Peter Kropotkin and John Thomas Bealby, 1911 Encyclopædia Britannica, Volume 25… (1911)
“ In the alpine tracts of the north the narrowness of the valleys and the steep stony slopes strewn with debris, on which only lichens and mosses are able to grow, make every plot of green grass (even if it be only of Carex) valuable. For days consecutively the horse of the explorer can get no other food than the dwarf birch. But even in these districts the botanist and the geographer can easily distinguish between the cherñ or thick forest of the Altai and the taiga of East Siberia. The lower plateau exhibits, of course, new characteristics. ”
