Inbreeding depression (% ID) due to selfing (black) and open pollination (grey) for survival (SURV), basal area per hectare (BAH) and stem diameter of surviving trees (DBH) at different ages from planting. The statistical significance of pairwise differences between the estimated least-squares means of the polymix crossing and the self or open-pollinated populations is indicated for each trait and age (see also Appendix¹ 1): ***, P ≤ 0.001; **, P ≤ 0.01; *, P ≤ 0.05; ns, P > 0.05.