Kalaallit Nunaat low arctic tundra
Low Arctic tundra at llulissat, Greenland. Source: Randy Snodgrass
The Kalaallit Nunaat low arctic tundra is the southernmost of the two ecoregions of Greenland; this tundra ecoregion lies below 75°N latitude at Melville Bay on the west coast and 70°N at Scoresby Sund on the east coast. This region is bisected by the Arctic circle. Kalaallit Nunaat is actually the local name for Greenland, which island is geographically a part of North America, though politically a member of Europe. With a total area of over two million square kilometers, Greenland is the world's largest island. However, four-fifths of this vast land area lies beneath a sheet of ice. Low arctic tundra covers the ice-free coastal region of southern Greenland, mostly covered in stunted vegetation, yet teeming with wildflowers such as chamomile, dandelion, harebell, and Arctic poppies, and also wild berries in the lowland areas during summer. Few animals tolerate the harsh environment, but those that are present are fascinating. Polar bear and reindeer (or caribou) have habitats in this ecoregion, as well as a population of muskox introduced from the northeast high tundra ecoregion. Atlantic puffin, whooper swan, rock ptarmigan, and gyrfalcon are just a few of the island’s spectacular birds.
Location and General Description
WWF
Greenland claims the second largest ice cap in the world, smaller only than Antarctica's on the other end of the globe. The ice cap reaches a maximum height of 3700 meters at Gunnbjorn, while the land beneath the ice cover is pressed into a concave basin, extending to altitudes below sea level. Ice-free land is restricted to the coastal fringes, which is considered in two biogeographic divisions: the high and the low arctic tundra. The low arctic tundra lies below 75°N latitude at Melville Bay on the west coast and 70°N at Scoresby Sund on the east coast. This region is bisected by the Arctic circle. The majority of the coastal ice-free area is mountainous, with numerous fjords reaching into the interior, and many islands scattered directly off the coast. Greenland's winding coastline adds up to an estimated 40,000 kilometer (km) perimeter.
Greenland is an old shield geological region; Archaean rocks predominate the low arctic ecoregion, though some areas are covered by Tertiary basalts, such as Gunnbjørns Fjeld in the central east. The sea coast proper is mainly rocky, in some places forming steep cliffs, composed of granite and gneiss. Greenland’s climate is arctic with the exception of the inner fjord region of the extreme southwestern coast. In this region, the mean temperature of the warmest month is above 10°C, climate should be subarctic, and large trees could grow. In southwestern Greenland, lower precipitation and higher summer temperatures result in limited soil leaching, and in some areas, saline soils occur. The cold East Greenland Current makes the east coast colder than the west. The extensive coastline must be considered in two different categories, sea coast proper and fjord coast, of which there are several types.
Tundra comes from a Finnish word meaning, simply, free of forest. The term also now includes the presence of permafrost: the lower soil is permanently frozen, causing poor drainage. Greenland had a subtropical-warm-temperate climate as recently as the early Tertiary period, and plant fossils have been found indicating that the island was covered in forests of Acer, Juglans, Magnolia, Metasequoia, Platanus, and Vitis tree species. Historic global climactic change meant the loss of these forests, though some species may have survived in sheltered refuges. The scattered trees now present are generally dwarf or stunted versions of their ancestors. Vascular flora of Greenland is poor (about 500 species), even when compared to that of the northern coast of Alaska or to Norway above the tree limit. Due to the low [[temperature]s] and long months of ice cover, sheltered ecosystems have little chance to develop, and most of the easily characterized coastal ecosystems in Greenland occur in this low arctic ecoregion. Vegetation within the low arctic ecoregion varies according to altitude, distance from the exposed coastline, and available moisture. Some regions closest to the ice-cap are actually the driest, such as along the west coast, which exhibits a dwarf-scrub heath and steppe-like vegetation. At the head of fjords where the climate is warmer subarctic, sheltered areas support scrub and low forests composed of Alnus crispa, Betula pubescens, and Sorbus groenlandica. Mountainous areas may have distributions of more southerly species scattered in sheltered spots. Within the southernmost portion of Greenland, where the climate is warmest, low birch forests cover less than 15% of land area. The birches (Betula spp.) are generally 0.5-2 m tall, though trees as tall as 10 m can occur. This area is dominated by dwarf-scrub heath (42%), with significant areas of dry meadow (18%) and lichen heath (12%).
The Søndre Strømfjord region on the west coast, where the ice-free land extends farthest inland, displays the most pronounced gradient from maritime to continental vegetation. When compared to the exposed coast, the climate inland has lower precipitation, a shorter duration of snow-cover, warmer summer [[temperature]s] and colder winter temperatures. The vegetation transitions from grassy meadows and rich dwarf-shrub at the coast, to prairie and steppe with occasional salt pans and salt lakes in the interior. Heaths are dominated by Empetrum hermaphroditium toward the coast and Betula and Dryas spp. inland; snow-beds of Salix herbacea and herb slopes Potentilla crantzii are found on the coast; Salix glauca scrub and Carex supina steppe occur inland. At the head of the sound, where the climate should be subarctic, rainfall is actually too low for large trees to grow, and the most developed vegetation is willow scrub that reaches 4-5 m in height along watercourses. Heavy grazing has transformed much of this Salix glauca scrub to dense grasslands of Poa pratensis.
Another factor in the vegetational make-up are the numerous hot springs scattered around Greenland. Many plant species are uniquely associated with this habitat. Disko Island off of the west coast is a hot springs area with a relatively rich vegetation. Herb-rich willow scrubs occur around springs, and the island also has a variety of heath vegetations and species-rich herb slopes.
Biodiversity Features
Illulissat, western Greenland. (Photograph by Randy Snodgrass) Only nine species of terrestrial mammals are native to Greenland: arctic hare (Lepus arcticus), arctic fox (Alopex lagopus - white and blue subspecies), arctic wolf (Canis lupus), caribou or reindeer (Rangifer tarandus), polar bear (Ursus maritimus), muskox (Ovibos moschatus), ermine (Mustela erminea), arctic hare (Lepus arcticus), and collared lemming (Dicrostonyx torquatus), and the wolverine (Gulo gulo). Aside from the polar bear, which is partially marine and has little trouble migrating, Greenland's larger mammals, including humans, reached the island from the northwest over winter ice. However, many of these mammals, including muskox, arctic wolf, ermine, and collared lemming, could not cross the large glaciers of Melville Bay in the west, or the Blosseville Kyst on the East Coast. They are absent from Southern Greenland's low arctic tundra, aside from a population of introduced muskox in the Søndre Strømfjord region. Twenty-seven animals were brought here from 1961-65 from northeastern Greenland, and they have steadily increased to a population of over 3,000. This region is also the most important habitat for the caribou (Rangifer tarandus), and though they and the muskox have similar preferences for food, competition has not yet been apparent. Caribou have interesting dietary habits, eating a wide variety of vegetation, including grasses, sedges, mushrooms, berries, birch and willow leaves and twigs, and [[lichen]s]. The caribou, unlike most mammals, produce an enzyme called lichenase that allows them to digest lichens. This proves to be a good winter food source for the caribou. Due to the low protein content, the animals require less water, as they are the only ruminant (animal with a four-chambered stomach) that can recycle nitrogenous wastes entering the bloodstream back into their rumen for reuse. Caribou also chew their shed antlers, retrieving valuable calcium. Disko Island off of the western coast has only a small population of caribou surviving since their introduction in 1968, despite the availability of food sources.
The ice sheet is not an obstacle to migrating birds, and thus, their distribution is dependent upon season and the availability of food. Even small birds, such as wheatears and snow buntings make transglacial journeys. Greenland's large bird population includes about sixty breeding species, half of which are summer residents only. The threatened and endemic white-tailed eagle (Haliaëtus albicilla) is an example of a bird that does not leave Greenland during the winter; this species is somewhat sedentary, found only in the low arctic tundra on the southwest coast. Birds that have seasonal migrations within Greenland are the rock ptarmigan (Lagopus mutus), snowy owl (Nystea scandica), raven (Corvus corax), and arctic redpoll (Carduelis flammea hornemanni). Among the other characteristic birds, those that head south for the winter have quite varied destinations. The white-fronted goose (Anser albifrons flavirostris) migrates from its summer locale on the west-central coast to Iceland and the U.K. The peregrine falcon (Falco peregrinus tundrius) winters in Central and South America, often returning to its same cliff to nest in Greenland year after year. The snow bunting (Plectrophenax nivalis), the most common bird in Greenland, is ubiquitous around the full perimeter of the country. The West Coast population migrates to North America, while the East Coast residents head to western Asia. Other birds make much farther trips, such as the arctic terns (Sterna paradisaea), which travel to the coast of Antarctica and the subantarctic islands. All told, 235 species of birds have been recorded in Greenland.
Due to the isolated location and arctic climate, Greenland has relatively few small animals. About 60 species of spider and 700 species of insects have been recorded; the insects include 50 butterflies, 2 bumblebees and 1 mosquito. The invertebrate taxa seem to have very different origins; a large percentage of beetles are Palearctic, while the majority of Lepidoptera are Nearctic, being identical to those found in high-arctic Canada. Certain species were historically associated with the rural Norse settlements, and then died out when the Norse left. A few of these, such as the rove beetles Quedius mesomelinus and Xylodromus concinnus, survived by adapting to Eskimo turf huts, but now appear to have disappeared with the turf huts.
Many marine mammals inhabit the waters around Greenland, using the land intermittently. There are six seal species, including ringed seal (Phoca hispida), harp seal (Phoca groenlandica), bearded seal (Erignathus barbatus), hooded seal (Cystophora cristata), harbor seal (Phoca vitulina), and walrus (Odobenus rosmarus). Ungava seal (Phoca vitulina ssp. mellonae), a subspecies of the harbor seal, is included on the IUCN’s Red List of threatened species, and occurs only in Greenland and northern Canada. The hooded seal has four distinct breeding areas in the world, one on each coast of Greenland]and two around northeast Canada and Newfoundland. Animals from all of these groups may congregate off the East Coast of Greenland to molt. The majority of these seals breed on offshore drift ice, and therefore affect the terrestrial ecosystem very little.
Current Status
Southern Cape, Greenland (Denmark). (Photograph by Bill Eichbaum) The Norse began colonizing south and southwest Greenland in 982 A.D. and brought with them cattle and sheep. These herds exploited the natural vegetation until the late 15th century. Birch forests were greatly diminished by clearing for grazing and for attempts to farm cereal crops. An impact was also made by peat-cutting. The Norse settlers introduced many plant species, such as yarrow (Achillea millefolium), sheep’s sorrel (Rumex acetosella), and tufted vetch (Vicia cracca) to the island. Small-scale sheep farming by Danish colonists began in 1782, then went large-scale in 1906, with sheep being grazed year round on natural vegetation. Sheep are now overwintered in barns and fed hay grown for the purpose.
Though the population has always been small in this harsh environment, Greenland has experienced many environmental crises throughout its history. These have been due in large part to overhunting of many of the larger animal populations. Several of these, such as arctic fox, came close to extinction just before regulations were initiated. Populations are generally recovering well, though a regulated amount of hunting is allowed. Overgrazing and mechanical destruction of some species’ food sources has had an effect on populations. The Søndre Strømfjord, the most important area for caribou in Greenland, began to experience a dramatic decrease of populations in the late 1970's, which was explained in part by destruction of lichen areas, climate, and lack of natural predators.
There are eight Ramsar sites along the west coast of Greenland’s low arctic tundra: Aqajarua-Sullorsuaq, Eqalummiut Nunaat-Nassuttuup Nunaa, Kitsissunnguit, Kitsissut Avalliit, Kuannersuit Kuussuat, Naternaq, Qínnquata Marraa-Kuussuaq, Ikkattoq & adjacent archipelago. Most of these are designated due to important [[population]s] of seabirds, which use the sites for breeding, staging, or molting. Eqalummiut Nunaat-Nassuttuup Nunaa is one of the most important areas in Greenland for the threatened goose, Anser albifrons flavirostris, with 3,000 individuals (10% of the world population) gathering there to molt. It is also a calving area for caribou, and the introduced muskox population is slowly spreading into the site. Naternaq is one of the most important wetland complexes in western Greenland, with an extensive marshy plain, many shallow lakes, and winding streams. This area is of particular botanical significance, supporting diverse communities that range from dense moss mats to dwarf scrub heath. Proposals have been made to introduce the muskox due to the abundance of its winter food in the site’s lowland areas.
Types and Severity of Threats
Arctic ecosystems are inherently fragile, due in part to the simplicity of their systems and to the fact that many of the organisms present are existing close to the limits of their survival. Greenland, being particularly poor in species even when compared to other arctic ecosystems, is vulnerable to even the smallest disruption. Aside from direct threats from human activities such as hunting and the alteration of vegetation, the forefront environmental concern potentially facing Greenland is global warming. A 1.8-3.6°C increase in the mean annual temperature of Greenland is predicted for the year 2100. However, Southern Greenland has experienced a cooling of 1-1.6 °C over the past 60 years, which is explained by a decrease in deep water formation in the Greenland Sea, reducing the amount of warm Atlantic water flowing north. This cooling will likely counteract global warming in the low arctic tundra regions, but predictions are quite uncertain to what extent. The snow-free period may lengthen, increasing both the growing season and the active soil layer. These changes would undoubtedly disturb the fragile ecosystem, possibly resulting in the loss of some species.
Further Reading
- Berthelsen, C., I.H. Mortensen, and E. Mortensen. 1993. Atuakkiorfik, Greenland.
- Bliss, L.C. and N.V. Matveyeva. 1992. Circumpolar Arctic Vegetation. Pages 59-90 in F. S. I. Chapin, R.L. Jefferies, J.F. Reynolds, G.R. Shaver, J. Svoboda, E.W., and Chu, editors. Arctic ecosystems in a changing climate: an ecophysiological perspective. Academic Press, Inc., San Diego, CA. ISBN: 0121682501
- Böcher, J. and P.M. Petersen. 1997. Greenland. Pages 685-720 in Ecosystems of the World; Polar and Alpine Tundra. ISBN: 0444882650
- Daniëls, F.J.A. and J.G. De Molenaar. 1993. Ecosystems of the World.
- Kerr, A. and S. Allen. 2001. Climate Change: North Atlantic Comparisons: Climate Change.
- Pielou, E.C. 1994. A naturalist's guide to the Arctic. University of Chicago Press, Chicago, US. ISBN: 0226668142
- RAMSAR. 2000. The Annotated Ramsar List: Denmark (and Greenland). Denmark and Greenland.
- World Wildlife Fund. 2010. Kalaallit Nunaat low arctic tundra ecoregion
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