Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

Abstract The primary objective of the research project was to determine the variability of the taxation characters of pine stands during individual cycles of forest management work in the period extending from 1963 to 2004. The authors assessed changes in the forest species composition which took place in the Zielonka Experimental Forest District, especially, the proportion of Scots pine. It is evident from the performed analyses that the share of pine in the discussed object decreased during the examined period of time by nearly 7% and, in 2004, it reached the level of 82.7%. The oak increased its share from 5.1% of the forest area in 1963 to 12.3% in 2004. The obtained results corroborate a systematic increase of the stand current increment and volume. Changes in the proportion of forest sites (19% in 1963 and 78% in 2004) indicate that there is a need for the modification in the ways of forest management, especially in the case of pine stands which are artificial and unsuitable for the site.