Invalid Unit Specified
F028 Boreal Grassland & Shrubland Formation

The U.S. National
Vegetation Classification
Type Concept Sentence: Boreal Grassland & Shrubland is dominated by mesomorphic perennial grasses, forbs and shrubs, and is found in the northern mid-latitude (boreal) regions of North America and Eurasia, between 55° and 70°N, with extended cold winters and short mild summers.
Collapse All::Expand All
Common (Translated Scientific) Name: Boreal Grassland & Shrubland Formation
Colloquial Name: Boreal Grassland & Shrubland
Hierarchy Level: Formation
Type Concept: Boreal Grassland & Shrubland is dominated by mesomorphic perennial grasses, forbs and shrubs, and is found in the northern mid-latitude (boreal) regions of North America and Eurasia. It is associated with cold semi-arid to moist climates, with extended cold winters and short mild summers, and geographically occurs mixed with boreal forests and wetlands. The climate generally favors establishment of forest vegetation; thus, the absence of forest vegetation is a result of local conditions related to water regime, soil parameters, or disturbance regimes. The present assemblages of plants and animals date to after the Pleistocene, following glaciation, when modern climates were established. Wildfires and grazing also play a role in some of these grasslands.

Along with the mesomorphic perennial grasses, shrubs, and forbs, mosses and lichens can also play an important role. Boreal tree growth forms are not major components of the vegetation, except as a scattered layer (typically <10%). In disturbance situations, Boreal Grassland & Shrubland can grade to 1.B.1 ~Boreal Forest & Woodland Formation (F001)$$ and may not be clearly separated from it floristically.
Diagnostic Characteristics: Mesomorphic perennial grasses and shrubs are the most common growth forms in this formation, with a variable amount of perennial forbs. Trees are scattered to minimally present (typically <10% cover) in the northern mid-latitude regions of North America and Eurasia, extending from cool-temperate regions into the boreal region between 55° and 70°N latitude.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: Clarification of the growth forms, distribution and extent, and ecological processes that control boreal shrublands and grasslands is needed. Examples of vegetation from western boreal include: (1) Betula nana and/or Salix glauca shrublands and Festuca altaica grasslands in cold air-influenced valleys and high-elevation areas below the alpine; (2) Elymus trachycaulus grassland or Amelanchier alnifolia / Leymus innovatus / Arctostaphylos uva-ursi scrub on warm aspects, often on coarse-textured materials; and (3) Post-fire disturbance vegetation that can be dominated by willows and may exclude tree regeneration.
Similar NVC Types:
F012 Temperate Grassland & Shrubland, note: This type is currently separated based on geography and climate.
Physiognomy and Structure: Boreal Grassland & Shrubland is dominated by mesomorphic perennial grasses, forbs and shrubs. Mosses and lichens can also play an important role. Boreal tree growth forms are not major components of the vegetation, except as a scattered layer (typically <10%). In disturbance situations, Boreal Grassland & Shrubland can grade to 1.B.1 ~Boreal Forest & Woodland Formation (F001)$$ and may not be clearly separated from it floristically.
Floristics:
Dynamics: No Data Available
Environmental Description: Climate: This type is associated with cold semi-arid to moist climates, with extended cold winters and short mild summers, and geographically occurs mixed with boreal forests and wetlands. The climate generally favors establishment of forest vegetation; thus, the absence of forest vegetation is a result of local conditions related to water regime, soil parameters, or disturbance regimes. There are lengthy periods of freezing temperatures with the coldest month isotherm of -3°C, and the growing season generally averaging less than 100 days, occasionally interrupted by nights of below-freezing temperatures. Snow may be present for extended periods (7-10 months) and soils are frozen in winter. Annual precipitation is 38-50 cm (15-20 inches). The northern and southern boundary of these boreal grasslands may be similar to that of boreal forest, but the reasons for the presence of grassland and shrubland rather than forest typically reflects water regime, soil characteristics, disturbance regime, and local climate that prevent tree growth.
Geographic Range: This formation is found in the northern mid-latitude regions of North America and Eurasia, extending through much of the boreal region between 55° and 70°N latitude.
Nations: CA, US
States/Provinces:
Omernik Ecoregions:
Plot Analysis Summary:
Confidence Level: Low
Confidence Level Comments:
Grank: GNR
Greasons:
Name:Database Code:Classification Code:
Class 2 Shrub & Herb Vegetation C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland S18 2.B
Formation 2.B.3 Boreal Grassland & Shrubland F028 2.B.3
Division 2.B.3.Na North American Boreal Grassland & Shrubland D025 2.B.3.Na
Concept Lineage:
Predecessors:
Obsolete Names:
Obsolete Parents:
Synonomy:
Concept Author(s): Hierarchy Revisions Working Group, Federal Geographic Data Committee (Faber-Langendoen et al. 2014)
Author of Description: D. Faber-Langendoen, S. Ponomarenko and D. Meidinger
Acknowledgements:
Version Date: 17Oct2014
References:
  • Faber-Langendoen, D., T. Keeler-Wolf, D. Meidinger, C. Josse, A. Weakley, D. Tart, G. Navarro, B. Hoagland, S. Ponomarenko, J.-P. Saucier, G. Fults, and E. Helmer. 2015c. Classification and description of world formation types. General Technical Report RMRS-GTR-000. USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO.