Glacial and Tundra Zones. The Coniferous Forest Belt.

Map   Questions.
Examine the zonal map of North America. Compare the zonal positions in North America and in Europe.
North America has the same natural zones as Europe and Asia. In North America, however, the mountain ranges extend in a north­ern to southern direction, and the western, eastern and interior parts of the continent have widely differing climates. Some of the zones, therefore, extend in a northern to southern direction, instead of in a western to eastern direction, as in Europe and Asia.
North America comes very close to Asia, with which it was for­merly connected where the Bering Strait now flows. Their plant and animal life have, for this reason, much in common, although North America has many plants and animals not met with in either Europe or Asia. The vegetation of North America is more varied than that of Europe.
The Glacial Zone. The glacial zone in North America includes Greenland and the northernmost islands of the Arctic Archipelago They are buried beneath a thick sheet of ice that moves down to­wards the sea in places, breaking off and forming icebergs and float­ing islands of ice. These islands were more than once taken for un­known lands, but were later found to have changed position.
In central Greenland the ice sheet is over three metres thick. Only along the coast does the snow melt in summer and a scanty vegetation appear. The population here is very thin and consists

Fig. 158. An iceberg.
These floating mountains sometimes tower several dozen metres above water. The greater part of the mass is below water. A collision with one like this might
sink the largest ship.

mainly of Eskimoes, who earn their living by fishing and hunting sea animals.
The Tundra. The remaining Arctic Sea islands and the entire northern shore of North America consist of tundras that extend across the northern part of Labrador as far as Newfoundland.
The American tundra is similar to that of Eurasia. Here, too, there is a layer of permanently frozen ground beneath the surface that does not let the water through and is the reason for so many marshes and lakes. Vegetation consists mainly of mosses and lichens. Amidst these occur dwarf shrubs and trees.
Here one finds the arctic fox and willow ptarmigan. The North American tundra was formerly the home of many deer, most of which, however, were wiped out. They have been replaced by domes­tic reindeer brought from Europe. Big herds of these reindeer (cal­led caribou) now graze in the western part of the American tundra.
There were formerly great numbers of musk-oxen in the tundra, large animals with long woolly hair. They were mostly wiped out, although a few still remain along the shores of Greenland.
The population, which consists mainly of Indians and Eskimoes, is engaged in hunting. In the coastal lands they fish and hunt sea animals.
The Coniferous Forest Belt. The coniferous forest belt extends south of the tundra from the Pacific to the Atlantic. The chief trees are, as in the Siberian taiga, firs, pines, silver firs and larch. The species are different, however. Coniferous trees grow in combination with deciduous trees, such as birch, aspen and poplar.
There are beasts of prey in the coniferous forests: bears (grizzly and brown) and foxes. Deer and moose are found, as well as such valuable

Fig: 159. A giant sequoia in the
Cordilleras. The trunk of this tree is over 35 me­tres in circumference. Such trees may be several thousand years old.

fur-bearing animals as rac­coon and musk-rat. The musk-rat is now bred also in the Soviet Union.
In the western part of North America the coniferous forests, following the mountain ranges, extend far south.
There still exist sequoias in places, giant conifers that reach a height of over 100 metres (Fig. 159).
Unlike the European taiga, which is quite densely popula­ted, that of America is an al­most uninhabited 'green wilder­ness' (backwoods).The few people living there are engaged in hunting and timber cutting. There is some mining done in places.
Questions and Assignments.

• Compare    the   southern boundaries of the North American, European and Asian tund­ras and taigas. How far south
  do the North American tundras reach?
• Trace the southern boun­daries of the tundras and coniferous forests on the outline map.