North America: natural zones and regions

North of the Great Lakes natural zones follow latitude, while in the south they run more north–south because of high mountains in the west. In the far north, on Greenland and the Canadian Arctic islands, are arctic deserts: winters colder than –35 °C and summers below +5 °C; plants are only mosses and lichens, animals include the polar bear, walrus and musk ox. South of them lie tundra and forest-tundra, then the huge taiga, made of black and white spruce, larch and fir forests with moose, bears, wolves and lynx. On the Pacific coast, in the wet climate, trees grow up to 80–100 m: Douglas fir and sequoia. The east has mixed and broad-leaved forests (oak, beech, maple); the red maple leaf is a Canadian emblem. In the centre are prairies and steppes, once roamed by bison and now mostly fields. In the south-west are semi-deserts and deserts with sagebrush, cactus and yucca; in the south-east wet monsoon-type forests and savannas. In the mountains altitudinal belts rise from forest, through coniferous forest and mountain meadows, to snowy peaks; bighorn sheep, mountain goats, grizzly bears and pumas live there.