title: Forest trees filter chronic wind-signals to acclimate to high winds.
abstract: Controlled experiments have shown that trees acclimate thigmomorphogenetically to wind-loads by sensing their deformation (strain). However, the strain regime in nature is exposed to a full spectrum of winds. We hypothesized that trees avoid overreacting by responding only to winds which bring information on local climate and/or wind exposure. Additionally, competition for light dependent on tree social status also likely affects thigmomorphogenesis. We monitored and manipulated quantitatively the strain regimes of 15 pairs of beech (Fagus sylvatica) trees of contrasting social status in an acclimated stand, and quantified the effects of these regimes on the radial growth over a vegetative season. Trees exposed to artificial bending, the intensity of which corresponds to the strongest wind-induced strains, enhanced their secondary growth by at least 80%. Surprisingly, this reaction was even greater - relatively - for suppressed trees than for dominant ones. Acclimated trees did not sense the different types of wind events in the same way. Daily wind speed peaks due to thermal winds were filtered out. Thigmomorphogenesis was therefore driven by intense storms. Thigmomorphogenesis is also likely to be involved in determining social status.
authors.affiliation: UMR 1092 LERFOB, INRA, Champenoux, 54280, France.|UMR 1092 LERFOB, AgroParisTech, Nancy, 54000, France.
authors.forename: Vivien
authors.identifier: http://orcid.org/0000-0002-2194-3652
authors.initials: V
authors.lastname: Bonnesoeur
authors.affiliation: UMR 1092 LERFOB, INRA, Champenoux, 54280, France.|UMR 1092 LERFOB, AgroParisTech, Nancy, 54000, France.
authors.forename: Thiéry
authors.initials: T
authors.lastname: Constant
authors.affiliation: UMR 547 PIAF, Clermont Université, Université Blaise Pascal, BP 10448, Clermont-Ferrand, 63000, France.|UMR 547 PIAF, INRA, Clermont-Ferrand, 63100, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Moulia
authors.affiliation: UMR 1092 LERFOB, INRA, Champenoux, 54280, France.|UMR 1092 LERFOB, AgroParisTech, Nancy, 54000, France.
authors.forename: Meriem
authors.initials: M
authors.lastname: Fournier
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D016001:Confidence Intervals; D065928:Forests; D008954:Models, Biological; D013314:Stress, Mechanical; D014197:Trees / Q000254:growth & development / Q000502:physiology*; D014919:Wind
keywords: Fagus sylvatica L. (European beech); forest; social status or crown class; strain sensing; thigmomorphogenesis; wind