The Traits and Effect of Thinning in Mixed Oak-Beech Stands

1991

3 Abb., 4 Tab., 16 Lit. Ang.

Unselbständiges Werk

6753

200062141

The quantitative and qualitative effect of the positive crown thinning was studied on the series of research areas in a mixed oak-beech stand. A different target proportion of oak and beech was asserted through the corresponding ratio of both the tree species in the number and volume of trees selected for cutting (BR). The high intensity of thinning intervention was chosen (20-25% out of stocks). The intervals between the previous 4 thinning interventions done during 19 years were graded into 4, 5, 10 years. The natural stocking in the middle of intervals did not fall under the critical value (0.65) even after the 4th intervention. The process of differentiation and autoreduction during the young growth and small pole stage caused the formation of numerous lower beech layer of divergent height, and oak kept its codominant position up to the age of 50 years. The oak has substantially better mean stem quality in comparison with beech and that is why even a lower number of codominant oaks enables a better and more uniform choice of trees for cutting. More intensive thinning, consistently aimed at the support of 300 trees selected for cutting, contributed to the increase of the volume production by 6-8% in comparison with the control area, and that of the part of volume production with the highest stem quality by 20-30%. The sum of thinning volumes practically exhausted the periodic increment of these 19 years so that the stock on the areas after the 4th intervention made only 49-55% of the stock on the control area.