BROADLEAVED TREE TRUNKS CHARRING DURING FOREST FIRES WITHIN THE UKRAINIAN ROZTOCHYA

Abstract

Introduction. On the territory of Ukrainian Roztochya and Male Polissya (Zhovkva part of Roztochya included) fires often occur in natural ecosystems – forest fires, meadow vegetation burning, stubble, landfills, and peatlands. Such fires, in addition to the destruction of property, cause significant emissions of incomplete combustion products and smoke into the air. Charring of broadleaved species, along with conifers, needs more detailed research, as the territory of the Ukrainian Roztochya is dominated by hornbeam-oak-pine, mixed oak, and beech forests.
Aim. The object of the paper is to investigate the degree of tree trunks charring of the main forest-forming species in the Ukrainian Roztochya during forest fires based on experimental data.
Research methods. Freshly cut trees were exposed to heating for 10 minutes, at periods of 1 minute, 3, and 5 minutes, checking the degree of damage to the trunk (charring, mm). Repeatability of the experiment – three times. Basing on received data the charring of broadleaved tree trunks in the Ukrainian Roztocze was determined. The flame temperature was measured by a GM1150A non-contact pyrometer. The level of burnout was measured by a ruler made following GOST 17435-72. A stopwatch was used to record the time of burning. Results and discussion. The experiments were performed in the fresh air under close-to-natural conditions. The fire source was an artificial open flame. Freshly cut tree trunks were installed vertically, right in the burning zone. Cutting residues, fallen dry leaves, straw, dry grass was used as flammable material. It was found that the lowest degree of charring is inherent to oak, which has burned by 38 mm during 10 minutes (with log thickness of 124 mm). Species such as hornbeam and maple completely burned out in 10 minutes (in diameters of 129 mm and 140 mm).
Conclusions. Investigations of temperature effects on the main forest-forming species of the region have shown that they all differ in charring during forest fires. Three species grown in Ukrainian Roztochya were selected – hornbeam (Carpinus betulus), oak (Quercus robur), and maple (Acer platanoides). To prevent fires in forests, fire lanes should be planned with oak plantations on the edge of the forest.