The permanently frozen ground in the northern latitudes is called permafrost. The layer closest to the surface that thaws during the summer is also part of the permafrost, but is called the active layer. Permafrost is a major feature of the tundra biome.
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes from Kildin Sami tūndâr, which means "uplands, treeless mountain tract." There are two types of tundra: Arctic tundra (which also occurs in Antarctica) and alpine tundra. In tundra, the vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens. Scattered trees grow in some tundra. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline.
Permafrost
Permafrost.
permafrost
permafrost
Permafrost.
permafrost!
Permafrost is the layer of permanently frozen ground that lies underneath the top soil of the tundra.
Tundra is marked by a permanently frozen layer of soil called permafrost, which can be at considerable depth or just below the surface.
permafrost
The region is called the Arctic Tundra. The permanently frozen soil is called permafrost.
permafrost
Permafrost.
permafrost!
Tundra
Permafrost is the layer of permanently frozen ground that lies underneath the top soil of the tundra.
Tundra is marked by a permanently frozen layer of soil called permafrost, which can be at considerable depth or just below the surface.
Permanently frozen soil anywhere is called permafrost.
permanently frozen soil
the tundra
farmafrast