Tree Quality and Forest Structure Changes in the First Stage of Conversion of High Forest Into Coppice-with-standards

The work is aimed on evaluation of the effect of thinning on stand structure and changes of the quality of the trees under strong thinning measures in the forest stand with prevailing Quercus petraea in South Moravian Region of the Czech Republic. Three thinning variants with 100, 140 and 180 remaining trees per hectare were applied in four replications to simulate structure of a coppice-with-standards forest on a four hectare plot of high forest. On average, the implemented thinning reduced the total tree number from 717 to 140 individuals per hectare. After the thinning, the ratio of potential standards according to stories (the youngest, medium and the oldest) was 68:29:3, which corresponds with 46:44:10 ratio according to the volume. An average of 70-83% of the volume (76-85% of trees) was harvested in individual cells with different thinning variants. Relative frequencies of potential standards in quality score classes (A:B:C) were balanced and corresponded to the mean ratio of 11:49:40. The relative distribution of timber volume in score classes was also balanced and corresponded on average to the final ratio of 22:46:32. After the thinning it almost reached the generally recommended diameter distribution of standards in a coppice-with-standards. So far the applied measures did not significantly increase the overall quality of the remaining tree stand.