Dendroekologija in les navadne bukve (Fagus sylvatica) v kontekstu podnebnih sprememb

Climate change significantly impacts the growth of European beech (Fagus sylvatica) across its entire natural range. We focused on European beech in Slovenia using a fine-scale approach to study its response to climate variations over the period 1953–2018. High-resolution climate data with both spatial and temporal precision was essential for this research. Therefore, the SLOCLIM dataset was developed, providing daily gridded climate data, including minimum and maximum air temperatures and precipitation from 1950 to 2018. Our research has shown that daily meteorological data exhibit stronger correlations with tree-ring variation than monthly data, which is particularly important for studying the effects of precipitation on tree growth. Using forest inventory data with climate variables, such as spring precipitation and maximum temperatures, revealed the significant influence of climate on beech dominance at the stand level. A network of tree-ring data demonstrated that beech growth in Slovenia declined by 11% in the period 1986–2018 compared to the period 1953–1985. The decline was especially pronounced in the sub-Mediterranean region. Conversely, high-altitude areas showed growth improvements under warming conditions. Daily phenological observations of beech leaf development and senescence in Ljubljana in 2020 revealed intra-species differences and earlier leaf unfolding, which was attributed to a warm winter, and delayed leaf colouring linked to higher summer and autumn temperatures. These findings were further supported by wood anatomy studies conducted on microcores collected from selected sites. This dissertation, based on published articles, provides insights into how European beech, a drought-sensitive species, faces increasing risks under progressive climate change, especially in marginal areas of Slovenia. The collected data and findings were included into a larger research network addressing European beech across its entire natural range.