Eurasia: altitudinal belts, population and political map

Nearly half of Eurasia is mountain. Altitudinal belts appear because temperature and moisture change with height: temperature falls about 6 °C for every 1 000 m climbed. The number of belts depends on the mountain’s geographical position, height, direction and exposure to moist winds. The lowest belt always matches the natural zone where the mountain lies. On the southern slope of the Himalayas (about 28° N, 85° E) there are the most belts: at the foot the marshy jungle called terai (bamboo, palm), above it tropical wet forests, evergreen forests, broad-leaved forests, coniferous forests, subalpine and alpine meadows, and at the top snow and glaciers. The Alps (about 46° N, 10° E) have fewer belts: broad-leaved and coniferous forests, subalpine and alpine meadows, snow. The northern slope of the Caucasus has steppe, forest-steppe, mixed and coniferous forests, meadows and glaciers. In general the number of belts increases from the pole towards the equator: a polar mountain may have one belt, one in the taiga three, and one in the steppe up to seven. The terai climate allows two harvests a year: rice and jute in summer, wheat and barley in winter. The Ural Mountains show both latitudinal zonality and altitudinal belts, because they stretch far from north to south.