Influence of weather and day length on intra-seasonal growth of Norway spruce (<i>Picea abies</i>) and European beech (<i>Fagus sylvatica</i>) in a natural montane forest

Intra-seasonal growth responses of co-occurring European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) to weather variability in montane forests can provide useful information on their future trends. To improve predictions, we aimed identify (i) the main seasonal windows during which influences tree-ring growth, (ii) species-specific differences response fluctuations, (iii) teleconnections remote sites Western Carpathians. We monitored intra-seasonal dynamics based proxies extracted signals detected by high-resolution dendrometers transition zone between altitudinal belt. Over 12 consecutive seasons natural forest (1350 m a.s.l.), part (68% 10 July) (95% 26 August) annual increment was under prevailing influence temperature. After this, precipitation pattern (regarding spruce) day length became most influential variables deceleration cessation growth. In addition, synchronous patterns with Carpathians were found. The results emphasize importance studying shorter-term fluctuations season. Our findings suggest that tends be less temperature-demanding more drought-sensitive than beech, may favor over climate.