Fig. 6: Results of generalized additive models (GAM) for population differentiation and clinal variation in single traits.

Illustrated are plot tree density (n living trees per plot), tree annual volume increment, tree annual wood density, and tree annual biomass increment. The number of sampled independent populations in the analysis was n = 42 for Mont-Laurier and n = 45 for Chibougamau, each having three replicates. All shown variables are significant at the two-sided 5% level. See Fig. 2 for definitions.