Figure 3: Observed feedback at the individual level. (a) PopTrait ex situ experiment in Clermont-Ferrand for understandingP. nigra responses to biomechanical constraints; (b) sediment tail downstream of a multi-stemmed black poplar on an alluvial bar of the Tech River. The morphology of the sediment tail is correlated with morphological traits of the black poplar individual. Photographs: Virginia Garófano-Gómez (a) and Aurélien Chabanon (b).