Barna M.: Impact of shelterwood cutting on twig growth in predominant beech trees (Fagus sylvatica L.). Ekológia (Bratislava), Vol. 19, No. 4, 341-353, 2000. This work deals with effect of cutting operation on annual length increment for predominant trees. Partial plots (PPs) in a beech ecosystem with various stocking density (0.3, 0.5, 0.7, 0.9) had resulted due to improvement cutting. Crowns of trees responded to the cutting through variability in the length growth of their twigs. Detailed research on beech crown response (dynamics of variance in growth increments) to the cutting was performed 1825 annual length increments sampled from 4 predominant trees. After the evaluation of annual length increments from within 1980 to 1997, using multiple comparison of mean values (LSD test), this interval was divided into 3 growth periods (primary period, period of accelerated growth, period of depression and normalization). The results show the period of accelerated growth lasting for 3 years in the upper third of the crown, and 4 years in both the middle and the lower third of the crown, and also that this process was followed by a decrease. Twigs in each third of the crown responded to cutting by means of enhanced length increment always in the 2nd vegetation period after the realization of cutting. The greatest increments in all the three portions of the crown during the period of accelerated growth were recorded on the sample tree situated on the PP with a stocking of 0.5. The lower third of the crown was the most sensitive to the cutting intensity with this factor showing only little significance for the middle third of the crown. This points to the fact that the greatest variances in increment growth between PPs could be observed in the lower third of crowns, and that the least variance was recorded for the middle third of crowns. The growth period influence on the increment length is most remarkably reflected within the upper third of crown, being less remarkable in the lower and the minimum in the middle crown-third. The influence of temperature increased with position within the crown (lower third of the crown - least significant, middle third of the crown - more significant, etc.) The influence of precipitation effected the crown in the opposite order with the greatest effect on the lower third and the highest effect on upper portions.