Assessment of the effect of quality factors on the assortment structure in poplar plantations

Quality factors affecting the assortment quality structure in poplar plantations were researched on nine temporary sample plots in the period 1997-2004, from the aspect of the implementation of roundwood standards. Sample plots were selected depending on the factors, the effect of which was studied. The following factors were researched: clonal species, planting pattern, flood risk, pruning of branches, plantation position and age. The study was performed by the original methodology. Based on the study results, it is concluded that knots have the highest effect on the assortment quality structure in poplar plantations, regardless of the site and stand conditions. Their effect rises significantly with the increase of tree diameter. Also, the analyses show that the number of large and rotten knots on the tree trunk increases considerably with the older age. In the flooded area, the sweep of the lower part of the stem is more intensive and multiple curvatures are frequent on the trees growing immediately along the river, whereas curvature decreases with the distance from the river bank. Based on the study results, it is concluded that the percentage of best quality assortments is considerably reduced by the above wood defects.