A linear relationship between the cross sectional area of sapwood at 1·3 m above ground level and the foliage area on eleven trees was determined in a Scots pine ( Pinus sylvestris L.) spacing experiment. The relationship was independent of tree spacing. With increasing tree numbers per unit ground area tree height remained constant, mean tree diameter was less, basal area and volume were greater but leaf area index varied little. A model was used to predict the vertical distribution of foliage area with height for one of the plots from the measurements made on the other three.