Alpine climate is the typical climate for elevations above the tree line, where trees fail to grow due to cold. This climate is also referred to as a mountain climate or highland climate.
White Mountain, an alpine environment at 4,300 metres (14,000 ft) above sea level in California
The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions. The tree line is sometimes distinguished from a lower timberline, which is the line below which trees form a forest with a closed canopy.
Tree line above St. Moritz, Switzerland. May 2009
In this view of an alpine tree line, the distant line looks particularly sharp. The foreground shows the transition from trees to no trees. These trees are stunted in growth and one-sided because of cold and constant wind.
Alpine tree line of mountain pine and European spruce below the subalpine zone of Bistrishko Branishte, with the surmounting Golyam Rezen Peak, Vitosha Mountain, Sofia, Bulgaria
An alpine tree line in the Tararua Range