Researchers found that trees use proprioception—an internal sense of their shape and position—to regulate growth and correct their posture.

To test this ability without gravity or directional light cues, researchers placed young poplars horizontally on a rotating platform inside a sphere illuminated evenly from every direction.

The stems first curved upward as tension wood formed along their upper sides, pulling them toward vertical; once in the apparatus, the trees gradually straightened over the following weeks.

The findings show tension wood can form on either side of a stem, with trees coordinating its development through a sensorimotor process that links awareness of posture to physical growth.

As the trees straightened, tension wood stopped forming on the original side and developed on the opposite side, creating an opposing pull that helped restore a straight shape.

Bruno Moulia said poorly coordinated tension-wood formation can create internal stresses that affect wood quality, while Félix Hartman highlighted the interdisciplinary collaboration behind the research.

The mechanism may help trees recover from storms, landslides and other disturbances, and could inform efforts to select straighter-growing trees, reduce crop lodging and improve timber quality.