DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 7-8/2022 str. 50 <-- 50 --> PDF |
was confirmed by autocorrelation coefficients close to zero (from -0.007 to 0.004). The mean tree diameter of Austrian pine trees per sampling site ranged from 41.7 to 50.4 cm and the mean height from 18.3 to 28.3 m. The average tree age ranged from 78 to 140 years. The arithmetic mean of all the empirical series of tree-ring widths ranged from 1.36 (Site 2) to 2.09 (Site 4) and the serial intercorrelation of the empirical tree-ring widths from 0.391 (Site 5) to 0.560 (Site 4). The values of the mean sensitivity ranged from 0.243 (Site 2 and Site 3) to 0.264 (Site 5). The standard deviation of the filtered series ranged from 0.295 to 0.339, while the autocorrelation coefficients close to zero (ranging from 0.006 to 0.013) indicated higher sensitivity to environmental changes (Table 3). The average tree-ring width (TRW) series for Scots and Austrian pines per sampling site (Figure 3) show that the age-related growth trend is clearly observed for both species at all sites except Site 4. It is a site with the oldest individual trees of both species and the worst site conditions according to the local site quality classification. The removal of age-related growth trends, i.e. the standardisation of the raw tree-ring width series was performed in the ARSTAN software. Raw ring-width series were detrended using cubic smoothing splines (Cook and Peters 1981) with a 50% frequency response cut-off. The adequacy of merging four sites’ chronologies into one master chronology was determined based on t-values (tBP) and GLK between site chronologies. Between sites with Scots pine trees GLK were statistically significant and tBP values |