THE NATURAL REGENERATION OF PICEA OBAVATA LEDEB. AND ABIES SIBIRICA LEDEB. OF CENOPOPULATIONS IN LONG-TERM SECONDARY BIRCH FORESTS OF THE SOUTHERN URALS MOUNTAINS
For the western low mountains of the Southen Urals the age structure of Picea obavata and Abies sibirica cenopopulations in long-term secondary birch forests (20-100 years old) was analysed. It is revealed hat, the dark-coniferous species age structure is disturbed on all the distance of the long-term secondary birch forests formation: the new generations of Picea obavata and Abies sibirica are appearing not always, the separate small generation are often registered. The Picea obavata and Abies sibirica of prior generation in basic layer stand are the source of sowing. Dark-coniferous species predominance restoration is very much slow and is possible after natural disintegration of birch forest (120 years old).