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The tundra is an extremely harsh, cold, windy, and unique ecosystem found on the extreme north and south latitudes of our Earth. The soil consists mostly of frozen permafrost, which makes it difficult for extended root systems to grow, and water to drain and support a wide variety of plant life.
In physical geography, tundra (/ ˈ t ʌ n d r ə, ˈ t ʊ n-/) 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 , [ 2 ] Alpine , [ 2 ] and Antarctic .
This ecoregion consists of a long range of high rocky mountains of the Alaska Interior running north from the bottom of the Alaska Peninsula, eastwards taking in the Alaska Range and southwards to include the Wrangell and Saint Elias Mountains in eastern Alaska on the Canada–US border as far as Yakutat Bay.
The short (3–4 month) growing season in boreal forests is sustained by greater levels of rainfall than the tundra receives (between 30 and 85 cm or 12 and 33 in per year). This biome is dominated by closed canopy forests of evergreen conifers, especially spruces, fir, pine and tamarack with some diffuse-porous hardwoods.
Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets lower until it reaches sea level, and alpine tundra merges with polar tundra .
Anthropogenic biomes, also known as anthromes, human biomes or intensive land-use biome, describe the terrestrial biosphere in its contemporary, human-altered form using global ecosystem units defined by global patterns of sustained direct human interaction with ecosystems. Anthromes are generally composed of heterogeneous mosaics of different ...
The Holdridge life zones system is a global bioclimatic scheme for the classification of land areas. It was first published by Leslie Holdridge in 1947, and updated in 1967. It is a relatively simple system based on few empirical data, giving objective criteria. [ 1 ]
Biomes vary due to global variations in climate. Biomes are often defined by their structure: at a general level, for example, tropical forests, temperate grasslands, and arctic tundra. [4]: 14 There can be any degree of subcategories among ecosystem types that comprise a biome, e.g., needle-leafed boreal forests or wet