AbstractWhen the sapwood of Eucalyptus maculata Hook, was tested between 7 and 240 days after injury, increases were generally detected in both the concentration of phenols and activity of phenol oxidizing enzymes (peroxidase, tyrosinase and laccase). This effect was most pronounced in a narrow ‘marginal zone’ at the boundary of healthy and injured/infected tissues. It is probable that one or more enzymes stimulate production of antimicrobial phenols contributing to effective compartmenalization of microbial invasion in the sapwood.