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Tundra biome

The tundra biome is the coldest of all of the biomes. Tundra ecosystems generally have low biotic diversity, simple vegetation structure, short growing seasons, and dead organic material that provides the majority of energy and nutrients to the system.

Geographical extent

Arctic tundra covers the poles, as well as Northern parts of the United States, Canada, Greenland, Scandinavia and Russia. Tundra can also be found in alpine regions around the world, where the elevation in mountainous regions causes treeless, cold environments. Tundra environments are largely dominated by permafrost, which is frozen (>2 years in a row) ground.

The southern boundary of tundra in Canada extends from the McKenzie River delta to the southern edge of Hudson Bay and northeast to the Labrador Peninsula. The Canadian Arctic tundra closely follows the extent of continuous permafrost.


Circumpolar distribution of tundra (orange). 


The tundra has cold, desert-like conditions. The growing season typically only lasts two months, thus plants and animals must be adapted to this short window. The average winter temperature is -34 °C, with an average summer temperature of 3-12 °C. The above freezing temperatures in the summer allow for life to flourish, for a short time, on the tundra. As the tundra is often referred to as a desert, precipitation is quite low. Although variable, yearly precipitation, including melting snow, is only 15-25 cm.

In Canada, the tundra ecosystem is often divided into low and high Arctic. Mean daily July temperatures in the low Arctic are 10°C, whereas they are only 5°C in the high Arctic. The Canadian low Arctic experiences 90-120 days of above freezing temperatures, while the high Arctic has an average of 75 days.

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Smith, S. (2011).

Permafrost distribution across Canada.


Due to the harsh climate of tundra environments, plants and animals must be adapted to a short growing season, cold temperatures, permafrost and low precipitation. The tundra is among the least diverse terrestrial environments in the world, as there is a general decrease of biological diversity from the tropics to the poles. The circumpolar tundra flora has approximately 900 species of vascular plants. Put into perspective, a single hectare of tropical rainforest can have over 900 different vascular plant species! There are also an estimated 800 species of non-vascular plants in the tundra.


Plants include a variety of low shrubs, sedges, forbs, grasses, along with mosses, liverworts, and crustose and foliose lichens. Tundra plants are short, robust plants that often grow together in groups to resist cold temperatures and exploit the favourable microclimate near the ground. Furthermore, the leaves of tundra plants are small and leathery which helps lock in moisture. Although there are regional differences, many similar plant species are found across the circumpolar tundra.


The fauna in the tundra are diverse, from large mammals such as polar bears, grizzly bears, wolves, caribou, muskox, and arctic foxes to smaller mammals including lemmings, voles, arctic hares and squirrels. Many migratory birds also occupy tundra landscapes during the summer, along with many insects and invertebrates.

Human populations and climate change

While the tundra is a harsh environment, humans have occupied these landscapes for centuries. Over 20,000 years ago the first people travelled to North America from Asia through tundra landscapes and the Bering land bridge. Canada’s Arctic tundra is occupied by more than 100,000 people, the vast majority identifying as First Nations, Inuit, and Métis. Human activity and presence has increased in the last 50-100 years due to new economic developments from resource extraction.

Tundra regions are currently experiencing the effects of climate change, as these landscapes have experienced the largest increases in temperature. Increases in temperature have caused rising sea levels, loss of sea ice extent, and changes in vegetation and thus habitat for local animals.

Tundra soils

Tundra soils

Soils provide many ecosystem services that are essential for life such as, providing the medium, nutrients, and minerals for plant growth and habitat for many soil organisms, filtering water, and storing carbon.

Tundra soil characteristics

The majority of soils in Arctic tundra regions are classified as a Cryosol. Cryosols are mineral soils that are formed in an environment underlain by permafrost, thus they are often referred to as permafrost soils. Permafrost is ground that remains at or below 0 degrees Celsius for two or more years. Cryosols have an active layer above the frozen ground that thaws and develops seasonally. The frequent freeze-thaw cycles associated with permafrost soils leads to soil-forming processes known as cryoturbation or ‘frost churning’. Frost churning mixes the soil matrix and results in irregular or broken soil horizons, organic intrusions, oriented rock fragments, and silt-enriched layers.

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Turbic cryosol

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Static cryosol

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Organic cryosol

Cryosolic soils consist of unconsolidated parent material, such as glacial till, Aeolian, alluvium, colluvium and organic material. Parent material has a large influence on the pH of Cryosolic soils. There are three great groups in the Cryosolic soil order: Turbic, Static, and Organic. They are defined by two main criteria: the presence/absence of cryoturbation and the nature of the parent material. Almost all Cryosols contain some accumulation of ice, such as ice lenses, layers, and wedges; soil texture is one of the driving factors controlling the amount of ice in mineral soils.

Nutrients such as nitrogen, potassium, and phosphorus are generally low in Cryosolic soils as they are generally locked into the surface organic matter. However, organic carbon can be found in high concentrations in Cryosols, especially Turbic Cryosols. Under the current climate, Cryosols act as important carbon sinks which is vital for global climate regulation.

Soil texture, moisture regime, vegetation cover, and the organic surface layer control the thickness of the active layer in Cryosolic soils. The active layer supports all biological activity and also protects the underlying permafrost; thus is a vital component of the tundra landscape.

Active layer.png

Due to cryoturbation, the Arctic tundra landscape has unique microtopography, often referred to as patterned ground. With the intense frost heaving associated with the season freeze-thaw cycle, geometric shapes are formed by ground material. The freeze-thaw cycle will move, and sometimes sort, soil particles (including large rocks). There are a variety of patterned ground formations, such as polygons, circles, and stripes, due to differences in stone size and freeze-thaw frequency. These formations consist of sorted and/or unsorted material and vary in size, from a few centimeters to several meters in diameter.


For example, frost boils are a common nonsorted circle and are also distinguished by barren centres of mineral soil with vegetation occupying the intercircle areas. Hummocks are a small mound above ground, common in areas with permafrost and seasonally frozen ground, and likely formed by differential frost heaving. Hummocks are often found in groups, thus creating a hummock-hollow (non-hummock area) pattern across landscapes.  

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Frost boils near the MacKenzie Mountains, NWT


Hummock-Hollow landscape near Rankin Inlet, NU

Tundra soil invertebrates

Invertebrates are key contributors of ecosystem services such as herbivory, decomposition, nutrient cycling, and pollination. Tundra soil invertebrates must be adapted to the harsh conditions associated with the ecosystem, thus many of them have life history traits that allow them to remain dormant throughout most of the year. There are an estimated 2000 different species of soil invertebrates in the Arctic, of which the majority are mites, springtails and enchytraeids. These three groups of invertebrates are known to have large global populations.

Mites occupy a wide range of ecosystems and are important decomposers. Mites often go unnoticed, as they are quite small; however, they are diverse and inhabit organic debris of all kinds.


Springtails do not directly control decomposition of organic matter in soil, but they do have significant control of soil microbial communities.


Similar to springtails, enchytraeids do not decompose organic matter as they feed on living material. Enchytraeids can also strongly influence the bacterial community and plan an important role in nutrient cycling, specifically in terms of nitrogen mineralization.







Photographs through a microscope of an enchytraeid, mite, and springtail from nearby Rankin Inlet, Nunavut.

Tundra vegetation

Tundra vegetation

Vegetation supports the development of soil and nutrient cycling, controls the climate and water purification, and provides food, fuel, and medicine to local animal and human populations.

Tundra plant adaptations

Tundra plants have evolved a number of key traits that allow them to survive and flourish in their harsh environment. Some of which include:

1) Prostrate growth form


Instead of growing erect, like most trees and shrubs, many tundra plants grow along the ground in a mat-like form, which enables them to avoid harsh wind, take advantage of the warmer microclimate near the ground, and be protected under the snow during winter months.

2) Long-lived, evergreen habit and/or perennial


Evergreen habit, retaining leaves year-round, enables plants to conserve nutrients. Furthermore, most tundra plants are perennial, which means they can grow and flower quickly after snowmelt thus adapting well to the short growing season.

3) Shallow rooting system


Due to the presence of permafrost, only a thin layer of soil thaws each year; shallow rooting systems allows plants to survive and access water and nutrients during the growing season.

4) Tolerant of low nutrient conditions


High root:shoot ratio, seasonal storage of minerals, efficient nutrient absorption in low temperatures, retaining leaves over the winter are all examples of Arctic tundra plant characteristics that enable them to deal with limited access to nutrients.

5) Tolerance to desiccation, snow, frost during growing season

Small, thick, leathery leaves help tundra plants to avoid water loss.

Vascular plants

  • Growth rates of forbs, broad-leaved herbaceous plants, have very rapid growth rates after snowmelt due to reserves stored in belowground roots.

  • Graminoids, including sedges and grasses, are found throughout the tundra from wet soils to well-drained sites. Similar to forbs, graminoids grow very quickly after snowmelt. Many species have growth forms adapted to tundra conditions, such as leaf angles to optimize intercepting solar radiation and large rhizome and root systems.

  • Cushion, rosette, mat-forming species (e.g., Draba spp., Cerastium spp., Dryas spp., Saxifraga spp.) generally have evergreen leaves, grow slowly and are long-lived. They can be found in wind-exposed areas due to their growth form adaptation.

  • Woody shrubs (from the Betulaceae, Ericaceae, and Salicaceae families) are common in the low Arctic, less so in the high Arctic, and both evergreen and deciduous are present. Evergreen shrubs are more conservative, slow-growing shrubs with low photosynthetic rates and nutrient levels in their leaves. Deciduous shrubs have larger amounts of carbon allocated to roots and woody stems, and grow quickly once the snow melts; photosynthetic rates are faster than other tundra growth forms and nutrient requirements are also greater.

Many Arctic tundra plants have a number of the key traits listed above.


Alpine bearberry

Scientific name: Arctostaphylous alpina

Inuktitut name: Kallat, Kallaqutit, Kallahutik


Often found on hummocks covered in moss at the edges of bogs. Occasionally in acid rocky, gravelly places and rocky tundra. Mat-forming, trailing, dwarf shrub usually between 10-30 cm tall with a woody stem and straggling branches up to 50 cm long. Berries are eaten by humans and animals, especially bears. The leaves can be used for a medicinal tea to relieve general stomach ache and kidney ailments. 

Common vascular plants near Meliadine mine site

Red bearberry

Scientific name: Arctostaphylos rubra

Inuktitut name: Kublak, Kallahutik

Found in tundra dwarf heath, commonly in mountain avens communities of alpine and arctic regions. Mat-forming, trailing, dwarf shrub that can be taller than Alpine bearberry, between 20-45 cm tall with a woody stem and straggling branches. Unlike Alpine bearberry, leaves of red bearberry are deciduous. Berries can be eaten, but other more attractive berries are consumed first. The berries are thought to quench your thirst and good when added to meatballs.

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Alpine bearberry

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Red bearberry

Mountain avens

Scientific name: Dryas integrifolia

Inuktitut name: Malikkaat, isuqtannguat, isurramuat, qasilinnait

Common habitat including tundra, slopes, ridges; dry moderately well-drained areas such as rocks, gravel, sand. Dwarf shrub, usually less than 15 cm tall, with horizontal stems branching to form large mats. Leathery leaves and most remain on the plant over the winter. Plants can be used to track the seasons: they fold and twist in different directions in summer and winter. In the summer, twisting and uncoiling corresponds to when birds lay eggs, caribou moulting, and when caribou skins are suitable for clothing.


White heather

Scientific name: Cassiope tetragona

Inuktitut name: Itsutit, plantiksutit, qijuktaat

Grows on ridges and heaths, often in high abundances. Dwarf shrub generally only 5-10 cm tall. Stems can go erect or along the ground, branching extensively to create mat-like plants. Traditionally been used for lighting fires to boil water for tea, insulating roofs, and bedding.  Large numbers of plants have been used as a raft when they are wrapped and sewn inside caribou skins.


Lapland rosebay

Scientific name: Rhododendron lapponicum

Inuktitut name: Qijjuttaaqpait tipilitt

Common throughout the tundra, slopes, ridges, dry meadows. Dwarf shrub, 5-10 cm tall, with many branches and rhizomes that allows them to grow together in large areas. Flowers are up to 2 cm across when fully open.


Arctic willow

Scientific name: Salix arctica

Inuktitut name: Suputiit, suputiksaliit, uqaujait, uqaujaq

Occupies most arctic habitats, including hummocks, polygonal tundra, snowbeds, dry calcareous gravel and coarse sandy soil. Dwarf shrub, 3-25 cm tall, with stems growing upwards or along the ground; generally forms colonies by layering. Inuktitut names refer to young willow leaves that were eaten with pieces of blubber. Arctic willow can be added to rancid blubber to make a gum. The roots can be peeled and bitten to relieve a sore throat. Arctic willow is often grazed by muskox and arctic hares.


Scientific name: Oxytropis arctobia

Found on ridges, moderately well-drained areas; gravel, silt and clay soils. Perennial herb, 1-5 cm tall that grows in clusters or tufts. Branches extensive at ground level and create cushions of plants. Flowering stems hairy with five purple, blue or pinkish purple petals with contrasting markings of purple in the upper half and white below.


Labrador tea

Scientific name: Rhododendron tomentosum

Inuktitut name: Qijuktaaqpait

Habitat includes peaty soils, moss and lichen tundra areas. Low growing shrub, 10-30 cm tall, with underground rhizomes and many stems along the ground to create a mat. Stems have been used as a chewing tobacco, leaves and stems can be made into a tea, which has a calming effect and is used as a remedy for bladder problems, and aches and pains.


Water sedge

Scientific name: Carex aquatilis

Inuktitut name: Kilirnait, iviit, ivisuka, ivitsuskaka

Common in meadows, hummocks, near edges of small ponds, depressions, and along streams. Perennial herb, 10-50 cm tall, that grows in tufts connected by rhizomes.


Scientific name:

Vaccinium uliginosum

Inuktitut name: Kigutangirnait, naqutit, kigutangirnaqutit, nanuq

Common in turfy tundra, slopes (seepage, scree, dry mesic). Dwarf shrub, 5-15 cm tall, branching extensively to shape mats. When branches touch the ground, roots can develop. Berries are recommended to help diarrhea, and are used in many dishes such as jams, pies, muffins. The leaves and stems can be used to make tea.

Mountain cranberry

Scientific name:

Vaccinium vitis-idaea

Inuktitut name: Kimminnait, Kimminaq, kimminaqutik

Found on hummocks, tundra, slopes; dry to well-drained areas, rocks and sand. Dwarf shrub, 2-10 cm tall, that creeps along the ground branching extensively to form mats. Leaves can be used to make tea, and berries often eaten mixed with meat, fats, fish, blubber, or as jam. Berries can be consumed raw or boiled to ease a sore throat. Juice from the berries can treat kidney problems or colds.





Non-vascular plants and lichen

Non-vascular plants, or bryophytes, lack the vascular tissue system (phloem and xylem) that carry nutrients and water to the different parts of the plant. Bryophytes include mosses, liverworts, and hornworts. Bryophytes have leaf-like, stem-like, and root-like structures that function similarly to leaves, stems, and roots in vascular plants. Mosses growing in the tundra can continue photosynthesis and growth in colder temperatures than most flowering plants, and can grow back after years of low moisture.

There are over 10,000 species of moss worldwide, with ~1200 found in North America. Mosses can be categorized into three main growth forms: acrocarp, (single stem), pleurocarp (branching stems) and sphagnum (peat mosses). While it is not common for animals to feed on moss, they do feed on the insects that live beneath mats of mosses. If you come across mosses that have been turned over or colonies that seem like they have been ripped apart, this is likely from a rodent or bird looking for something to snack on living in the shelter provided by these dense moss mats.

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Lichens are a symbiosis between at least two different organisms, algae and/or cyanobacteria and fungi. The algae photosynthesize and provide energy for the fungi, while the fungi provide the structure or the house for the algae to live on. Lichens do not have roots and can grow on almost any surface.


Lichens grow in numerous growth forms, from the flat crustose form found growing on rocks, to the more lobed and leafy foliose growth form to highly branched fruticose forms commonly found across the tundra.


Common non-vascular plants near Meliadine mine site

Lamp moss

Scientific name: Aulacomnium turgidum

Inuktitut: Maniq

Colonies of this moss are made up of thick individual stems with leaves pressed tightly to the stems; this gives each stem a swollen appearance. This moss is also characterized by their light yellow/green leaves which make it easy to spot on the tundra. Just keep an eye out for bright yellow patches of these dense spongy colonies.

This moss has been traditionally used by the Inuit in combination with arctic cotton or willow fluff to make a wick for a qulliq (soap stone lamp).


Peat moss

Scientific name: Sphagnum species

Inuktitut: Urju


Sphagnum mosses are characterized by the terminal clusters of branches which create a distinctive ‘mop head’ atop each shoot. They are commonly found in wet areas, around water edges and in low lying areas on the tundra. These mosses grow in dense mats that are spongy and very wet. They absorb and retain large amounts of water.


The high absorbency of peat mosses has lead to their use as diapers and menstrual pads. Additionally, their natural antibacterial properties make them an effective dressing for wounds. These mosses have also been used as extra insulation in clothing and around shelters.

Wooly moss

Scientific name: Racomitrium lanuginosum​

This is a small moss with leaves that taper into a fine curly white tip; therefore colonies of this moss look white or gray. Some large cushions of this moss can appear to have the same texture as sheep’s wool and from a distance can be mistaken for a sleeping sheep!


Snow lichen

Scientific name: Cetraria (Flavocetraria) nivalis

Inuktitut: Nirnait

This medium sized fruticose lichen is bushy with crinkled flat lobed edges and when viewed from a distance, the ivory colour gives it the appearance of small patches of snow. This lichen is not edible, but has been used traditionally as a tea to treat illnesses. While not edible for humans, this lichen is part of the diet of caribou.

Finger lichen

Scientific name: Dactyline arctica

This distinctive looking lichen grows as an erect hollow light brown ‘finger’ emerging from the tundra. Because these lichen branches grow up from the tundra in clusters, they have the appearance of a doll sized hand reaching up out of the tundra!

This lichen is a favourite of nesting birds such as ptarmigans and sandpipers, as these lichen fingers make excellent nesting materials.

finger lichen.jpg

Reindeer moss

Scientific name: Cladonia rangiferina

Although commonly referred to as Reindeer moss, this is a lichen, not a moss! This large fruticose lichen is probably the most well known lichen of the tundra because it is easily recognized and also the main staple of the caribou diet. The bushy appearance of this lichen is caused by the numerous branches making up the majority of its structure.



1) Smith, S. 2011. Trends in permafrost conditions and ecology in northern Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 9. Canadian Councils of Resource Ministers. Ottawa, ON. iii + 22 p.

2) Chernov, Y.I. 1995. Diversity of the Arctic terrestrial fauna. In: Arctic and Alpine Biodiversity: Patterns, Causes and Ecosystems Consequences (eds Chapin, S.F. III & Körner, C.). Springer‐Verlag, Berlin, pp. 81–95.

3) French, H., and Slaymaker, O. 2012. Changing cold environments: A Canadian perspective. Wiley-Blackwell, West Sussex, UK, pp. 321

4) Chernov, Y.I. 1985. The living tundra. Cambridge University Press, Cambridge, Great Britain, pp. 213

5) Kimble, J.M. 2004. Cryosols. Springer-Verlag Berlin Heidelberg, New York, pp. 726

6) Aiken, S., and Mallory, C. 2013. Common Plants of Nunvaut. Inhabit Media, pp. 205






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