Fraction of baryons in stars (f_*) plotted against the total fraction of baryons (f_b) for all substructures identified by SUBFIND in the stellar mass range of 10⁴ ≤ M_*[M_⊙]≤10⁸ at z = 6. The sizes of the symbols indicate the mass range of the substructures. The vertical line represents the WMAP 7-year universal baryon fraction value of 0.167 (Komatsu et al. 2011). From top to bottom the colour bars represent: the stellar metallicity of the substructures, the stellar mass of the parent friend-of-friends (FOF) halo, and the dark matter mass of the parent FOF haloes.