The fate of carbon in a mature forest under carbon dioxide enrichment
The fate of carbon in a mature forest under carbon dioxide enrichment
Abstract Atmospheric carbon dioxide enrichment (eCO2) can enhance plant carbon uptake and growth1,2,3,4,5, thereby providing an important negative feedback to climate change by slowing the rate of increase of the atmospheric CO2 concentration6. While evidence gathered from young aggrading forests has generally indicated a strong CO2 fertilization effect on biomass growth3,4,5, it is unclear whether mature forests respond to eCO2 in a similar way. In mature trees and forest stands7,8,9,10, photosynthetic uptake has been found to increase under eCO2 without any apparent accompanying growth response, leaving an open question about the fate of additional carbon fixed under eCO24, 5, 7,8,9,10,11. Here, using data from the first ecosystem-scale Free-Air CO2 Enrichment (FACE) experiment in a mature forest, we constructed a comprehensive ecosystem carbon budget to track the fate of carbon as the forest responds to four years of eCO2 exposure. We show that, although the eCO2 treatment of ambient +150 ppm (+38%) induced a 12% (+247 gCm-2yr-1) increase in carbon uptake through gross primary production, this additional carbon uptake did not lead to increased carbon sequestration at the ecosystem level. Instead, the majority of the extra carbon was emitted back into the atmosphere via several respiratory fluxes, with increased soil respiration alone contributing ～50% of the total uptake surplus. Our results call into question the predominant thinking that the capacity of forests to act as carbon sinks will be generally enhanced under eCO2, and challenge the efficacy of climate mitigation strategies that rely on CO2 fertilization as a driver of increased carbon sinks in standing forests and afforestation projects.
Medlyn B.E.、Ellsworth D.S.、Drake J.E.、Boer M.M.、Crous K.Y.、De Kauwe M.G.、Facey S.L.、Gimeno T.E.、Johnson S.N.、Mahmud K.、Moore B.D.、Ochoa-Hueso R.、Powell J.R.、Power S.A.、Reich P.B.、Riegler M.、Tjoelker M.G.、Barton C.V.M.、Zaehle S.、Casta?eda-G¨?mez L.、Wujeska-Klause A.、Noh N.J.、Yang J.、Duursma R.A.、Emmerson K.M.、Jiang M.、Nazaries L.、Anderson I.C.、Hasegawa S.、Pendall E.、Salom¨?n R.L.、Nielsen U.N.、Walker J.K.M.、Rymer P.、Pathare V.S.、Collins L.、Pineiro J.、Smith B.、Singh B.K.、Carrillo Y.、Gherlenda A.N.、Macdonald C.A.、Renchon A.A.
Hawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney University||Department of Forest and Natural Resources Management, College of Environmental Science and Forestry, State University of New YorkHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityARC Centre of Excellence for Climate Extremes, University of New South WalesHawkesbury Institute for the Environment, Western Sydney University||Department of Ecology, Swedish University of Agricultural Sciences (SLU)Hawkesbury Institute for the Environment, Western Sydney University||Basque Centre for Climate Change||Ikerbasque, Basque Foundation for ScienceHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney University||Department of Biology, IVAGRO, University of C¨￠diz, Campus de Excelencia Internacional Agroalimentario (CeiA3)Hawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney University||Department of Forest Resources, University of MinnesotaHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityMax Planck Institute for BiogeochemistryHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityClimate Science Centre, CSIRO Oceans & Atmosphere, AspendaleHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney University||Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Ume?Hawkesbury Institute for the Environment, Western Sydney UniversityLaboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney University||School of Biological Sciences, Post Office Box 646340, Washington State UniversityHawkesbury Institute for the Environment, Western Sydney University||Department of Ecology, Environment and Evolution, La Trobe University||Arthur Rylah Institute for Environmental Research, Department of Environment, Land, Water and PlanningHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney University||Department of Physical Geography and Ecosystem Science, Lund UniversityHawkesbury Institute for the Environment, Western Sydney University||Global Centre for Land Based Innovation, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney UniversityHawkesbury Institute for the Environment, Western Sydney University
环境科学理论环境科学技术现状环境生物学
Medlyn B.E.,Ellsworth D.S.,Drake J.E.,Boer M.M.,Crous K.Y.,De Kauwe M.G.,Facey S.L.,Gimeno T.E.,Johnson S.N.,Mahmud K.,Moore B.D.,Ochoa-Hueso R.,Powell J.R.,Power S.A.,Reich P.B.,Riegler M.,Tjoelker M.G.,Barton C.V.M.,Zaehle S.,Casta?eda-G¨?mez L.,Wujeska-Klause A.,Noh N.J.,Yang J.,Duursma R.A.,Emmerson K.M.,Jiang M.,Nazaries L.,Anderson I.C.,Hasegawa S.,Pendall E.,Salom¨?n R.L.,Nielsen U.N.,Walker J.K.M.,Rymer P.,Pathare V.S.,Collins L.,Pineiro J.,Smith B.,Singh B.K.,Carrillo Y.,Gherlenda A.N.,Macdonald C.A.,Renchon A.A..The fate of carbon in a mature forest under carbon dioxide enrichment[EB/OL].(2025-03-28)[2025-05-01].https://www.biorxiv.org/content/10.1101/696898.点此复制
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