An Arctic–alpine

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

is one whose natural

distribution Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

includes the

Arctic The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...

and more southerly mountain ranges, particularly the

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

. The presence of identical or similar taxa in both the

tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...

of the far north, and high

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have aris ...

s much further south is testament to the similar environmental conditions found in the two locations. Arctic–alpine plants, for instance, must be adapted to the low temperatures, extremes of temperature, strong winds and short growing season; they are therefore typically low-growing and often form mats or cushions to reduce water loss through

evapotranspiration Evapotranspiration (ET) refers to the combined processes which move water from the Earth's surface (open water and ice surfaces, bare soil and vegetation) into the Atmosphere of Earth, atmosphere. It covers both water evaporation (movement of w ...

. It is often assumed that an organism which currently has an Arctic–alpine distribution was, during colder periods of the

Earth's history The natural history of Earth concerns the development of planet Earth from its formation to the present day. Nearly all branches of natural science have contributed to understanding of the main events of Earth's past, characterized by consta ...

(such as during the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate be ...

s), widespread across the area between the Arctic and the Alps. This is known from

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

records to be true for ''

Dryas octopetala ''Dryas octopetala'', the mountain avens, eightpetal mountain-avens, white dryas or white dryad, is an Arctic–alpine flowering plant in the family Rosaceae. It is a small prostrate evergreen subshrub forming large colonies. The specific epithe ...

'', for instance. In other cases, the disjunct distribution may be the result of long-distance dispersal. Examples of Arctic–alpine plants include: *'' Arabis alpina'' *''

Betula nana ''Betula nana'', the dwarf birch, is a species of birch in the family Betulaceae, found mainly in the tundra of the Arctic region. Description It is a monoecious, deciduous shrub growing up to high. The bark is non-peeling and shiny red-copp ...

'' *'' Draba incana'' *''

'' *''

Gagea serotina ''Gagea serotina'', synonym ''Lloydia serotina'', is an Arctic–alpine flowering plant of the lily family. It is widespread across the mountainous parts of western North America, from Alaska to New Mexico, and in Europe is found in the Alps, t ...

'' (syn. ''Lloydia serotina'') *'' Loiseleuria procumbens'' *'' Micranthes stellaris'' *''

Oxyria digyna ''Oxyria digyna'' (mountain sorrel, wood sorrel, Alpine sorrel or Alpine mountain-sorrel) is a species of flowering plant in the buckwheat family (Polygonaceae).Sierra Nevada Wildflowers, Karen Wiese, 2nd ed., 2013, p. 108 It is native to arctic ...

'' *''

Ranunculus glacialis ''Ranunculus'' is a List of the largest genera of flowering plants, large genus of about 1750 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots. The genus is d ...

'' *''

Salix herbacea ''Salix herbacea'', the dwarf willow, least willow or snowbed willow, is a species of tiny creeping willow (family Salicaceae) adapted to survive in harsh arctic and subarctic environments. Distributed widely in alpine and arctic environments ar ...

'' *'' Saussurea alpina'' *''

Saxifraga oppositifolia ''Saxifraga oppositifolia'', the purple saxifrage or purple mountain saxifrage, is a species of plant that is very common in the high Arctic and also some high mountainous areas further south, including northern Great Britain, Britain, the Alps ...

'' *''

Silene acaulis ''Silene acaulis'', known as moss campion or cushion pink, is a small wildflower that is common all over the high arctic and tundra and in high mountains of Eurasia and North America (Alps, Carpathians, southern Siberia, Pyrenees, British Isles, ...

'' *'' Thalictrum alpinum'' *'' Veronica alpina''

References

{{DEFAULTSORT:Arctic-alpine Biogeography