In physical geography, tundra's a biome where the tree growth's hindered by low temperatures and short growing seasons. The term tundra comes from Kildin Sami tūndâr, which means "uplands, treeless mountain tract." There're two types of tundra: Arctic tundra (which also occurs in Antarctica) and alpine tundra. In tundra, the vegetation's composed of dwarf shrubs, sedges and grasses, mosses, and lichens. Scattered trees grow in some tundra. The ecotone (or ecological boundary region)… (More on Tundra)