Open AccessCO 2 fertilization of terrestrial photosynthesis inferred from site to global scales
Author(s) -
Chi Chen,
William J. Riley,
Iain Colin Prentice,
Trevor F. Keenan
Publication year - 2022
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2115627119
Subject(s) - photosynthesis , human fertilization , c4 photosynthesis , environmental science , ecosystem , atmospheric sciences , biology , ecology , agronomy , botany , geology
Significance The magnitude of the CO2 fertilization effect on terrestrial photosynthesis is uncertain because it is not directly observed and is subject to confounding effects of climatic variability. We apply three well-established eco-evolutionary optimality theories of gas exchange and photosynthesis, constraining the main processes of CO2 fertilization using measurable variables. Using this framework, we provide robust observationally inferred evidence that a strong CO2 fertilization effect is detectable in globally distributed eddy covariance networks. Applying our method to upscale photosynthesis globally, we find that the magnitude of the CO2 fertilization effect is comparable to its in situ counterpart but highlight the potential for substantial underestimation of this effect in tropical forests for many reflectance-based satellite photosynthesis products.