Plot ordination based on the two first axes resulting from a Principal Component Analysis on canopy structural variables. The projections of sampling stands (C, calcareous; S, serpentines) on the PC1 match up with the initial arrangement of their stand successional stage (1, early agradative; 2, stem exclusion; 3 to 5, old-growth) based on historical management data and observational field surveys. PC2 is related to the degree of canopy closure. Eigenvalues and loading factors are listed in Table III.