Changes in the Content of the Main Components of Wood During the Life Cycle of Higher Plants

The influence of both growing conditions and characteristic age features of formation on the intensity of the main components biosynthesis during the plant life cycle causes the heterogeneity of the chemical composition of wood. This fact along with the peculiarities of microstructure ultimately forms the anisotropy of the mechanical properties of wood. Differences in the quantitative content, structure, physicochemical properties of heartwood and sapwood wood must be taken into account in the biorefining of the entire volume of wood. The common pine (Pinus sylvestris) was chosen as the biological object of the study, as one of the main coniferous forest-forming species of the European North. Pine wood cores were used for the analyses. The age dynamics of the content of the main components of pine wood was analyzed by FTIR spectroscopy along with chemical analysis. Macroscopic studies were carried out for the studied samples. The increased content of lignin, as well as total phenolics, was noted for heartwood. According to dendrochronological analysis, heartwood is also characterized by a relatively high content of more lignified late wood. Differences in the content of the carbohydrate component (cellulose and hemicelluloses) are not expressed. Pronounced changes in the content of lignin are due to its high reactivity in redox interactions compared to polysaccharides. The dynamics of changes in the main components content indicates continuous changes in the chemical composition of plants throughout the life cycle, which allows considering the cell wall as a dynamic self-regulating system.