalis. In some examples, these woody species may form woodlands or thickets of shrub-form trees. Common shrubs include Alnus viridis, Cornus sericea, Corylus cornuta, Oplopanax horridus, Prunus pensylvanica, Salix spp., Taxus canadensis, and Viburnum edule. Dwarf-shrubs may form a distinct layer. Some common dwarf-shrub species include Arctostaphylos uva-ursi, Comptonia peregrina, Diervilla lonicera, Empetrum nigrum, Juniperus communis, and Vaccinium angustifolium. Herbaceous cover varies. Common grass species include Elymus trachycaulus (= Agropyron trachycaulum), Bromus kalmii, Danthonia spicata, and Oryzopsis asperifolia. Forbs of high constancy include Anaphalis margaritacea, Equisetum arvense, Galium triflorum, Gymnocarpium dryopteris, Linnaea borealis, Lycopodium annotinum, Maianthemum canadense, Streptopus lanceolatus (= Streptopus roseus), Symphyotrichum ciliolatum (= Aster ciliolatus), Fragaria virginiana, and Solidago nemoralis. Ferns may dominate some examples, including areas where Pteridium aquilinum may form an almost continuous canopy of fronds. A high cover of exotic or weedy species such as Hieracium aurantiacum, Lactuca serriola (= Lactuca scariola), Phleum pratense, Poa compressa, Poa pratensis, Rumex acetosella, and Verbascum thapsus (Curtis 1959) may be present in some stands. Cladonia spp. and Polytrichum spp. are two abundant nonvascular taxa.

Dynamics:  Exposure, temperature, and thin soils maintain occurrences in an open condition. Some stands may have arisen as a result of previous logging. Fire, both natural and slash fires following logging, may be important in some examples.
Environmental Description:  Stands occur on level plains or rolling uplands with gentle to moderate slopes and in depressions ("frost pockets") in pitted outwash topography. Soils range from loams to fine sands and are somewhat acidic (pH 4.6) and are moderately well-drained to well-drained. Soil characteristics vary depending on the age of the stand.
Geographic Range: This group occurs in the north-central United States and south-central Canada in the Great Lakes region, ranging east to New England.

Nations: CA,US

States/Provinces:  MB, ME, MI, MN, NB?, NH, NS?, NY, ON, QC, VT, WI


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.2 Temperate Grassland & Shrubland Formation F012 2.B.2
Division 2.B.2.Nc Eastern North American Grassland & Shrubland Division D024 2.B.2.Nc
Macrogroup 2.B.2.Nc.4 Laurentian -Acidic Rocky Scrub & Grassland Macrogroup M505 2.B.2.Nc.4
Group 2.B.2.Nc.4.a Laurentian-Acadian Acidic Scrub & Grassland Group G788 2.B.2.Nc.4.a
Alliance A1599 Western Brackenfern - Arctic Brome Sand Grassland Alliance A1599 2.B.2.Nc.4.a
Alliance A3361 Mountain Maple - White Spruce / Bluebead Scrub Alliance A3361 2.B.2.Nc.4.a
Alliance A3908 Common Juniper - Mixed Scrub / Poverty Oatgrass Acidic Bedrock Alliance A3908 2.B.2.Nc.4.a
Alliance A4110 <i>Vaccinium angustifolium - Vaccinium pallidum</i> Northern Rocky Heath Alliance A4110 2.B.2.Nc.4.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: No Data Available
Concept Author(s): J.T. Curtis (1959)

Author of Description: S.E. Menard

Acknowledgements: No Data Available

Version Date: 05-04-15
  • Curtis, J. T. 1959. The vegetation of Wisconsin: An ordination of plant communities. Reprinted in 1987. University of Wisconsin Press, Madison. 657 pp.
  • Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
  • Kost, M. A., D. A. Albert, J. G. Cohen, B. S. Slaughter, R. K. Schillo, C. R. Weber, and K. A. Chapman. 2007. Natural communities of Michigan: Classification and description. Report No. 2007-21, Michigan Natural Features Inventory, Lansing. 314 pp. [http://web4.msue.msu.edu/mnfi/reports/2007-21_Natural_Communites_of_Michigan_Classification_and_Description.pdf]