PROCESSING OF LOGGING RESIDUES AND ITS IMPACT ON HERBACEOUS AND SHRUB LAYER ON NATURAL PINE SITES

The aim of this study was to analyse the impact of different logging residues treatments on herbaceous and shrub layer 5 years after the final harvest. Characteristics of vegetation were assessed on three research localities, where three variants of manipulation and utilization of logging residues were applied - (i) burning of logging residues on the site, (ii) complete removal of logging residues, and (iii) chipping of wood residues on the site. Further, a large-scale ploughing of soil was performed in all treatments. Although natural regeneration is dominated by pine (Pinus sylvestris L.) (58% - up to 70 000 pc/ha), the rate of birch (Betula pendula Roth) amounted to 37% (up to 44 000 pc/ha). With exception of wet sites covered by Calamagrostis epigejos L., birch was the most important competitor to pine with very fast height growth (average birch height h = 86.35 +/- 43.58 SD compared to average pine height h = 18.27 +/- 15.15). Although it seems that ash distribution as a result of burning of logging residues to some extent supported birch regeneration, the factor of treatment was of lesser importance than that of the locality. The results also showed that after five years the development of herbal and shrub layer is still in progress, when especially the coverage of small shrubs is still much lower compared to closed forest conditions.