Specific leaf area was not affected either by site or seed source (Table 2; Supplementary Data Fig. S2). In addition, it was not related to the climate of the plantation sites (MJT) (P ≥ 0.10). Needle nitrogen concentration (Nmass) was similar among seed sources but was affected by sites (Table 2). Similar results were obtained using needle nitrogen content per unit of needle projected area. Mean Nmass was greater in the Asselin, Deville and Picard sites than in the Lac Bergeron, Wendover and Dorion sites (Supplementary Data Fig. S2). Both Rd10 and Aopt were unrelated to leaf nitrogen (Nmass) (Supplementary Data Fig. S3).