Fig. 2

Linear regressions between the total native tree taxa richness and the surface of continental administrative areas (black regression line and black circles) or main islands (grey regression line and black triangles) in the Mediterranean-European region with their respective 95% confidence interval. Abscissa and ordinate axes have a logarithmic scale. Dots above each line indicate higher richness than predicted by the species-area relationship, and dots below each line indicate lower richness than expected