WOOD POROSITY: UNIVERSAL PARAMETER FOR DENDROCLIMATIC ANALYSIS

Annual rings of conifers have traditionally served as a reliable indicator of climatic changes, whereas such analysis methods are poorly developed for diffuse-porous species such as common aspen (Populus tremula L.). In this paper, a new approach, PiC densitometry, based on algorithmic analysis of wood porosity distribution along the annual ring, is proposed. The study was conducted on samples of Scots pine (Pinus sylvestris L.) and aspen. The methodology included measurement of annual ring widths, anatomical analysis of wood microstructure and software image processing to construct porosity profiles. The results revealed fundamental differences in porosity dynamics between species: in pine its value decreases by 70 % from early- to latewood, reflecting a seasonal reduction in water supply, whereas in aspen the change does not exceed 20 %, indicating a stable water demand throughout the season. Dendroclimatic analysis showed that pine radial growth was most sensitive to May-June precipitation, while in aspen, temperatures during the same period were the key factor. The developed PiC densitometry method expands the possibilities of dendrochronological studies, allowing the use of diffuse-porous species for climate reconstruction and assessment of its influence on wood structure.