Name:
Festuca altaica - Cassiope tetragona Boreal Alpine Tundra Macrogroup
Reference:
NatureServe Biotics 2019
Description:
Boreal tundra vegetation comprises this macrogroup. It occurs in high elevations from north-central British Columbia, through Yukon, to Alaska, in areas of continental climate. Typical tundra vascular species include <i>Artemisia arctica, Carex microchaeta, Dryas integrifolia, Festuca altaica, Luzula spicata, Polygonum viviparum, Potentilla diversifolia, Salix phlebophylla, Salix polaris, Salix reticulata, Sibbaldia procumbens</i>, and <i>Silene acaulis</i>. Mosses include <i>Hylocomium splendens, Polytrichum</i> spp., and <i>Stereocaulon</i> spp.; lichens include <i>Flavocetraria nivalis</i>, among others. Tundra encompasses various microsites with different physiognomies from the driest to more mesic: Very dry rocky and wind-blown sites are mostly characterized by sparse vegetation of <i>Dryas integrifolia, Kobresia myosuroides, Oxytropis podocarpa, Potentilla nana, Saxifraga tricuspidata</i>, and <i>Silene acaulis</i>, and lichens such as <i>Flavocetraria nivalis</i>. Drier climate microsites have open graminoid-dominated communities that are characterized by <i>Festuca altaica, Anthoxanthum monticola ssp. alpinum, Carex bigelowii</i>, and <i>Carex microchaeta</i>; other associated vascular species include <i>Artemisia arctica, Festuca brachyphylla, Luzula spicata, Polygonum viviparum, Potentilla diversifolia</i>, and <i>Sibbaldia procumbens</i>. Nonvascular species include <i>Polytrichum</i> spp., and <i>Cladonia</i> spp. Slightly more moist sites with dwarf-shrub alpine heath are dominated by <i>Cassiope mertensiana</i> or <i>Cassiope tetragona</i> with <i>Salix phlebophylla</i> or <i>Salix polaris</i>, or with an ericaceous mix of <i>Vaccinium vitis-idaea, Vaccinium uliginosum, Empetrum nigrum</i>, and <i>Arctostaphylos alpina</i>. Low shrublands with 15-40% cover occur where moisture accumulates, and are mostly dominated by <i>Betula nana, Betula glandulosa</i>, or <i>Salix arctica</i>, with a dense lichen understory, as well as the moss <i>Polytrichum juniperinum</i>. Some of the wettest sites have meadow species, including <i>Aconitum delphiniifolium, Artemisia arctica, Carex macrochaeta, Festuca altaica, Geranium erianthum, Myosotis asiatica, Parnassia fimbriata, Ranunculus occidentalis, Sanguisorba canadensis, Senecio triangularis, Valeriana sitchensis</i>, and/or <i>Veronica wormskjoldii</i>. Lastly, scattered trees or krummholz may occur at the boundary between forest and alpine tundra at lower elevations, and include <i>Abies lasiocarpa, Picea glauca</i>, or <i>Pinus contorta</i>, depending upon the area. Sites occur on gentle to steep slopes (5-50°) on mountaintops and high plateaus of boreal western North America, mostly from 1000-2000 m in elevation but as low as 100 m in Alaska and over 2000 m in British Columbia. The climate is continental, so snowpack tends to be light. The frost-free period is very short; in some locales, frost may occur at any time. Soils are typically shallow, well-drained, and stony, and can be subject to downslope movement, solifluction, and cryoturbation; permafrost can occur. Wind exposure has a strong influence on site conditions by varying exposure, snow depth, and soil moisture. Although this is a very cold climate environment, daylight is long during much of the growing season due to latitude.
Accession Code:
urn:lsid:vegbank.org:commConcept:40709-{B96D8BAF-34AE-45F1-B414-E261274627E3}
Plot-observations of this Community Concept:
0
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