Fig. 4
From: Tree growth is more limited by drought in rear-edge forests most of the times
Correlations (Pearson coefficients) calculated between mean site series of ring-width indices and precipitation (left) and temperature (right) deviations. Dots indicate significant coefficients according to bootstrapping tests. Colours represent: northern (blue), intermediate (black), and southern (brown) populations of the six tree species (a, Pinus uncinata; b, Abies alba; c, Fagus sylvatica; d, Pinus sylvestris; e, Quercus robur; f, Quercus petraea)