Tension wood occurrence in three cultivars of Populus × euramericana. Part I: Inter-clonal and intra-tree variability of tension wood Miguel Angel Badia, Thiéry Constant, Frédéric Mothe and Gérard NepveuAnn. For. Sci., 63 1 (2006) 23-30DOI: https://doi.org/10.1051/forest:2005095