Fig. 1. Shoot N per unit dry mass (N_SM) in relation to shoot dry mass (M_S) of individuals. Lines denote N*_SM during a 5‐week regrowth period for Medicago sativa: plants grown with high PFD/high N supply (I+N+, solid line, N*_SMN+ = 34·8 M_S^–0·196, r² = 0·73, n = 24) or high PFD/low N supply (I+N–, dashed line, N*_SMN‐ = 19·9 M_S^–0·285, r² = 0·73, n = 24). Symbols denote N_SM (mean ± s.e.) of individuals after 5 weeks regrowth. A, M. sativa grown with high PFD and high N supply (I+N+, filled circles), high PFD and low N supply (I+N–, filled upright triangles), low PFD and high N supply (I–N+, filled inverted triangles), low PFD and low N supply (I–N–, filled diamonds), in conditions changing from high to low PFD and N supply (cI–N–, filled squares) (expt 3, n = 12), grown in dense (open circles) and open (open upright triangles) monocultures and in Lolium multiflorum (open inverted triangles) and Poa pratensis (open diamonds) stands (n = 6). B, Dactylis glomerata (filled symbols) and Taraxacum officinale (open symbols) grown in dense (circles) and open (upright triangles) monocultures and in L. multiflorum (inverted triangles), Lolium perenne (open squares) and P. pratensis (diamonds) stands (n = 6).