Linear scales and antifragility

This article examines the limitations of linear assessment scales currently used in arboricultural practice to evaluate the mechanical state of trees, and proposes a paradigm shift towards dynamic scales and clinical predictive scores. Drawing on Nassim Taleb's concept of antifragility, the author demonstrates that trees are not fragile systems but antifragile ones: they improve their structural resistance in response to mechanical stress, particularly through thigmomorphogenesis. This challenges the validity of linear grading scales, which fail to account for the non-linear, complex responses of living systems. The article argues that combined multiparameter approaches, such as clinical predictive rules already widely used in medicine, offer a more accurate and reproducible method for assessing tree safety factors. Published in ARB Magazine, Issue 202, Autumn 2023, The Arboricultural Association. Mots-clés : linear scales antifragility tree mechanical assessment clinical predictive rules safety factorstructural diagnosis thigmomorphogenesis tree risk assessment clinical arboriculture dynamic scale