Zonobiome of the Arctic Tundra Climate

Abstract

The largest tundra region completely devoid of forest is an area of 3 million km² in northern Siberia. At most, there are 188 days in the year with a mean temperature above 0°C, and sometimes as few as 55. The low summer temperatures are partially due to the large amount of heat required to melt the snow and thaw out the ground. Winters are rather mild in the oceanic regions but extremely cold in the continental regions (Fig. 155). However, the cold pole still falls within the forest region, near Verchoyansk and Oimekon, although the mean annual temperature at this point is -16.1 °C and the permafrost extends far down into the ground (Fig. 155). The depth to which the ground freezes in winter has no influence upon the vegetation, since the growth of plants depends only on the thickness of the upper soil layer thawing out in summer.