Wood is a material with unique properties that contribute to its wide use as a raw material for various types of industries. Different quality requirements are imposed on the raw materialdepending on the material or wood product. However, physical and mechanical properties of wood are not homogenousalong the radius and height of the trunk and depend on the species, location in the trunk and growing conditions. The aim of this research is to study the variability of porosity and density of Scots pine (Pinus sylvestris L.) wood in a tree trunk growing in dry forests of the forest-steppe zone of the Russian Federation. The studies were carried out on wood cuts, sawn at different trunk heights. The change in the density of pine wood along the height of the trunk by 1.43% for each meter has been established. The wood porosity increases from the butt to the top by an average of 5.5%. New information about the variability of wood properties makes it possible to rationally and reasonably approach the choice of raw materials for obtaining materials with specified performance characteristics.

Fumed oak wood is valuable and one of the most environmentally friendly natural materials. As a result of a long stay of wood in flowing river water and in contact with bottom soil without air access, an individual process of staining of each trunk occurs. It consists in changing the chemical composition of the wood. The wood acquires increased strength and a beautiful color scheme. It is established that the degree of coloring of fumed oak wood depends on the amount of iron oxides in it (Fe2O3). There are industrial stocks of this wood in the Russian Federation. Drying process is one of the key technological operations. The most common methods of fumed oak wood drying are convective-atmospheric and convective-thermal ones. They have long duration, and the number of defects in warping and cracking reaches 30-40%. In this work, the drying of fumed oak wood by various methods has been investigated. It has been established that shrinkage of fumed oak wood is 1.5-2.0 times more than of natural oak woo. Preliminary thermochemical treatment enables to reduce the volumetric shrinkage of wood by 25%. An analysis of the color change of fumed oak wood depending on the conditions of wood staining in the river Voronezh has been made. Determination of the shrinkage quality and size is necessary to justify the allowances for obtaining sizes of lumber when cutting round wood. The studies performed will allow the rational and efficient use of valuable and unique oak wood

The article presents the results of experimental studies of the effect of forest fires on the structure of the annual layer and its parts of pine wood. The harmful effect of forest fires is expressed, first of all, in the direct destruction and damage of wood by fire. Wood raw materials harvested from various growing conditions differ in a number of qualitative indicators. In the practical use of wood damaged by fire, the characteristics of the macrostructure are used for a preliminary assessment of its quality, calculated for the most part according to the parameters of the annual layer. The revealed changes in the pre-fire and post-fire growth of wood will allow us to judge the quality and vital activity of pine stands growing in forest-steppe conditions.

Wood is a material characterized by anisotropy of structure and variability of properties in the tree trunk. The indicators of wood properties can be predicted by the density value. Wood density formation in a tree trunk is influenced by many factors. The most important are: age changes, the position in the trunk and the impact of the environment. The purpose of this study is to establish the regularity of wood density formation along the trunk radius. Regularity is based on growing conditions and latitude zoning for Scots pine (Pinus sylvestris L.) and altitude zoning for European chestnut (Castanea sativa Mill.). The studies have been performed on cores including wood sections from bark to core obtained using coring instrument. Density of each annual layer by measuring buoyancy force of specimens immersed in a liquid was determined. The formation features and periods of the maximum density of pine and chestnut wood along the trunk radius were established based on latitudinal and altitudinal zoning of wood in the temperate continental climate of the European part of Russia.

доктор технических наук, доцент А. Д. Платонов 1 старший преподаватель, М. А. Михеевская 2 кандидат биологических наук, доцент С. Н. Снегирева 1 кандидат технических наук, доцент Т. К. Курьянова 1 кандидат биологических наук, доцент А. В. Киселева 1 директор УОЛ, А.Н. Топчеев 3 Деревопереработка.