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The Quantified Tree Risk Assessment Method

Tree safety management is a matter of limiting the risk of harm from tree failure whilst maintaining the benefits conferred by trees. Although it may seem counter intuitive, the condition of trees should not be the first consideration. Instead, tree managers should consider first the usage of the land on which the trees stand, which in turn will inform the process of assessing the trees.

photograph - crushed car 2The Quantified Tree Risk Assessment (QTRA) system applies established and accepted risk management principles to tree safety management.

QTRA moves the management of the risk from falling trees away from labelling trees as either ‘safe’ or ‘unsafe’ and thereby away from requiring definitive judgements of either tree surveyors or tree managers. Instead, QTRA quantifies the risk of significant harm from tree failure in a way that enables tree managers to balance safety with tree value.