The Arctic and Alpine Tundra: An Ecological Introduction
Covering approximately 14% of the Earth’s landmass, the tundra extend through two distinct cold and dry regions: the arctic tundra comprises areas above the taiga belt, occupying parts of Alaska, Canada, Greenland, and Siberia; comparatively, the alpine tundra involves mountainous elevations above the timberline (Latham, 2010). Coastal stretches of Antarctica also feature expanses of tundra, as do several islands about the continent, including some with subantarctic designations in the Australasian ecozone (Latham, 2010). Accordingly, the tundra’s arctic and alpine biomes accommodate various ecological relationships, offering unique environments for both endemic and migratory organisms. The arctic hare, for example, boasts an impressive range across Northern Canada and Greenland’s shores (Gray, 1993). Its short ears and spherical posture complement an undercoat, allowing the conservation of heat while demonstrating adaptation to the winter’s subzero extremes (Gray, 1993). Comparatively, the woolly lousewort constitutes one of the arctic tundra’s earliest spring flowers, its well-developed taproot promoting perenniality (Porsild, 1953). Nectar within the corolla tube’s base encourages pollination, and the dense rosettes of pinnately divided leaves are appropriate for both animal and human consumption (Porsild, 1953).
Essentially, the arctic and alpine tundra feature resilient biodiversity, their tracts of treeless ecosystems epitomising interactions among versatile organisms and harsh seasonal conditions. Nevertheless, the effects of global warming and climate change have been particularly drastic for the planet’s coldest biomes (Latham, 2010). Rising levels of atmospheric carbon dioxide and other greenhouse gases strongly suggest anthropogenic influences on such environmental crises (Corell, 2006). Rapidly increasing temperatures are precipitating greater permafrost thaw depths, and habitats are collapsing as sea levels threaten to engulf coastal communities amidst a widespread glacial melt (Latham, 2010). Ultimately, the tundra’s transformation coincides with worldwide repercussions, and as temperatures continue to climb, scientists hypothesise that Arctic regions may encounter permanent elimination (Latham, 2010). Unless society reduces emissions and commits to a more limited ecological footprint, the tundra’s animal and plant populations face bleak uncertainty with respect to both habitat degradation and unnatural rates of extinction (Corell, 2006).
As one of the planet’s last biomes to support significant numbers of caribou, muskox, and bear, the arctic tundra provides unparalleled examples of cold adaptation among mammals (Molles & Laursen, 2020). The singing vole, for instance, thrives amidst the subnivean zone: a space between the frozen ground and bottom of the snowpack (Latham, 2010). Hardy roots and stems deliver sustenance to the animal, and the niveous cover affords an ideal shelter against predation (Latham, 2010). Other animals remain outside, insulated by layers of fur: as winter approaches, some species depart for warmer climates, while others tolerate the elements or hibernate for the season (Latham, 2010). Camouflage is prevalent among numerous residents, applying to arctic hares and foxes, each of which changes from grey to white as snowfall blankets the biome (Latham, 2010).
Birds and insects also endure throughout the arctic tundra: each summer, native ptarmigans and snowy owls are joined by a multitude of migratory species as swarms of mosquitoes and midges emerge from iceless ponds and streams (Molles & Laursen, 2020). Herbaceous plants and woody shrubs stimulate the food chain, and soils are rich in organic matter: evidence of well-established ecological pyramids (Molles & Laursen, 2020). Accordingly, the tundra’s botanical species also exemplify adaptations, their shortened heights and toughened stems accomplishing resistance to bitter winds (Molles & Laursen, 2020). The purple saxifrage, for example, grows as a cushion plant, hugging the ground in clusters: its roots proliferate in crevices, spreading between rocks, which absorb the warmth of sunlight (Latham, 2010).
Ultimately, plants are imperative to the tundra’s ecological features, their implications in natural processes reaching far beyond their territories. Krummholz, for example—formations of stunted vegetation—contribute to the alpine ecotone between tundra and forest biomes (Sveinbjörnsson et al., 2002). The presence of individuals affects the distribution of wind and snow, ameliorating conditions for the treeline’s coniferous growth (Sveinbjörnsson et al., 2002). Although such dynamics illustrate the interwoven complexities of ecological success, global warming continues to jeopardise the tundra’s future. Offshore oil extraction accelerates the loss of sea ice, and the consequent retreat of glaciers disrupts the environment’s integrity, resulting in vanishing habitats (Corell, 2006). Polar bears, for example, are swimming greater distances in search of food, the scarcity of prey items directly associated with glacial fragmentation (Latham, 2010). While some bears persist amidst the disadvantage, others succumb to starvation or drown in their pursuit, effectively foreshadowing further catastrophe as humanity saunters towards less pollution and fewer destructive industries (Latham, 2010).
References
Corell, R. W. (2006). Challenges of climate change: An Arctic perspective. Ambio, 35(4), 148–152. https://www.jstor.org/stable/4315712
Gray, D. R. (1993). Behavioural adaptations to arctic winter: Shelter seeking by arctic hare (Lepus Arcticus). Arctic, 46(4), 340–353. https://www.jstor.org/stable/40511436
Latham, D. (2010). Tundra. Nomad Press.
Molles, M. C., Jr., & Laursen, A. (2020). Ecology: Concepts and applications (5th Cdn. ed.). McGraw Hill.
Porsild, A. E. (1953). Edible plants of the Arctic. Arctic, 6(1), 15–34. https://www.jstor.org/stable/40506558
Sveinbjörnsson, B., Hofgaard, A., & Lloyd, A. (2002). Natural causes of the tundra-taiga boundary. Ambio, 23–29. https://www.jstor.org/stable/25094572
