In the integrated recovery of stem and crown, the proportions of the different tree components in the raw material must be known. The Finnish Forest Research Institute carried out a study on the quantity, composition and vertical distribution of crown mass in Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and mixed birch (Betula pendula and B. pubescens) at the harvesting phase. The research material was composed exclusively of trees which were to be removed from the stand during the coming logging season in accordance with the Finnish forest management principles. Altogether, the crown mass of 6500 trees was measured by 2-meter tree sections. External tree characteristics such as breast height diameter, tree height and crown ratio explained best the tree-to-tree variation of crown and needle mass. As compared to dry stem mass, the amount of dry needle mass was in southern Finland in pine trees harvested from first thinnings 10.4% from other thinnings 5.7% and from final cuttings 4.2%. The corresponding figures were for spruce 19.1%, 14.7% and 15.0%. A simple way to reduce needle removal in conjunction with whole-tree logging is topping the trees on site. In first thinnings 52% of pine needles and 34% of spruce needles remain in a 3 m top which corresponds to 5-6 cm top diameter of pulpwood.
