Reply to: The size of tropical vegetation gross primary production

A study published in Nature on June 3, 2026, addresses the scale of gross primary production (GPP) in tropical vegetation. The research refutes previous estimates that suggested tropical GPP was significantly underestimated, particularly concerning the role of savannas. The authors, citing data from the FLUXNET network, argue that current models accurately capture the GPP of tropical forests, which account for approximately 40% of global terrestrial GPP. They highlight that while savannas contribute substantially to tropical GPP, their inclusion in global estimates is already standard practice. The study emphasizes that the observed GPP in tropical forests is consistent with established physiological limits and ecosystem dynamics, suggesting no widespread underestimation. This clarification is crucial for climate modeling and understanding the global carbon cycle, as it reinforces the current understanding of tropical ecosystems' role in carbon sequestration. The research team utilized a combination of eddy covariance flux data and satellite-derived vegetation indices to validate their findings. Their analysis indicates that the total tropical GPP is around 100 petagrams of carbon per year, a figure that aligns with widely accepted scientific consensus. The paper aims to correct a potential misinterpretation of earlier findings that had suggested a much larger, uncaptured GPP in tropical regions.