TY JOUR TI THE ASSESSMENT OF GROWTH OF SPRUCE UNDERGROWTH IN UNEVEN-AGED BILBERRY BIRCH FORESTS OF VOLOGDA REGION KW uneven-aged birch stands KW light mode KW cano-py KW the density of undergrowth KW the growth KW the category of vital state KW crown structure KW crown environmental coefficient JO Bulletin of KSAU AU Zarubina, L.V. AU Snezhko, D.A. AU Pyatovskaya, S.A. PY 2018 IS PB Krasnoyarsk State Agrarian University