Variations of some key abundance ratios across the log T_eff–log g plane. For the NLTE lithium abundances, the downward-pointing triangles denote upper limits. The predictions at solar metallicity of evolutionary models for masses of 1.5, 3, and 4 M_⊙ are overplotted for illustrative purposes. Same tracks as in Fig. 1, except that the evolutionary phase, is not colour coded.