Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Effect of climatic factors on the dynamics of radial increments of Norway spruce, European beech and sessile oak. | JOURNAL OF FOREST SCIENCE 57 2011 7 293-302 Effect of climatic factors on the dynamics of radial increments of Norway spruce European beech and sessile oak R. Petrás J. Mecko National Forest Centre - Forest Research Institute in Zvolen Zvolen Slovakia ABSTRACT Correlations of increment indexes with average monthly temperatures and total monthly precipitation were studied on annual ring series of 455 trees of Norway spruce Picea abies L. Karst. sessile oak Quercus petrea Liebl. and European beech Fagus sylvatica L. . Data on precipitation from the period 1901-2005 and on temperatures from the period 1931-2005 were used. Statistically significant dependences with correlation coefficients in the range of were confirmed. All tree species react positively to precipitation mainly in June and July. An increase in precipitation by 1 mm when compared with the long-term average results in an increase in increment index of spruce almost by . This index in oak and beech increases only by a half value of the value for spruce. Precipitation from the second half of the vegetation period of the previous year is also important. Higher temperatures during the vegetation period affect increment changes mostly negatively. With temperature increase by 1 C when compared with the long-term average the increment index of trees decreases by about 1-2 . Keywords annual ring analysis climatic factors radial increments European beech sessile oak Norway spruce Slovakia Diameter and height increments are typical growth characteristics of trees and they have a seasonal character in our temperate climatic zone. Individual dispositions of tree site and climatic conditions of each tree contribute to their formation. Possible damage to trees and change in the growth conditions are frequent reasons for increment changes. It has been confirmed by many results of research published recently . in relation with damage to forests by air pollutants and emissions as well as the results of .