Effects of plant diversity and heterotroph removal on mass-specific C fluxes
After accounting for the positive effects of plant diversity and removal of foliar fungi on plant biomass (Seabloom et al. 2017; Fig. S1, Table S1), we found that there was no main effect of plant diversity on mass-specific C fluxes. Simultaneous removal of all heterotrophs and independent removal of arthropods or soil fungi did not affect mass-specific fluxes. However, independent removal of foliar fungi increased both mass-specific GPP and Re with an overall increase in mass-specific NEE, i.e., a greater net carbon uptake per unit plant mass (Tables S5-S7, Fig. 3). The effect of foliar fungi on mass-specific fluxes was greatest at low plant diversity.