QUALIMETRY OF FOREST TREES 1. OVERVIEW OF NON-DESTRUCTIVE TESTING METHODS

When studying the biological productivity of forests and developing standards for accounting for all components of biomass, it is necessary to know the laws of the dynamics of the wood density of growing trees as their key environmental characteristics that require the use of non-destructive methods. The pilodyn method, as one of the simplest and most accessible, is in demand in breeding programs, but the selection based on the density indicator obtained by the pilodyn tester was not effective for all tree species, and the density variability explained by this method varies in the range from 27 to 92 %. Qualimetry by the method of wood drilling resistance based on a resistograph, as a more sensitive device compared to a pilodyn tester, has also been widely used in breeding programs, but both methods are based on local probing, and its extrapolation to the entire tree gives biases of estimates. The use of the rigidimeter design does not have the drawback inherent in the two methods mentioned above. But, the method proved to be relatively time-consuming to perform multiple measurements. The acoustic method for assessing the modulus of elasticity and density of wood is sensitive to the presence of wood defects and allows you to remove the contradiction of selection targets aimed at simultaneously increasing the growth rate and density of wood. Radiation methods require the use of expensive equipment and successfully register the intra-ring density. The advantage of NIR-spectroscopy over all other methods is the ability to evaluate the chemistry of wood and the yield of cellulose, but it does not give a direct assessment and requires special calibration. Thus, any technique has its limitations, and it is important to be able to choose the technique that is most suitable for a particular.

wood qualimetry, growing trees, pilodyn-tester, resistograph, rigidimeter, acoustic and radiation methods, NIR-spectroscopy