the larch wood is dry and hght, without throwing any obstacles in the way of the 

 traveller. The thin branches and narrow leaves allow the rays of the sun and the 

 light to pass through, and in the soil, abounding in humus, formed by the leaves, which 

 are shed yearly, there is to be found a luxuriant flora. The larch may also occur 

 in moister places, but here, as it generally appears, more sporadically together with the 

 spruce, the silver-fir, and the cedar. In alpine regions it ascends as high up as the 

 tree limit, which it forms together with the cedar. The larch being thus especially dis- 

 tributed in dry places, it constitutes, with the birch and the aspen, the greater part of the 

 trees to be found on the dry open wood-steppe, which form the transition zone be- 

 tween the taiga and the steppe region, and are covered with dry open woods with lar- 

 ger and smaller open steppe-like areas between them. 



As mentioned before, the virgin forest begins for good at Kushabar, lying at a 

 height of about 320 m. above sea-level. The soil here is rather sandy, forming a narrow 

 transition zone chiefly consisting of Pinus silvestris, in a less degree harix sibirica, 

 and various foliferous trees, especially poplars and birches. When growing densely, the 

 trees attain here a height of about 40 m. and even more, while in open wood the height 

 does not generally exceed 30—40 m. but in return with somewhat thicker trunks. The 

 scarcity of young conifers in the outskirts of the forests is noticeable, the younger gene- 

 ration being chiefly foliferous trees, which seems to indicate that the conifers are gra- 

 dually being reduced, probably owing to ttie constantly increasing dryness in these regi- 

 ons. Later on I will return to this question. The vegetation making up the ground flora 

 here is also still intermixed with some steppe forms. But gradually the forest of conifers 



Fig. 25. From the subalpine tracts in the Sayansk district. Open 

 moist hillside chiefly grown with Veratriim album, Aquilegia 

 sibirica, and Pedicularis resapinatd. 



48 



