Extended Data Fig. 1: Schematic description of the effect of elevated atmospheric CO2 (eCO2) on nitrifiers in upland soil systems.
From: Inhibition of autotrophic nitrifiers in a nitrogen-rich paddy soil by elevated CO2
CO2-enhancement of plant and microbial activities stimulates the growth of autotrophic nitrifiers by increasing soil CO2 (1) or inhibits their growth by reducing the supply of NH4+ when the system is N limited (2). Also, eCO2 often increases soil moisture through decreasing plant evapotranspiration, leading to either a stimulation effect on nitrifiers by alleviating water stress (3) or a suppression effect by reducing the diffusion of O2 into the soil (4). As such, the apparent eCO2 effect on nitrifiers likely depends on the overall response of nitrifiers to eCO2-induced changes of limiting factors or which of limiting factors will have an overarching effect on nitrifiers under eCO2. Arrows with ‘+’ and ‘-’ represent positive and negative effect, respectively.
