Nearctic Shrub Tundra - Code: Ne10E

Nearctic Shrub Tundra can grow several feet high, but it is generally made up of taller versions of the same plant species that grow in more exposed areas such as Dwarf Birch and Tea-leaved Willow, combined with a lower layer of Grey Willow.
One’s first impression of tundra in midsummer is a blend of earthy oranges, olive greens, and browns of the mosses and lichens, along with the previous year’s dead growth. Shrub Tundra is the thicker, slightly taller (between 1 and four feet high) Ericaceous-dominated tundra that grows in the better protected, thicker soils (where there is permafrost), as well as farther south (where there is not permafrost) than surrounding Rocky Tundra.  The growing season for most of the tundra is only four months a year, when there are up to 24 hours of sunlight, and the rest of the year the habitat remains dormant; for 200 days, it is buried under snow cover (which actually protects the plants from desiccating winds).    Perennials and shrubs tend to flower early in the season, while annuals or plants without substantial biomass in their root systems flower and seed  later in the season and either wither away, spending  the winter as seeds. 
Therefore, the dominant features of plants of this habitat are that, rather than simply being resistant to extremely cold conditions, they are adapted to a very short growing season with long periods of daylight, and they can withstand the intense drought (through desiccation) of the winter months as well as the exposure to winds when there is no snow cover. Temperature alone would intuitively seem to be the main factor determining vegetation limitations of this habitat, but that is not the case; temperatures in BOREAL CONIFEROUS FORESTS  can be much colder than those of shrubby tundra.

However, these SHRUBBY TUNDRA  areas can be very windy, and at extreme temperatures in areas of permafrost, these winds cause rapid transpiration and desiccation with no chance of replenishment, as all water is frozen. So it is the dry wind rather than temperature that causes the microenvironment where, in the most northern areas,  the surrounding Rocky Tundra to be treeless and SHRUBBY TUNDRA is in the protected areas. Farther south, such as the Aluetian islands and mainland Alaska west of Anchorage, where there is no permafrost,  the situation is reversed. Here the shrubby tundra is on the exposed tops of plateaus, ridgelines and on islands, whereas the more protected areas have SUBARCTIC TUNDRA WOODLAND ana NEARCTIC subarctic tundraBOREAL SHRUBLAND.

This habitats is dominated  by shrubs grow several feet high, but it is generally made up of taller versions of the same plant species that grow in more exposed areas such as European Blueberry, (Vaccinium myrtilus), Dwarf Birch (Betula nana),Tea-leaved and Dwarf Willows (Salix phylicifolia & herbacea),  Empetrum hermaphroditum (a type of Crowberry), Bog Bilberry (Vaccinium uliginosum). The ground cover is dominated by rushes such as Highland Rush (Juncus trifidus), and grasses like the Viviparous Sheep’s-fescue (Festuca vivipara). Between the shrubs, rushes and grasses the rocks and soils are almost completely covered covered by mosses such as Dusky-fork Moss (Dicranum fuscescens) and Wooly-fringe Moss (Racomitrium lanuginosum) and fungi such as Cetraria cucculata, and C. ericetorum.