Analysis of the morphology and sizes of annual growth rings of wood by means of technical vision gives a lot of information about the climatic, ecological and other conditions of plant growth. However, optical methods do not allow assessing the physical, in particular micro- and macro-mechanical properties of wood in each year of growth and, moreover, within each growing season.
The paper proposes a quantitative method for assessing Young's modulus and wood hardness with a resolution from units of nm to tens of microns by the method of automated mapping of these characteristics using an atomic force microscope operating in a contact mode or a nanoindentometer. The latter is specially designed for continuous recording of the immersion depth of the diamond probe and the penetration resistance force, which, after processing the loading diagrams, makes it possible to determine up to 5 independent local characteristics of the material on a nano- or microscale. Modern nanoindentometers allow in automatic mode to make several thousand individual measurements at programmed points and then build a map of local mechanical properties.
The analysis of such maps makes it possible to determine with high accuracy the position and thickness of annual growth rings and layers of early and late wood, the course of changes in mechanical properties within each annual ring, and to link these dependencies with climatic and ecological growing conditions.
Examples of such analysis of maps of mechanical properties on cross sections of pine (Pinus sylvestris L.), linden (Tilia cordata Mill.), Oak (Quercus robur L.) and birch (Betula pendula Roth) are given.