Wpływ siedliska i klasy biologicznej drzewa na wydajność korony u sosny zwyczajnej (Pinus sylvestris L.)

Investigations were conducted on 48 Scots pines coming from 16 natural sites in northern Poland. This study was an attempt to analyse relationships between crown parameters of model trees and the stem conduction area in terms of site conditions, age and social diversification of the stand. Analyses showed that there is a strong dependency between crown volume and the volume and area of the xylem (sapwood) responsible for the conduction of water with minerals. Indexes of crown transpiration productivity analysed in the study seem to reflect reliably relations found in the forest phytocenoses and are confirmed in physiological dependencies between the transpiration apparatus, the vascular zone and tree height determined by the occupied social class in the forest community. It may be assumed that sapwood area (physiologically active) is characterised by the variable hydraulic conductivity, probably being the function of age and specific individual characters. In order to maintain the flow of transpiration, optimal for growth conditions, a tree as every living organism exhibits a certain adaptation ability, which makes it possible to meet the above conditions and cope with competition in the community.