Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

Introduction. Scots pine (Pinus sylvestris L.) is a common species found in a wide range of forest site types from dry coniferous forest to mesic mixed broadleaved forest. The highest site index is recorded for pine in mesic mixed coniferous forests and mesic mixed broadleaved forests. Under these site conditions pine trees may also achieve different values of dbh, height and slenderness. Aim of the study. The aim of the study was to determine regularities of Scots pine slenderness at various age and in different growth conditions, i.e. in the oak-pine forest type within mesic mixed coniferous forest and mesic mixed broadleaved forest. Material and methods. Eight study plots of 0.2 ha, located in the Durowo and Goleniów Forest Districts, were selected for the analysis. Stands were characterized by the dominance of pine in the species composition (>90%) and high stocking (>0.9). The age of the pine trees ranged from 31 to 104 years. Results and conclusions. The analysis showed that the average slenderness of pine trees decreases with the age of the stand, regardless of the site conditions. One-way analysis of variance (ANOVA) in terms of site growth conditions at a similar level of slenderness (s > 1.0 m/cm and s <0.8 m/cm) indicated a significant impact of the site within groups with similar average slenderness in both groups.