The role of the pyrogenic factor in the productivity and dynamics of the pine forests in Transbaikalia

Peculiarities of the dynamics and productivity of the pine forests growing under the conditions of the Transbaikalia arid climate are considered. Their high inflammability is noted. Fires sharpen the limiting role of moisture in tree growth. The post-fire annual ring fluctuations on longitudinal sections of young pines are illustrated. Outward diagnostic signs characterizing the xylogenesis state in trees damaged by fire have been analyzed: the char height on trunks, thermal damage to crowns, reduction and change in the tint of needle coloring. The process of digression dynamics of pyrogenic tree stands has been traced. Their reparation potential has been found to become weaker with ageing. As a result of the permanent effect of the pyrogenic factor, the productivity of pine forests in Transbaikalia is 1.5–2 times lower than of those in Priangarie.