The influence of stem girdling on survival and long term health of English oak (Quercus robur L.) and silver birch (Betula pendula Roth.)

Accidental (strimmer, mower) or malicious girdling of ornamental trees is a frequent and underestimated problem in urban landscapes. No guidelines exist for landscape managers on the likelihood of fatal damage according to time of girdle, i.e., season (spring, winter) and extent of girdling. This report investigated the effect of stem girdling (0%, 25%, 50%, 75%, 100%) performed either during winter or spring on semi-mature birch (Betula pendula Roth.) and English oak (Quercus robor L) trees over a five-year period.