Trait relationships across light, water and nutrient regimes between total biomass accumulated versus Amax(a), WUE (b), SLA (c), number of tubers (d), chlorophyll content (e) and leaf N concentration (f). The LP form is represented by triangles (▲) and a solid line (―) while the SP form is represented by open circles (○) and dotted lines (---). Significant relations (P<0.05) are shown by underlined R2 values, **, P < 0.0001; *, P < 0.05.