Sygnał klimatyczny w seriach przyrostów rocznych świerków z regla dolnego oraz górnego w Tatrach

The study analysed short−term rhythm of radial increments of spruces from different elevations and their climate drivers. Two Norway spruce stands were chosen at the lower and upper montane forest belt in Roztoka Valley (DR) (1000−1050 m asl, 49°13′N, 20°04′E) and in Hala Gąsienicowa (HG) (1500−1550 m asl, 49°13′N, 20°04′E). 20 trees were sampled and one increment core was taken per tree. The sampled trees were dominant or co−dominant individuals without visible damage. To remove the age trend, the tree−ring widths values were standardized to annual sensitivity indices. Principal components analysis, bootstrapped correlation and pointer years analysis were used to classify sensitivity of investigated series and identify the climate factors, which determined annual variability of the radial increments. Pointer years were also determined by using interval trend method. The first principal component (PC1) accounts for 39% of the variance among all tree−ring series. The second component (PC2) accounts for 15% of the variance among the tree−ring series and divides the series into two groups. This grouping seems to express the lower and higher locations of the sites. The sensitivity series of spruces from both sites had different as well as similar features. These differences resulted from different tree's reaction to temperature in early spring and precipitation in spring and summer. The similarity of increment reactions of spruce from both sites was caused by their similar sensitivity to sunshine duration and precipitation in January, temperature in June and July, sunshine duration in June. Cluster analysis confirmed the impact of the climatic factors on differences of increment reactions of spruces. A number of the pointer years was higher at site located in the upper montane forest belt. Their chronology also consisted a stronger climatic signal. The climatic sensitivity which was specificity for a given climatic belt was recorded into individual tree series. For that reason, the tree−ring width series of trees are useful in the estimate of a climate−increment relationship. They can also be used to dividing dendroclimatic belts.