TY JOUR TI GROWTH PECULIARITIES OF THE DROOPING BIRCH (BETULA PENDULA ROTH.) IN PURE AND MIXED PHYTOCENOSIS ON THE SOUTHERN CHENOZEM IN THE STEPPE CONDITIONS KW drooping birch (Betula pendula Roth.) KW pure and mixed plantings KW artificial phytocenosis KW south-ernchernozem KW growthlinear indicators JO Bulletin of KSAU AU Kovylina, O.P. AU Kovylin, N.V. AU Zhikhar, A.A. PY 2015 IS PB Krasnoyarsk State Agrarian University