Decoupled carbon assimilation and growth responses to aridity in temperate deciduous oaks
北米の温帯落葉樹オークにおける乾燥に対する炭素同化と成長の非同期応答 (AI 翻訳)
Mukund Palat Rao, Arturo Pacheco-Solana, Rong Li, Bar Oryan, Johanna Jensen, Milagros Rodríguez‐Catón, Lily Klinek, Zoe Pierrat, Sophie Ruehr, Rose Oelkers, Laura E. Boeschoten, Kevin L. Griffin, Michael McCormack, Xi Yang, Joseph Verfaillie, Dennis Baldocchi, Jeremy Hise, Alexander J. Turner, Todd M. Scanlon, Laia Andreu‐Hayles +9
🤖 gxceed AI 要約
日本語
本研究は、北米の8種のオークにおいて光合成と地上部成長が日～季節スケールで非同期であることを示した。年輪データから、現在年の成長は盛夏以降の気候変動に影響を受けず、年間総一次生産の26～36%がこの期間に起こることが明らかになった。時間分解能の高いデータから、木部形成は光合成よりも早期に停止し、低大気乾燥・低温時に限定されることが確認された。この非同期性は蒸気圧欠損の年々変動と強く相関し、現在の地球システムモデルが森林の長期的炭素隔離を過大評価している可能性を示唆する。
English
This study demonstrates that photosynthesis and aboveground growth are asynchronous across diel to seasonal scales in eight North American oak species. Using tree-ring and flux data, they show that current-year growth is insensitive to climate after midsummer, despite significant GPP during that period, and wood formation ceases earlier than photosynthesis, restricted to periods of low aridity and temperature. This decoupling, correlated with vapor pressure deficit variability, suggests Earth system models may overestimate long-term carbon sequestration in forests.
Unofficial AI-generated summary based on the public title and abstract. Not an official translation.
📝 gxceed 編集解説 — Why this matters
日本のGX文脈において
我が国は2050年ネットゼロ目標の達成に森林炭素吸収源を重要な柱と位置付けている。本論文は、気候変動下での森林の炭素固定能について、現在の気候モデル（地球システムモデル）が過大評価する可能性を実験的に示しており、日本の炭素収支予測や森林管理政策の再検討を促す実証的根拠となる。
In the global GX context
This paper provides critical empirical evidence that the tight coupling between photosynthesis and woody biomass assumed in Earth system models may be flawed, especially under increasing aridity. This has direct implications for global carbon cycle projections, IPCC assessments, and the credibility of nature-based carbon offsets, which are key elements in global climate disclosure and transition finance frameworks.
👥 読者別の含意
🔬研究者:Highlights the need to revise carbon allocation schemes in Earth system models to account for photosynthesis-growth decoupling under water stress.
🏢実務担当者:For forest carbon project developers, this suggests that carbon sequestration estimates based solely on GPP may overstate actual woody biomass accumulation.
🏛政策担当者:Provides evidence that forest carbon sink projections in national inventories and climate pledges may be overoptimistic, warranting more conservative accounting.
📄 Abstract（原文）
The magnitude of the terrestrial carbon sink remains a key uncertainty in future climate projections, in part due to poorly understood links between carbon uptake and its allocation to woody biomass in vegetation. Here, in this study, we show that photosynthesis and aboveground growth occur asynchronously across diel to seasonal scales in eight North American oak species. Across 137 tree ring sites, current-year annual growth was insensitive to climate variability after midsummer despite 26 to 36% of annual gross primary productivity (GPP) occurring during this period. Hourly GPP flux and growth measurements at four sites spanning seven site years further demonstrate that wood formation ceases earlier than photosynthesis and is restricted to periods of low atmospheric aridity and temperature. This photosynthesis-growth decoupling intensifies with interannual variability in vapor pressure deficit ( r = 0.86, P < 0.05), suggesting that by assuming tight coupling between photosynthesis and woody biomass, current earth system models may overestimate long-term carbon sequestration in forests.
🔗 Provenance — このレコードを発見したソース
- openalex https://doi.org/10.1126/sciadv.ady7139first seen 2026-06-26 05:07:23
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