Flexible foliar stoichiometry reduces the magnitude of the global land carbon sink

However, this important ecosystem service may be diminished by concurrent changes to vegetation carbon-to-nitrogen (C:N) ratios. Despite clear observational evidence of increasing foliar C:N under elevated CO2, our understanding of potential ecological consequences of foliar stoichiometric flexibility is incomplete.

Here, we illustrate that when we incorporated CO2-driven increases in foliar stoichiometry into the Community Land Model the projected land C sink decreased two-fold by the end of the century compared to simulations with fixed foliar chemistry. Further, CO2-driven increases in foliar C:N profoundly altered Earth's hydrologic cycle, reducing evapotranspiration and increasing runoff, and reduced belowground N cycling rates.