The diploma thesis has the character of a dendrochronological study, which was prepared in the growth region of Poľana (Forest Administration Kyslinky) for 3-6. forest vegetation stage and for the three main trees beech, fir and spruce. The measurement, synchronization and detrendization of the obtained borehole samples taken by fieldwork was processed in the work. The following materials had to be performed on the obtained materials: to find out and describe the basic dendrochronological characteristics of borehole samples, quantify incremental changes after 1990 and compare tree growth reactions, all analyzes with respect to different social status (type of stand mixing and stand age) and evaluate incremental changes and derive recommendations for management planning operating practices.