TY JOUR TI VARIABILITY OF THE HARDNESS OF PINE WOOD DAMAGED BY STRONG GRASSROOTS AND RAMPANT RIDING FIRE KW pine wood KW static end hardness KW fire KW tarring of wood KW trunk KW core KW sapwood JO Forestry Engineering Journal AU Snegireva, S.N. AU Platonov, A.D. AU Kiseleva, A.V. AU Kantieva, E.V. PY 2022 IS 11 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov