HEATING CAPABILITY OF POSTPYROGEN PINE WOOD

The forests of the North are characterized by frequent exposure to ground fires. The study of wood qualities at the burnt areas for its rational use is relevant. The aim of the study was to study the calorific value of Scots pine after a ground fire. The studies were conducted in the Permilovsk, Unsk and Obozersk forest districts of the Arkhangelsk region from 2016-2018. The fire duration in the studied areas was 3-8 years. The calorific value of pine wood in an absolutely dry state was determined using an ABK-1V automated bomb calorimeter. The calorific value of pine wood of post-pyrogenic stands averages from 21,389 J/g to 22,452 J/g. In post-pyrogenic stands, the calorific value of pine soundwood is significantly higher (1331 J/g) compared to sapwood. In pine trees that have dried up after a ground fire and in viable trees that are susceptible to 1-2 stages of decay, the calorific value of wood is at the level of healthy trees. It is 21,182 — 22,590 J/g and 21,521 — 22,394 J/g, respectively. However, sapwood for this category of trees has lower values of 19,648 — 19,873 J/g. The average calorific value of pine wood in plantations not damaged by fires is lower by 658 — 1,721 J/g in comparison with post-pyrogenic ones. For the first time, data on the calorific value of post-pyrogenic wood of trees of different status categories were obtained for the north of the Arkhangelsk region. The calorific value of post-pyrogenic pine wood of different categories of state is characterized by increased values. It allows it to be used as raw material for biofuel.