Thermal acclimation of stem respiration implies a weaker carbon-climate feedback

Zhang, H. ORCID: https://orcid.org/0009-0008-9231-2939, Wang, H. ORCID: https://orcid.org/0000-0003-2482-1818, Wright, I. J. ORCID: https://orcid.org/0000-0001-8338-9143, Prentice, I. C. ORCID: https://orcid.org/0000-0002-1296-6764, Harrison, S. P. ORCID: https://orcid.org/0000-0001-5687-1903, Smith, N. G. ORCID: https://orcid.org/0000-0001-7048-4387, Westerband, A. C. ORCID: https://orcid.org/0000-0003-4065-9689, Rowland, L. ORCID: https://orcid.org/0000-0002-0774-3216, Plavcová, L. ORCID: https://orcid.org/0000-0002-3395-4463, Morris, H. ORCID: https://orcid.org/0000-0002-7548-0796, Reich, P. B. ORCID: https://orcid.org/0000-0003-4424-662X, Jansen, S. ORCID: https://orcid.org/0000-0002-4476-5334, Keenan, T. ORCID: https://orcid.org/0000-0002-3347-0258 and Nguyen, N. B. ORCID: https://orcid.org/0000-0002-4634-8390 (2025) Thermal acclimation of stem respiration implies a weaker carbon-climate feedback. Science, 388 (6750). pp. 984-988. ISSN 1095-9203 doi: 10.1126/science.adr9978

Abstract/Summary

The efflux of carbon dioxide (CO 2 ) from woody stems, a proxy for stem respiration, is a critical carbon flux from ecosystems to the atmosphere, which increases with temperature on short timescales. However, plants acclimate their respiratory response to temperature on longer timescales, potentially weakening the carbon-climate feedback. The magnitude of this acclimation is uncertain despite its importance for predicting future climate change. We develop an optimality-based theory dynamically linking stem respiration with leaf water supply to predict its thermal acclimation. We show that the theory accurately reproduces observations of spatial and seasonal change. We estimate the global value for current annual stem CO 2 efflux as 27.4 ± 5.9 PgC. By 2100, incorporating thermal acclimation reduces projected stem respiration without considering acclimation by 24 to 46%, thus reducing land ecosystem carbon emissions.

Item Type	Article
URI	https://centaur.reading.ac.uk/id/eprint/123139
Identification Number/DOI	10.1126/science.adr9978
Refereed	Yes
Divisions	Science > School of Archaeology, Geography and Environmental Science > Department of Geography and Environmental Science
Publisher	American Association for the Advancement of Science (AAAS)
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