Relationship between plant community, N concentration, and carbon fluxes
Removal of foliar fungi or soil fungi reduced the relative abundance of C4 grasses and increased leguminous forbs (Table S8, Fig. S2). Mass specific fluxes (GPP and Re) declined with increasing abundance of C4 plants and increasing belowground biomass (Table S9, Fig. 4), and increased with community-wide foliar N content (Table S10, Fig. 5) as would be expected from a shift towards a more resource conservative plant strategy. These trends were interrelated: community foliar N content increased as the relative abundance of leguminous forbs increased, and decreased with an increase in C4 grasses and in belowground biomass (p<0.001, Table S11, Fig. 6). Removal of heterotrophs weakened the relationship between mass-specific fluxes and foliar N content (Table S10) and between foliar N content and belowground biomass (Table S11).