Klimatyczne przyczyny krótkookresowych reakcji przyrostowych jodły pospolitej z pogórza oraz regla dolnego

The aim of this study was to i) determine similarities and differences in the increment reaction of silver firs growing at different elevation, ii) identify climatic factors, which caused these response, and iii) determine dendroclimatic zones and identify a site, where a tree grew on the basis of tree−ring widths series. Studied stands were located in the Ustroń Forest District at the elevation of: 500−550 m a.s.l. (foothill zone, 18°59‵ E, 49°43‵ N) and 800−850 m a.s.l. (lower montane forest zone, 18°58‵ E, 49°43‵ N). In each stand 20 dominant firs were selected and one increment core per tree was taken. Tree−ring widths (fig. 1) were transformed into annual sensitivity index (fig. 2). Principal component analysis was used to reduce a number of original variables and classify the tree−ring series. Response function analysis was used to determine climate−radial increment relationships. The standardized series of firs on both sites were different in terms of the climate influence (fig. 3). The analysed trees responded differently to solar and thermal conditions in previous autumn and current summer as well as to pluvial conditions at the beginning of winter and in the second half of summer. The investigated firs had also common increment characteristics. The trees from both sites responded similarly to thermal, solar and pluvial conditions in February, solar and pluvial conditions in May and temperature in winter and summer (fig. 4). Climatic signal of each elevation zone was recorded by each tree and depended on the climatic conditions in given area. On the basis of standardized tree−ring series, dendroclimatic regionalization can be created and the stand, where a tree grew, can be identified.