Relationships between crown projected area and components of above-ground biomass in Norway spruce trees in even-aged stands: Empirical results and their interpretation

Sample tree material was reanalyzed in order to study the relationships between horizontal crown projected area and components of above-ground biomass in Norway spruce (Picea abies (L.) Karst.) trees growing in even-aged stands. The needle mass of dominant trees increased linearly with the increase in crown projected area, but in co-dominant and dominanted trees the increase in needle mass levelled off toward larger crown projected areas. The branch mass of dominant and co-dominant trees accumulated faster than linearly with increasing crown projected area, whereas in dominated trees an approximately linear relationship existed between these two variables. The increase in needle and branch mass per unit increase in crown projected area was highest in dominant trees and decreased to co-dominant and dominated trees, i.e. with tree position in the canopy. The stem mass accumulated obviously faster than linearly and similarly in all tree classes with the increase in crown projected area. The narrow crown shape indicated a high density of all components of above-ground biomass per unit of crown projected area.