WESTERN SIBERIA 137 



constantly broken by vast fens and areas of burnt- 

 over forest where only patches of the old woods exist, 

 the rest of the tract being covered with a scrub of 

 raspberry bushes and other shrubs. This is often the 

 aftermath of fire, either due to incendiarism or applied 

 in the interests of a shifting cultivation. On its 

 northern limits the taiga first appears as separate 

 clumps and patches of trees on the slopes of ravines 

 and river valleys. The fir (spruce) tribe predominate 

 in the taiga, but there are many other species of trees. 

 This great forest zone is subdivided as follows : 



Western Siberia. — From the Ural Mountains to the 

 lower reaches of the Enessey and to Lake Baikal : 

 This area is divided into a dry zone and a swampy 

 zone. In the dry zone the predominating species 

 are the so-called Siberian " cedar " or cembran 

 pine (Pinus cembra), a valuable tree which furnishes 

 both timber and an edible seed ; the much-prized 

 Siberian "fir" or spruce (Picea obovata), the Siberian 

 Pichta or silver fir {Abies sibirica), and the still more 

 valuable Siberian larch {Larix sibirica). On sandy 

 soils pine woods are occasionally found. In the 

 swampy zone the character of the forest changes. The 

 larch disappears, and the spruce predominates with 

 an admixture of deciduous species such as the birch, 

 aspen, and alder. The most wide-spread type of 

 forest in Western Siberia is a mixture of common 

 and Siberian spruces. This type is interrupted here 

 and there by the so-called urmani, a local name for 

 mixed deciduous and non-deciduous forest in which 

 the spruce and cembran pine predominate. In the 

 Government of Tobolsk this tirmani type of forest 



