This undergraduate thesis analyses the increment of Norway spruce (Picea abies) depending on age, canopy density and growth conditions in the Pokljuka and Jelovica area. In order to do this we set up 18 research plots. Each of the analysed trees was bored at breast height (1.3 m from the ground) to analyse the growth in the last 30 years. Five dominant trees per plot, on the other hand, had a sample taken to the pith. The results showed that there are hardly any differences between the developmental phase regarding diameter increment and that adult spruces (mature tree stands) respond to thinning by increasing growth, as well. There were no differences in the diameter increment for varying degrees of crown density in any of the developmental phases or for the whole stand canopy population. The results also demonstrated that the current increment in the volume of the stands decreases linearly depending on the density of the tree canopy stand and that the responsiveness of the basal area increment on the degree of competition from other trees actually increases with age.
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