Researchers tested whether trees can actively detect their own curvature, rather than simply springing back or responding to gravity and light. They used an experimental setup that could suspend those external directional cues during movement in poplar stems (Populus tremula × alba).
Engineering & Technology2 weeks ago
Trees sense when they bend and grow wood to straighten themselves
Experiments with poplar stems show that sensing their own curvature helps trees form tension wood and recover a straight posture.
How poplar stems straighten
When curved poplar stems began to straighten, they formed tension wood on the convex side of the curve until the stems returned to straightness. By measuring stem movement and tension wood formation, the researchers identified a curvature-dependent control rule and estimated how sensitive the stems were to their own curvature. The findings show that tension wood formation is driven by the balance between gravity sensing and curvature sensing.
Why self-sensing matters
The study changes the usual explanation of tension wood, which is often viewed mainly as a response to gravity or other directional cues. It shows that active self-sensing helps trees counter-curvature and maintain their posture, providing evidence for a form of postural control in trees that does not depend only on external signals.
Evidence and limits
This is an experimental study using a novel setup to control phototropic and gravitropic sensing while tracking movement and tension wood formation in poplar stems. The results directly support active, curvature-driven straightening in the tested stems. The abstract does not give the sample size or establish whether the same control process operates in other tree species or under natural field conditions.
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New Phytologist · 2026 · DOI: 10.1111/nph.71238
Authors: Alexandre Caulus, Félix Hartmann, Éric Badel, Stéphane Ploquin, Nicole Brunel-Michac, Julien Ruelle, Mélanie Decourteix, Bruno Moulia
Institutions: Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Université de Lorraine, Clermont Université, University of Clermont Auvergne, AgroParisTech, Silva, Ecologie et Ecophysiologie Forestières
