Nitrogen and phosphorus constrain the CO2 fertilization of global plant biomass

• Published in: Nature climate change Vol. 9; no. 9; pp. 684 - 689
• Main Authors: Terrer, César, Jackson, Robert B., Prentice, I. Colin, Keenan, Trevor F., Kaiser, Christina, Vicca, Sara, Fisher, Joshua B., Reich, Peter B., Stocker, Benjamin D., Hungate, Bruce A., Peñuelas, Josep, McCallum, Ian, Soudzilovskaia, Nadejda A., Cernusak, Lucas A., Talhelm, Alan F., Van Sundert, Kevin, Piao, Shilong, Newton, Paul C. D., Hovenden, Mark J., Blumenthal, Dana M., Liu, Yi Y., Müller, Christoph, Winter, Klaus, Field, Christopher B., Viechtbauer, Wolfgang, Van Lissa, Caspar J., Hoosbeek, Marcel R., Watanabe, Makoto, Koike, Takayoshi, Leshyk, Victor O., Polley, H. Wayne, Franklin, Oskar
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2019; Nature Publishing Group
• Subjects: 631/158/2165; 704/106/47; 704/106/694/2786; 704/158/2445; Biological fertilization; Biomass; Boreal ecosystems; Carbon capture and storage; Carbon dioxide; Carbon sequestration; Climate Change; Climate Change/Climate Change Impacts; Earth and Environmental Science; Environment; Environmental Law/Policy/Ecojustice; ENVIRONMENTAL SCIENCES; Experiments; Fertilization; Global warming; Letter; Mineral nutrients; Nitrogen; Nutrient availability; Nutrients; Phosphorus; Plant biomass; Plant growth; Soil; Soil nutrients; Vegetation
• ISSN: 1758-678X; 1758-6798
• DOI: 10.1038/s41558-019-0545-2

Elevated CO 2 (eCO 2 ) experiments provide critical information to quantify the effects of rising CO 2 on vegetation 1 – 6 . Many eCO 2 experiments suggest that nutrient limitations modulate the local magnitude of the eCO 2 effect on plant biomass 1 , 3 , 5 , but the global extent of these limitations has not been empirically quantified, complicating projections of the capacity of plants to take up CO 2 7 , 8 . Here, we present a data-driven global quantification of the eCO 2 effect on biomass based on 138 eCO 2 experiments. The strength of CO 2 fertilization is primarily driven by nitrogen (N) in ~65% of global vegetation and by phosphorus (P) in ~25% of global vegetation, with N- or P-limitation modulated by mycorrhizal association. Our approach suggests that CO 2 levels expected by 2100 can potentially enhance plant biomass by 12 ± 3% above current values, equivalent to 59 ± 13 PgC. The future effect of eCO 2 we derive from experiments is geographically consistent with past changes in greenness 9 , but is considerably lower than the past effect derived from models 10 . If borne out, our results suggest that the stimulatory effect of CO 2 on carbon storage could slow considerably this century. Our research provides an empirical estimate of the biomass sensitivity to eCO 2 that may help to constrain climate projections. Elevated CO 2 increases plant biomass, providing a negative feedback on global warming. Nutrient availability was found to drive the magnitude of this effect for the majority of vegetation globally, and analyses indicated that CO 2 will continue to fertilize plant growth in the next century.