A major regional community (*biome
) of vegetation in high mountainous regions and on high-level plateaus. The plants generally grow in thin stony soil and are subjected to high light intensity and high wind speeds. The climate differs from that of the *tundra
as there is daylight in winter and darkness in summer, more precipitation and wind, and a higher degree of solar radiation, but no permafrost. The number of plant species, although limited, is greater than that found in the tundra. Certain drought-tolerant species (e.g. grasses, sedges, mosses, and lichens) are common to both communities. In temperate latitudes there are many brightly coloured flowers in summer on the alpine pastures.
The vegetation changes as the altitude increases due to the associated drop in temperature. The vegetation also differs between north- and south-facing slopes. The lower limit of the alpine zone (see tree line) varies in different mountain regions and also varies with the wetness of the locality and the mass of the mountain range.