Common (Translated Scientific) Name: Temperate & Boreal Alpine Tundra Formation
Colloquial Name: Temperate & Boreal Alpine Tundra
Hierarchy Level: Formation
Type Concept: Alpine dwarf-shrublands, forb meadows and grasslands occur above treeline in temperate and boreal regions, predominantly in North America and Eurasia, with more isolated occurrences in the Southern Hemisphere. Creeping, matted and low upright dwarf-shrubs may occur, along with alpine grasses and forbs. The ground layer density varies from densely vegetated to open, rocky, rubbly, or frost-sorted habitats, and includes fell-field, boulderfield, tundra, heath and meadow. Bryophyte and lichen cover also varies considerably. The treeline varies depending on latitudinal shifts in climate, moisture and type of mountain range, including its size and degree of isolation. For example, from 1650 m in the Andean steppe of Argentina to 3300-3600 m in the Himalayas, Southern Rocky Mountains and Californian Sierra Nevada to 2300 m in the Lesotho Plateau of South Africa.
Diagnostic Characteristics: Alpine dwarf-shrublands, forb meadows and grasslands occurring above the continuous forest line in temperate and boreal regions. Vegetation is dominated by graminoids, low creeping or matted dwarf-shrubs, and perennial forbs, often in cushion or rosette form. Krummholz and alpine vegetation on scree or talus are also placed here.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: Excludes very sparse alpine semi-desert vegetation, where the alpine regions grade into high-elevation deserts. Soils show cryogenic features. Krummholz is placed here. Scree and talus are also placed here. Fell-fields, which are placed here, have a mix of nonvascular and vascular plants.
Placement of alpine vegetation in arctic and subarctic regions is under review. In those regions, the vegetation is beyond the latitudinal limits of trees. If alpine vegetation exists in those regions, then the subclass should include Arctic or Subarctic in the name. Alpine tundra of most Eurasian and North American mountains is similar to that of the Arctic but with richer flora (Quinn 2008).The growth form distinctions between alpine vegetation and polar tundra need further review.
Alpine tundra of most Eurasian and North American mountains is similar to that of the Arctic but with richer flora (Quinn 2008).
Similar NVC Types:
F031 Polar Tundra & Barrens, note: "Occurs latitudinally beyond the treeline, though may extend southward into mountains of the subarctic (subpolar) woodland regions."
F022 Tropical High Montane Scrub & Grassland, note:
Physiognomy and Structure: Creeping and matted dwarf-shrubs and occasional trees may occur, along with alpine grasses and forbs, including cushion forms of dwarf-shrubs and forbs. Krummholz growth forms may also occur. The ground layer varies from densely vegetated to open, rocky, rubbly or frost-sorted habitats (Whittaker 1975, Billings 2000, Quinn 2008). An extended list of alpine growth forms is provided by Billings (2000, Table 14.3).
Dynamics: No Data Available
Environmental Description: Treeline varies depending on latitude and the "mountain mass" (i.e., large mountain masses retain more heat and tend to have higher treeline elevations, whereas smaller and more isolated mountain masses tend to have lower treeline elevations). In addition to elevation, exposure to wind is a key factor in the type of vegetation; in snowy regions, it impacts the depth and duration of snow cover and, hence, protection of the vegetation, length of growing season, and soil moisture conditions.
Climate: The "tundra" climate of high altitudes does not necessarily correspond to that of high latitudes (i.e., Arctic tundra). Although both regions have low mean annual temperature and short growing seasons, and experience a seasonal change in sun angle (high in the summer, low in the winter), the light regimes are quite different. Alpine regions never experience 24 hours of day or night; day length varies with latitude. And although permafrost occurs on high mountains, it does not produce the kinds of landforms found in the Arctic because few flat sites are available. Conversely, avalanches and rockslides are common in alpine regions, but do not occur in the Arctic (Billings 2000, Quinn 2008). Some alpine regions can have very deep snow (several meters), whereas the Arctic generally has low snow cover.
Soil/substrate/hydrology: Most alpine soils are regularly disturbed by freezing, erosion and downslope slides, and contain a mix of rocks and fine particles (Quinn 2008). Three major types of soils occur in the alpine regions: (1) Poorly developed rocky or stony soils (or Entisols) are sometimes called Lithosols when formed on bare rock of slopes and ridges and Regosols when formed on unconsolidated rock-like talus, scree, or rubble (soil orders from Soil Survey Staff (1999)) [see Brady and Weil (2002) for comparison of U.S. soil orders with Canadian and FAO systems]. Both types are shallow, dry and azonal. (2) Alpine turf and meadow soils (or Inceptisols) are up to 75 cm deep and exhibit distinct horizons. (3) Bog soils (Histosols) are found in depressions or where seepage saturates the ground to a depth of 1 m or more (Billings 2000, Quinn 2008).
Geographic Range: Temperate & Boreal Alpine Vegetation occurs above treeline in temperate and boreal regions around the globe, predominantly in North America and Eurasia, with more isolated occurrences in the Southern Hemisphere.
Nations: CA, US
Confidence Level: High
Confidence Level Comments:
Synonomy: >< Alpine grassland: biome-type 15 (Whittaker 1975)
>< Alpine shrubland: biome-type 14 (Whittaker 1975)
= Mid-latitude Alpine Tundra (Quinn 2008) [Approximately equivalent. Quinn includes alpine scree and talus in her concept.]
Concept Author(s): Hierarchy Revisions Working Group, Federal Geographic Data Committee (Faber-Langendoen et al. 2014)
Author of Description: D. Faber-Langendoen
Acknowledgements: Chris Lea
Version Date: 03Aug2016
- Billings, W. D. 2000. Alpine vegetation of North America. Pages 537-572 in: M. G. Barbour and W. D. Billings, editors. North American terrestrial vegetation. Second edition. Cambridge University Press, New York. 434 pp.
- Brady, N. C., and R. R. Weil. 2002. The nature and properties of soils. Thirteenth edition. Prentice Hall, Upper Saddle River, NJ.
- 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.
- Quinn, J. A. 2008. Arctic and alpine biomes. Greenwood Press, Westport, CT.
- Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. Second edition. USDA Natural Resources Conservation Service, Washington, DC.
- Whittaker, R. H. 1975. Communities and ecosystems. Second edition. Macmillan Publishing Co., New York. 387 pp.