The tundra is one of the harshest biomes on earth that is characterized for its frost molded landscapes, extremely low temperatures, low precipitation levels, poor nutrients and short growing seasons. Dead organic material functions as a nutrient pool and the two major nutrients are nitrogen and phosphorus. Nitrogen is created by biological fixation and phosphorus is created by precipitation.
Location defines the three types of tundra: Arctic tundra, Antarctic tundra and Alpine tundra. The climate and temperature vary depending on where the tundra is located. For example, the winter average for the arctic tundra is -34°C and the summer average is between 3°C and 12°C, and the yearly precipitation, including snow, is between 15 to 25mm. While the average temperature in Inuvik, located on the northern edge of the boreal forest, just before it begins to transition to tundra, is much higher, with the highest temperature is 14.5°C and lowest temperature is -27.5°C.
Ivvavik National Park, which encompasses a portion of the The Canadian Arctic Tundra, is known for its diverse vegetation. In comparison to the other environments, Ivvaik includes a very diverse variety of plants. The vegetation is noted as a treeless tundra, that mainly consists of sedges, as well as shrubs like willow, dwarf birch and cranberry. Up in the mountains, at a higher altitude, there is an alpine tundra of lichens, that replaces the arctic tundra. Scattered patches of wild flowers like avens and saxifrage are also common. The southern end of the park is charachterised by the open strand of stunned spruce and polar.
An important issue is permafrost, which, as a byproduct of climate change, will have a rather dangerous and life threatening fate if the global temperatures continue to rise. Because of the extremely low temperatures, soil is formed slowly. A layer of permanently frozen subsoil called permafrost exists, consisting mostly of gravel and finer material. When the upper surface is saturated with water, bogs and ponds form, providing moisture for plants. A variety of features such as hummocks, tussocks, frost boils, sorted and unsorted circles, and high and low centered polygons, are distinctive to the permafrost terrain.
The tundra and taiga together comprise approximately one-third of global carbon storage in soil, and a large portion of this carbon is located in permafrost in the shape of dead organic matter. For several thousand years, a substantial amount of this organic matter has been preserved; not necessarily because it was inherently difficult to break down, rather because there are no human records of the land not remaining frozen. The organic material would be exposed to microbial decomposition if the thawing of the permafrost occurs at an accelerated rate. This would release carbon into the atmosphere in the form of CO2 and methane (CH4).
There is evidence that suggests that the release of carbon dioxide into the atmosphere has caused climate warming to increase the frequency and intensity of tundra burning in the Arctic over the past few decades. Conversely, larger plant productivity resulting from a longer, warmer growing and fertile season could compensate and equalize the amount of carbon dioxide in the air caused by the carbon emissions from permafrost melting and tundra fires. Indeed, some ecologists and climate scientists suggest that there is a great deal of uncertainty and skepticism about the future of the Arctic’s carbon cycle in the 21st century.
On the other hand, scientists worry that a net transfer of greenhouse gasses from tundra ecosystems to the atmosphere presents the probability to exacerbate changes in Earth’s climate using a positive feedback spiral, in which even the slightest elevation of air temperature at the surface have the potential to set off a chain of events that can lead to further climate warming.
The situation at the Arctic Tundra also poses a few important questions about the wildlife. The northern Yukon has been called the richest area of Canada’s arctic in terms of wildlife, as the diverse vegetation is able to support a wide range of animal life. Habitat for Barren ground caribou, grizzly bears, Dall’s sheep, red and arctic fox and wolverines, while the polar bear abandons his seal hunt to come ashore mainly in winter. The Porcupine caribou herd, one of the world’s largest at over 129 000 animals, is the park’s most prominent feature. Several birds of prey live in the park, including golden eagles, gyrfalcons, peregrine falcons, and rough-legged hawks.
The coastal plain is an important waterfowl nesting area for snow geese and tundra swans. The Firth and Babbage Rivers are prime wintering, spawning, and feeding areas for Dolly Varden Char and arctic grayling. Vole, squirrels and lemmings all nest underground, while marten and porcupine prefer forest cover.
Only about 20 species can call the tundra home! Mammal diversity in the tundra is low as inhabitants that live in these cold landscapes must be adapted to cold temperatures and snow cover. Majority of the species in the Arctic migrate to warmer locations, as hibernation is not an option because very few can survive being inactive in the winter at such low temperatures.
Tundra mammals require a multilayer fur coat, a stocky body, broad and hairy feet or hooves that act as snowshoes, a thick fat layer and small or short appendages and extremities (legs, tails, ears, etc.). These features help mammals survive in this harsh environment. Polar bears meet these requirements. Their thick fur has an underfur that is also covered in guard hairs which prevents almost all heat loss. Furthermore, their hair is actually translucent, it just appears white! Their core is hollow, scattered so it reflects visible light. The other purpose of this“white” fur isalso camouflage, as it helps them be less visible when they go hunting for seals.
However the fur isn’t the only thing that keeps them warm. Their ears are small and round, their tails short and compact, so they conserve more heat. Additionally their black footpads on the bottom of each paw are covered by small, soft bumps known as papillae. Papillae grip the ice and keep the bear from slipping. Tufts of fur between its toes and footpads can help with security as well. The tundra supplies them with food, as they are considered to be marine mammals as they consume seals and other marine animals.
The polar bears’ many adaptations to survive in the extreme cold has enabled them to inhabit and live in warm environments. They sometimes overheat even in Arctic weather when running. The double layer of insulated white fur may prevent them from surviving the hot weather. Their dependence on sea ice makes them highly vulnerable to a changing climate. Polar bears rely heavily on the sea ice environment for traveling, hunting, mating, resting, and in some areas, maternal dens. In particular, they depend heavily on sea ice-dependent prey, such as ringed and bearded seals. Additionally, their long generation time and low reproductive rate may limit their ability to adapt to changes in the environment.
Overtime global warming has also rendered much of the polar bear population redundant. The ice floes on which polar bears catch seals are slowly melting due to global warming. Which means, if humans do not take interest in preventing global warming, the seals and polar bears will be forced to adapt to this changing environment or they are going to be extinct. However Polar bears have relatively high genetic diversity within the species and can disperse over very long distances, suggesting that they may have SOME capacity to adapt to the ongoing changes in the Arctic.
Nevertheless, one of the most lengthy and thorough studies to date of key vegetation in the Arctic tundra provides substantial evidence that dramatic fluctuations in the region are being caused by climate warming. In a study led by the University of Edinburgh, consisting of an international team of scientists at 37 sites in nine countries, shrub growth was explored and collected for a time span of 60 years by analyzing annual growth rings in the plant stems, in order to investigate the links between climate and vegetation change.
The International Arctic Science Committee funded the study, published in Nature Climate Change, where potent data and findings could potentially help improve models of future changes to tundra ecosystems and the influence these changes pose on the global climate.
University of Edinburgh’s School of GeoSciences coordinator for the study, Dr Isla Myers-Smith, stated that: “Arctic shrub growth in the tundra is one of the most significant examples on Earth of the effect that climate change is having on ecosystems. Our findings show there is a lot of variation across this landscape. Understanding this should help improve predictions of climate change impacts across the tundra.” Hence, this showcases that notable changes in one of Earth’s most potent ecosystems are not only a symptom and byproduct of climate change, but research suggests that it may even fuel further warming and aggravate the issue of global warming.
Fun facts: did you know…
- The word “tundra” comes from a word used by the Sami people of northwestern Russia that means “barren land” or “treeless land.”
- The tundra is the world’s youngest biome, having formed about 10,000 years ago at the end of the last ice age
- Canada was inhabited by humans for the past 5000 years
- The Arctic tundra contains the largest amount of freshwater available for biodiversity than any other biome.
- The Arctic ground squirrel is the only species able to hibernate in the biome
- Aurora Borealis also known as Northern Lights is one of the 7 Wonders of the Natural World.
Written by Lina Nikolovska
Sources:
https://www.britannica.com/science/tundra/Effects-of-human-activities-and-climate-change
https://www.sciencedaily.com/releases/2015/07/150706114229.htm
“Climate – Canada.” Canada Climate: Average Weather, Temperature, Precipitation, Best Time, www.climatestotravel.com/climate/canada
Ivvavik National Park – Animals, http://canadianparks.com/yukon/ivvavnp/page3.htm
“A Simple Explanation of the Food Chain in the Tundra Region.” ScienceStruck, ScienceStruck, 13 Mar. 2018, https://sciencestruck.com/tundra-food-chain
“Tundra | Wildlife Journal Junior.” Wildlife Journal Junior, www.nhptv.org/wild/tundra.asp.
Kang, Starr. “Tundra Biomes & Abiotic Factors.” Sciencing, 24 Apr. 2017, https://sciencing.com/tundra-biomes-abiotic-factors-8260321.html
“Characteristics.” Polar Bear Characteristics: Fur, Skin, Paws, Claws, and Weight – Polar Bears International, https://polarbearfacts.net/can-polar-bears-survive-in-warm-climates/
