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

• 成果类型: Article
• 署名作者: Zhang, Han; Wang, Han; Wright, Ian J.; Prentice, I. Colin; Harrison, Sandy P.; Smith, Nicholas G.; Westerband, Andrea C.; Rowland, Lucy; Plavcova, Lenka; Morris, Hugh; Reich, Peter B.; Jansen, Steven; Keenan, Trevor; Nguyen, Ngoc Bao
• 署名单位: Tsinghua University; Western Sydney University; Macquarie University; Western Sydney University; Imperial College London; University of Reading; Texas Tech University System; Texas Tech University; University of Louisiana Lafayette; University of Exeter; Czech University of Life Sciences Prague; University of Michigan System; University of Michigan; University of Michigan System; University of Michigan; University of Minnesota System; University of Minnesota Twin Cities; Ulm University; University of California System; University of California Berkeley; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12993
• DOI: 10.1126/science.adr9978
• 发表日期: 2025-05-29
• 页码: 984-988
• 关键词: co2 efflux; secondary xylem; hydraulic conductance; heartwood formation; seasonal-variation; measurement error; water storage; black spruce; jack pine; forest

摘要

The efflux of carbon dioxide (CO2) 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 CO2 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.