(also sparse forest), a forest in which the trees do not form a closed cover and are situated some distance apart. Thin forests, which are a part of the forest tundra, are found on the northern timberline in the northern hemisphere (Eurasia and North America). Several types of thin forests are distinguished: spruce (Norway and Sitka spruces), larch (Siberian and Dahurian larches), and birch (various species, distributed primarily on the Kola Peninsula and in Scandinavia).
The trees in a thin forest are short, rarely reaching a height of 6–8 m. Because of their sparseness, they only slightly influence the lower forest layers, which are similar to tundra (lichen, moss-lichen, and dwarf arctic birch). The grasses in a thin forest are poorly developed; cowberry, blueberry, bilberry, bearberry, and dwarf arctic birch are encountered.
The open, dry, thorny, and frequently low-trunked forests of Africa, South America, and Australia are also called thin forests.