EN
The study examined the sensitivity to air temperature and precipitation of 18 Scots pine stands growing at dry and boggy coniferous forest habitats in Białowieska (BIA), Świętokrzyska (SWI) and Solska (SOL) Primeval Forests. At each plot, 20 healthy and undamaged pine trees were sampled (two cores per tree). The cores were scanned and the CooRecorder & CDendro 7.8 image analysis software was used for measuring tree−ring widths. The standardization of the individual tree−ring series for removing no−climatic variations was employed. For each stand the index chronology was constructed on the basis of individual index series. The grouping of site chronologies was performed by the cluster analysis. The principal components analysis was applied to identify common characteristics of chronologies. Correlation analysis was used in order to identify the climatic elements described by the main components. The first component (PC1) highlighted the variability common to all chronologies and described the average air temperature in February, March and May, and the total precipitation in June and July in the year of tree−ring formation. Regardless of the region and the site habitat, pines increased the radial increment when winter was warm and short, spring was cold and summer was abundant in precipitation. The PC3 distinguished pines growing in BIA. Scots pine increased radial growth when it was cold in June. The PC2 described climatic elements whose influence on the radial growth of Scots pine in both habitats was different. Therefore, the PC2 indicates that the pines from BIA growing at boggy and dry habitats reacted differently to precipitation in February and April. The pines at both these habitats in SOL differed in sensitivity to precipitation in February, May and August, while the trees in SWI only to precipitation in February. The results indicate that differences in climatic conditions between the regions were reflected in the size of the wood formed by the trees. On the other hand, site conditions modify significantly these relations. Therefore, due to the wide geographical range and habitats occupied by Scots pine, the climate−radial increment relationships should be analyzed in detail in any case.