Flexible foliar stoichiometry reduces the magnitude of the global land carbon sink | CU Experts

Increased plant growth under elevated CO2 slows the pace of climate; warming and underlies projections of terrestrial carbon (C) and climate; dynamics. 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 show that; incorporating CO2-driven foliar stoichiometry into the Community Land; Model reduced the projected land C sink two-fold by the end of the; century compared to simulations with fixed foliar chemistry. Further,; flexible foliar C:N profoundly altered Earth’s hydrologic cycle,; reducing evapotranspiration and increasing runoff. Belowground N cycling; rates were reduced in the flexible scenario, highlighting the urgency of; further research examining both the direct and indirect effects of; changing foliar stoichiometry on soil N cycling and plant productivity.

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