EFFECT OF INTERTREE COMPETITION ON BIOMASS PRODUCTION OF PINUS-SYLVESTRIS (L) HALF-SIB FAMILIES

The effect of competition on biomass production was studied by compari ng five half-sib families and a control lot of young Scots pine (Pinus sylvestris L.) in southern Finland. Stem, branch and needle masses we re clearly affected by competition. However, branch and needle masses were closely related to stem diameter, i.e. the allometric relations b etween the tree parts had not changed. Narrow-crowned families had hig her harvest index and stem increment per crown projection area. Howeve r, differences between families were small compared with variation wit hin families.