Fig. 4

PCA results showing the factor coordinates of the variables and provenances (•) on the plane defined by the first two principal components (PC). The ellipses denote the different groups defined according to hierarchical ascendant classification (HAC) on the same variables. Variables are basal area (BA), earlywood density (EWD), growth index in 2003 (GI ₂₀₀₃) and growth index in 2004 (GI ₂₀₀₄). Supplementary climatic variables from the natural range are represented by a grey dashed line: mean annual temperature (MAT), mean annual precipitation (MAP) and annual heat moisture index (AHM). Boxed codes indicate IUFRO provenance codes, colours indicate different geographical origins: black for Californian and Oregon Coastal provenances, grey for south interior provenances, white and gray for northern provenances from British Columbia