Alpine tundra is an ecozone that does not contain trees because it has high altitude. Alpine tundra occurs at high enough altitude at any latitude on Earth. Alpine tundra also lacks trees, but the low
er part does not have permafrost, and alpine soils are generally better drained than permafrost soils. Alpine tundra transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as Krummholz. Alpine tundra occurs in an alpine zone
High altitude biome dominated by a few species of dwarf shrubs, a few grasses, sedges, lichens, and mosses. Productivity is low in this biome because of the extremes of climate. Quite similar to tundr
a.
A form of tundra in which the absence of trees is due to high altitude instead of high latitude. It lies roughly between the summer isotherm of 10C and the snow line. (Also called mountain tundra.)
altazimuth coordinate system or horizon coordinate system, astronomical coordinate system in which the position of a body on the celestial sphere is described relative to an observer's celestial horiz
on and zenith . The coordinates of a body in this system are its altitude and azimuth . Altitude is measured from the celestial horizon along the vertical circle through the body and the zenith of the observer. Azimuth is measured along the celestial horizon from the observer's south point (the point on the horizon directly south of him) to the point where the body's vertical circle intersects the horizon. Because the earth rotates on its axis, the altitude and azimuth of a celestial body are constantly changing.