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These complex interactions between plants, animals and abiotic factors in the tundra are held together by the permafrost layer, located 450 metres (1,480 ft) under the soil. [3] However climate change is causing this crucial layer of frozen soil to melt. As a result, tundra communities are becoming unstable and basic processes are breaking down.
The rationale was to provide a fresh food source to sailors who might become shipwrecked. Rabbits have devastated the islands' plant communities, and have caused serious erosion in places where their numbers have exploded - mostly the eastern half of the islands, where population densities have reached 40+ per acre in some places.
The flora of the alpine tundra is characterized by plants that grow close to the ground, including perennial grasses, sedges, forbs, cushion plants, mosses, and lichens. [28] The flora is adapted to the harsh conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation, and a short growing season.
The impact of human activity on the tundra ecosystems where pikas live has been recorded dating back to the 1970s. [18] Rather than hibernate during winter, pikas forage for grasses and other forms of plant matter and stash these findings in protected dens in a process called "haying". They eat the dried plants during the winter. [19]
Higher still, these give way to dwarf willows and birches above which are tundra, rock and ice. [6] The tundra is too exposed and the climate too severe to support trees and large plants, and here grow mountain grasses and low-growing alpine plants such as mountain avens and purple saxifrage. At even higher altitudes mosses and lichens provide ...
This coast has an arctic climate warm enough to allow plant growth in late-June, July and August only, and even then frosts may occur. On the whole this is a damper, wetter area than the Low Arctic tundra ecoregion that continues along the coast west of here to Quebec. [2]
Many flowering plants of the alpine tundra have dense hairs on stems and leaves to provide wind protection or red-colored pigments capable of converting the sun's light rays into heat. Some plants take two or more years to form flower buds, which survive the winter below the surface and then open and produce fruit with seeds in the few weeks of ...
The majority of plant and animal activity occurs in the few months where temperatures are above freezing in the region, so a speedy reproduction cycle has been evolutionarily favored. [11] Due to the relatively low number and activity level of animals in the tundra, most plants do not produce many seeds, and instead send runners or develop ...