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The research was conducted in selected 80- to 110-year-old spruce stands in the south-eastern part of the Českomoravská Upland at altitudes from 350 m a.s.l. to 465 m a.s.l. The regional standard tree-ring chronology shows very low increments for years 1974, 1976 and 1992. After 1992, there is a sharp rise in increments with a climax in 1997. Afterwards, increments gradually decrease, reaching minima in 2003 and 2008. The years with low increments were also confirmed by the analysis of negative pointer years when over 80% of the analysed trees responded by a sharp decrease in increment, mainly in years 1976 and 1992. We can usually find values of monthly precipitation or monthly temperature average which can explain or help explain these falls in the radial growth. The correlations of diameter increments with average monthly precipitation gain only positive statistically significant values, namely for the months of May, June, July and August of the particular year. The correlations of diameter increments with average monthly temperatures gain only negative statistically significant values, namely for the months of June, July and September of the previous year and January and August of the particular year. In the examined area there is a significant negative correlation between average temperatures and monthly precipitation in July, August and September. The results of the habitual diagnostics show that with respect to the climatic conditions the health condition of the monitored stands is relatively good. On average, the defoliation does not exceed the values ascertained in different territories of the Czech Republic. [ABSTRACT FROM AUTHOR]

The aims of the study were to determine the effect of temperatures and precipitation on the ring width and to compare the results with the results of previous studies conducted in other mountain ranges of the Czech Republic. The research was performedin the central part of the Ceskomoravská Uplandin the vicinity of Herálec municipality in selected 70- up to 110-year-old spruce stands at altitudes from 680ma.s.l. to 779 m a.s.l. Measuring of tree-ring widths and synchronization of individual ring series were conducted in PAST4. The age trend was removed by ARSTAN and climatic effects were modelled in Dendro Clim 2002. The correlation of tree-ring width with monthly precipitation is positive and statistically significant for July of the previous year andfor the entire summer periodfrom June to September of the current year. The correlation of tree-ring width with mean monthly temperatures is negative andstatistically significant for July and Septem - ber andpositive andstatistically significant for October of the previous year. Negative correlation was also foundfor temperatures of the entire summer periodfrom June to September of the previous year. The regional tree-ring chronology mainly shows two periods of highly reduced increment: from 1992 to 1996 and from 2003 to the end of the analysed period. The results thus confirm the hypothesis that the tree-ring width is in positive correlation with summer precipitation andnegative correlation with summer temperatures. Also the results of the habitual diagnostics have shown a relatively low degree of crown transformation which indicates a weak or short-term stress load. [ABSTRACT FROM AUTHOR]

Climatic parameters are the main environmental factors affecting tree growth. The main aim of the presented study was to determine whether different oak species growing under contrasting environmental conditions show different sensitivity to climatic parameters. Four oak stands with Quercus robur, Quercus petraea, Quercus polycarpa and Quercus dalechampii growing in the same area were evaluated. Standard dendrochronological methods were used for sample preparation, ring width measurements, cross-dating, chronology development, and the assessment of growth-climate response patterns. Although the species grew under different environmental conditions, their local tree-ring chronologies are highly correlated. The radial growth responses to climatic parameters differ slightly, but the response depends more on local site conditions than on the oak species. At the same time, the strongest correlations between radial growth and climatic parameters were identical among species and sites. The amount of water available in the soil was the main climate-dependent factor limiting radial growth. Approximately since the 1990s, the distribution of rainfalls within the growing season has changed at the expense of spring precipitation. The significance of relative soil moisture content during spring for oak growth increased and the significance of summer values decreased. [ABSTRACT FROM AUTHOR]