Abstract
In two stands of Norway spruce (Picea abies (L.) Karst.), planted in 1952 and 1929 in Yair Hill Forest and Glentress Forest, Borders Region, two per cent of the trees examined in 1983 had extraction damage on stems and superficial roots. Extraction wounds were 4 and 8 years old respectively and ranged in size from 52 to 1099 cm2. Infection frequency of the damaged trees was 47 per cent and 54 per cent respectively. Stereum sanguinolentum was the most common fungus isolated, accompanied by Trichoderma viride Fr; Chaetomium cochlioides Palliser and Heterobasidion annosum (Fr.) Bref. The frequency of isolation of S. sanguinolentum increased progressively in samples taken from the outside of stems inwards, whereas the other microorganisms present showed the opposite pattern. In four trees, T. viride overgrew S. sanguinolentum in the the decay columns. Positive correlations were demonstrated between surface area of wounds and vertical extension of decay, tree volume and decay volume, and diameter of stem at breast height (DBH) and decay volume; whereas a negative correlation occurred between number of growth rings per 5 cm (measured inwards from the outside of the bole) and radial penetration of decay. The results confirm the importance of S. sanguinolentum as a wound pathogen.