Global Change Biology最新文献

{"title":"Activation Energy of Organic Matter Decomposition in Soil and Consequences of Global Warming","authors":"Ekaterina Filimonenko,&nbsp;Yakov Kuzyakov","doi":"10.1111/gcb.70472","DOIUrl":"https://doi.org/10.1111/gcb.70472","url":null,"abstract":"<p>The activation energy (<i>E</i>_<i>a</i>) is the minimum energy necessary for (bio)chemical reactions acting as an energy barrier and defining reaction rates, for example, organic matter transformations in soil. Based on the <i>E</i>_<i>a</i> database of (i) oxidative and hydrolytic enzyme activities, (ii) organic matter mineralization and CO₂ production, (iii) heat release during soil incubation, as well as (iv) thermal oxidation of soil organic matter (SOM), we assess the <i>E</i>_<i>a</i> of SOM transformation processes. After a short description of the four approaches to assess these <i>E</i>_<i>a</i> values—all based on the Arrhenius equation—we present the <i>E</i>_<i>a</i> of chemical oxidation (79 kJ mol⁻¹, based on thermal oxidation), microbial mineralization (67 kJ mol⁻¹, CO₂ production), microbial decomposition (40 kJ mol⁻¹, heat release), and enzyme-catalyzed hydrolysis of polymers and cleavage of mineral ions of nutrients (33 kJ mol⁻¹, enzyme driven reactions) from SOM. The catalyzing effects of hydrolytic and oxidative enzymes reduce <i>E</i>_<i>a</i> of SOM decomposition by more than twice that of its chemical oxidation. The <i>E</i>_<i>a</i> of enzymatic cleavage of mineral ions of N, P, and S from their organic compounds is 9 kJ mol⁻¹ lower (corresponding to 40-fold faster reactions) than the hydrolysis of N-, P-, and S-free organic polymers. In soil, where organic compounds are physically protected and enzymes are partly deactivated, microbial mineralization is ~140-fold faster compared to its pure chemical oxidation. Because processes with higher <i>E</i>_<i>a</i> are more sensitive to temperature increase, global warming will accelerate the decomposition of stable organic compounds and boost the C cycle much stronger than the cycling of nutrients: N, P, and S. Consequently, the stoichiometry of microbially utilized compounds in warmer conditions will shift toward organic pools with higher C/N ratios. This will decouple the cycling of C and nutrients: N, P, and S. Overall, the <i>E</i>_<i>a</i> of (bio)chemical transformations of organic matter in soil enables to assess process rates and the inherent stability of SOM pools, as well as their responses to global warming.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70472","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144935105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Local Adaptation Drives Leaf Thermoregulation in Tropical Rainforest Trees","authors":"Kali B. Middleby,&nbsp;Rebecca Jordan,&nbsp;Alexander W. Cheesman,&nbsp;Maurizio Rossetto,&nbsp;Martin F. Breed,&nbsp;Darren M. Crayn,&nbsp;Lucas A. Cernusak","doi":"10.1111/gcb.70461","DOIUrl":"https://doi.org/10.1111/gcb.70461","url":null,"abstract":"<p>Tropical forests play a critical role in biodiversity, carbon sequestration, and climate regulation, but are increasingly affected by heatwaves and droughts. Vulnerability to warming may vary within and between species because of phenotypic divergence. Leaf trait variation can affect leaf operating temperatures—a phenomenon termed ‘limited homeothermy’ when it helps avoid heat damage in warmer conditions. However, evidence for this capacity and the relative roles of acclimation or adaptation remain limited. We measured photosynthetic heat tolerance and leaf thermal traits of three co-occurring rainforest tree species across a thermal gradient in the Australian Wet Tropics. Using a leaf energy balance model parameterised with field-measured traits, we predicted variation in leaf-to-air temperature differences (∆<i>T</i>_trait) and resulting thermal safety margins. We combined this with individual-based genome-wide data to detect signals of adaptive divergence and validated findings in a glasshouse trial with provenances grown under contrasting temperature and humidity conditions. Intraspecific trait variation reduced ∆<i>T</i>_trait and increased heat tolerance in warmer sites for <i>Darlingia darlingiana</i> and <i>Elaeocarpus grandis,</i> but not <i>Cardwellia sublimis</i>. As a result, thermal safety margins declined less steeply with increasing growth temperature in species capable of increased heat tolerance and avoidance, indicating these strategies can effectively buffer warming. All species showed genomic signals of selection, with associations to temperature and moisture variables. In <i>E. grandis</i>, glasshouse results confirmed a negative cline in ∆<i>T</i>_trait with temperature of origin. Although contrasting growth temperature and humidity lead to acclimation of individual traits, their coordination maintained ∆<i>T</i>_trait across the conditions imposed. Our findings provide evidence of limited homeothermy and suggest climate gradients have selected for trait combinations that reduce leaf temperatures at warmer sites in some but not all species. Given the rapid pace of climate change, those species with limited capacity to adjust their thermal safety margins through acclimation or adaptation may be at greater risk of local extinction.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70461","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Greatest Extinction Event in 66 Million Years? Contextualising Anthropogenic Extinctions","authors":"Jack H. Hatfield,&nbsp;Bethany J. Allen,&nbsp;Tadhg Carroll,&nbsp;Christopher D. Dean,&nbsp;Shuyu Deng,&nbsp;Jonathan D. Gordon,&nbsp;Thomas Guillerme,&nbsp;James P. Hansford,&nbsp;Jennifer F. Hoyal Cuthill,&nbsp;Philip D. Mannion,&nbsp;Inês S. Martins,&nbsp;Alexander R. D. Payne,&nbsp;Amy Shipley,&nbsp;Chris D. Thomas,&nbsp;Jamie B. Thompson,&nbsp;Lydia Woods,&nbsp;Katie E. Davis","doi":"10.1111/gcb.70476","DOIUrl":"https://doi.org/10.1111/gcb.70476","url":null,"abstract":"<div>\u0000 \u0000 <p>Biological communities are changing rapidly in response to human activities, with the high rate of vertebrate species extinction leading many to propose that we are in the midst of a sixth mass extinction event. Five past mass extinction events have commonly been identified across the Phanerozoic, with the last occurring at the end of the Cretaceous, 66 million years ago (Ma). However, life on Earth has always changed and evolved, with most species ever to have existed now extinct. The question is, are human activities increasing the rate and magnitude of extinction to levels rarely seen in the history of life? Drawing on the literature on extinctions primarily over the last 66 million years (i.e., the Cenozoic), we ask: (1) what comparisons can meaningfully be drawn? and (2) when did the Earth last witness an extinction event on this scale? We conclude that, although challenging to address, the available evidence suggests that the ongoing extinction episode still falls a long way short of the devastation caused by the bolide impact 66 Ma, but that it has likely surpassed most other Cenozoic events in magnitude, with the possible exception of the Eocene–Oligocene transition (34 Ma), about which much uncertainty remains. Given the number of endangered and at-risk species, the eventual magnitude of the current event will depend heavily on humanity's response and how we interact with the rest of the biosphere over the coming millennia.</p>\u0000 </div>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ecosystem Phenology: Integrating Traits and Processes Beyond Observable Events","authors":"Lei Chen,&nbsp;Josep Peñuelas","doi":"10.1111/gcb.70480","DOIUrl":"https://doi.org/10.1111/gcb.70480","url":null,"abstract":"<p>Phenology—the study of seasonal biological events shaped by climate variability—has long offered critical insights into the impact of climate change on ecosystems. Traditionally, phenological research has focused on discrete and observable events such as budburst, leaf-out, flowering, and migration. Yet ecosystems are not driven by isolated events alone, but by continuous shifts in functional traits and biogeochemical processes. The event-based phenology framework often overlooks this dynamic variability in traits and processes. To completely understand the temporal change in ecosystem functioning, we propose an expanded concept—ecosystem phenology—which integrates functional traits and biochemical processes beyond visible events. By capturing the full temporal spectrum of ecosystem dynamics, the ecosystem phenology framework provides a comprehensive understanding of ecosystem responses to climate change, with significant implications for forecasting ecosystem function and informing climate policy.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70480","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144935103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding Unanticipated Range Shifts: Biotic Interactions as Key Mediators in a Changing Climate","authors":"Muyang Wang,&nbsp;Yingying Zhuo,&nbsp;Alice C. Hughes,&nbsp;Weikang Yang","doi":"10.1111/gcb.70470","DOIUrl":"https://doi.org/10.1111/gcb.70470","url":null,"abstract":"<p>Climate change poses one of the greatest threats to species survival in the 21st century. However, predicting species responses, identifying the most vulnerable species and locations, and determining effective conservation interventions remain significant challenges. Many studies employ correlative approaches to understand how species climate niches might be expected to shift under a changing climate by “tracking climate” and maintaining their climate niche. Species distribution models (SDMs) remain the primary tool for anticipating responses to climate change, yet most models are built on a straightforward correlation between current distribution points and prevailing environmental conditions. However, it is increasingly evident that a more nuanced, ecologically based approach is necessary (Lucas et al. <span>2025</span>). In newly published research in <i>Global Change Biology</i>, Osmolovsky et al. (<span>2025</span>) investigate the longstanding proposition that species will move upslope or away from the equator under climate change, or rather, when and why this is not always the case. However, mounting evidence shows that this is frequently not the case, with over a third of species examined (20%–37%) showing “counterintuitive” responses (Rubenstein et al. <span>2023</span>). This challenges the longstanding view of the need to track climatic niches and undermines the ability of models to perform accurately. Understanding why this might occur is clearly crucial for grasping the impacts of climate change, including where and why this might occur, especially given differing responses across species, even within a single locality (Gibson-Reinemer and Rahel <span>2015</span>). Importantly, understanding that these responses are not merely “an exception” is crucial, not only because they represent a large proportion of all known responses, but because the mechanistic elements provide insights into how and why species respond differently.</p><p>Osmolovsky et al. highlight the potential role of biotic interactions as a mediating factor to explain these unanticipated shifts, proposing the ‘Interaction Opportunists Hypothesis’. This hypothesis highlights that counterintuitive shifts to climate change may reflect changes in biotic interactions at the warmer edge of species' distributions. Further, these changing interactions may manifest through a number of different mechanisms. Principally the study explores three forms of interaction: reduced antagonistic interactions, increased positive interactions, and changes in equilibrium due to shifts in competitive dynamics between species. Ultimately these changes would either increase the suitability of previously marginal habitats on the warmer edge of the range (i.e., increasing the abundance of key resources) or reduce pressures that previously prevented species from occupying these spaces (such as predation pressure).</p><p>The “stress trade-off hypothesis”, anticipates that the cooler edge of speci","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70470","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144935104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Global Decarbonisation Potential of Synthetic Biology","authors":"Anthony Wiskich,&nbsp;Robert Speight","doi":"10.1111/gcb.70478","DOIUrl":"https://doi.org/10.1111/gcb.70478","url":null,"abstract":"<p>Synthetic biology-based technologies can impact many sectors and are often targeted at improved environmental outcomes. Here, we discuss synthetic biology applications that can lead to long-term decarbonisation and quantify the potential using a top-down approach. We find that promoting the restoration of agricultural land to natural ecosystems has the most potential. Boosting food production by raising agricultural productivity or producing alternative foods promotes this restoration by reducing agricultural land requirements. The carbon stocks in agricultural soil can also be increased. Reducing emissions in agriculture, industry and transport represents the second largest potential. Geoengineering-based mitigation and sequestration in nature is third. We outline what scale may be required for some technologies to achieve one gigaton (GtCe) of decarbonisation. We also highlight differences in the sensitivities of these technologies to carbon prices, agricultural land prices and greater circularity in economic processes. We hope that our high-level view of the decarbonisation potential of different synthetic biology application areas helps identify priorities and promotes the long-term contribution of these technologies towards climate change mitigation.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70478","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144935102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil Carbon Dynamics Reshaped by Ancient Carbon Quantification","authors":"Yoann Copard,&nbsp;Christine Hatté,&nbsp;Lauric Cécillon,&nbsp;Yannick Colin,&nbsp;Pierre Barré,&nbsp;Claire Chenu,&nbsp;Sophie Cornu","doi":"10.1111/gcb.70482","DOIUrl":"https://doi.org/10.1111/gcb.70482","url":null,"abstract":"<p>Soil is a major terrestrial carbon reservoir, and enhancing its carbon stock is a central strategy to mitigate climate change. Earth system models project a net soil carbon sink by 2100, the magnitude of which is still under debate, differing significantly between approaches. Radiocarbon-based studies often suggest a limited soil carbon accumulation capacity, but these estimates are biased by the presence of ancient, radiocarbon-free, organic carbon (aOC). This carbon no longer contributes to soil carbon dynamics and increases the average ¹⁴C age of soil carbon because it is radiocarbon-depleted. This known radiocarbon caveat can be overcome with a better understanding of the aOC (ancient radiocarbon-free OC) distribution in the world's soils. Here we apply a mixing linear equation to 313 soils worldwide from radiocarbon databases to estimate the aOC contained in soils. The aOC contained in soils has different origins, from rock-derived to old biospheric C strongly associated with mineral particles during pedogenesis. Our findings show a mean aOC content of 2.4 mg/g ±3.2 SD with an aOC contribution up to 11% of the soil organic carbon in topsoils (0–30 cm depth), reaching 25% in subsoils (30–100 cm depth) and more than half in deep soil (&gt; 100 cm depth). We demonstrate that the aOC content is particularly high in Andosols and Cryosols. We subtracted the aOC contributions to calculate a global mean corrected age of non-aOC carbon to 1 m depth of 290 years, contrasting sharply with previously reported values of 3100 to 4830 years. This corrected estimate aligns more closely with independent isotopic proxies (¹³C and ³⁶Cl) of soil carbon dynamics. These results also reconcile empirical data with the parameterization of Earth system models.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70482","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Projecting Uncertainty in Ecosystem Persistence Under Climate Change","authors":"Christina A. Buelow,&nbsp;Dominic A. Andradi-Brown,&nbsp;Thomas A. Worthington,&nbsp;Maria F. Adame,&nbsp;Rod M. Connolly,&nbsp;Catherine E. Lovelock,&nbsp;Kerrylee Rogers,&nbsp;Jaramar Villarreal-Rosas,&nbsp;Christopher J. Brown","doi":"10.1111/gcb.70468","DOIUrl":"https://doi.org/10.1111/gcb.70468","url":null,"abstract":"<p>Global projections of ecosystem responses to increasing climatic and anthropogenic pressures are needed to inform adaptation planning. However, data of appropriate spatiotemporal resolution are often not available to parameterize complex environmental processes at the global scale. Modeling approaches that can project the probability of ecosystem persistence when parameter uncertainty is high may offer a way forward. In particular, the conservation of coastal ecosystems with complex dynamics, like mangrove forests, may benefit from knowing where their future persistence is highly probable or, alternatively, cannot be reliably estimated without additional data of appropriate resolution. Here, we simulated network models to make probabilistic projections of the direction of net change in mangrove ecosystems worldwide under the SSP5-8.5 climate emissions scenario by the years 2040–2060. Seaward net loss was the most probable outcome in 77% [37%–78%; 95% confidence interval (CI)] of mangrove forest units, while 30% [15%–59%; CI] were projected to experience landward net gain or stability. In more than 50% of forest units, projections were ambiguous and therefore unreliable, with a near equal probability of net loss or gain. Quantitative models parameterized with locally accurate data could resolve uncertainty in the future persistence of mangroves in places with unreliable probabilistic projections. Projections made under conservation scenarios also showed that, with action to manage or restore, the number of mangrove forest units likely to experience net gain or stability in the future could nearly double. Our approach to simulating ecosystem responses to climatic and anthropogenic pressures provides a clear indication of how certain (or uncertain) ecosystem persistence is and thus can inform conservation planning.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70468","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144927227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid Climate Acclimation (Not Traits or Phylogeny) Drives Variation in Photosynthesis Temperature Response","authors":"Josef C. Garen,&nbsp;Sean T. Michaletz","doi":"10.1111/gcb.70474","DOIUrl":"https://doi.org/10.1111/gcb.70474","url":null,"abstract":"<p>Understanding variation in plant assimilation-temperature (AT) responses is essential for improving forecasts of climate change feedbacks and their impacts on the biosphere. Previous studies have focused on acclimation to weather or adaptation to climate of origin, but relationships between AT response parameters and leaf functional traits or phylogeny have received little attention. To evaluate the influence of climate, traits, and phylogeny on AT response, we used the new Fast Assimilation-Temperature Response (<i>FAsTeR</i>) gas exchange method to measure 243 AT response curves in 102 species from 96 families grown in a common garden. We also quantified climate variables, saturating light intensity, and key leaf functional traits. Local environmental conditions were the strongest predictors of AT response parameters. The optimal temperature for photosynthesis responded positively to recent air temperature and light exposure (partial <i>r</i>² = 0.27 and 0.53, respectively), and was best predicted by mean air temperature on the day of measurement; other AT parameters exhibited weak or no relationships with recent air temperature (all partial <i>r</i>² &lt; 0.1). AT response parameters showed no phylogenetic structure and only modest variation with leaf functional traits or climate of origin (all partial <i>r</i>² &lt; 0.07). Plant AT responses were primarily driven by acclimation to local climate variables, rather than adaptation to climate of origin. Thermal acclimation of photosynthesis occurred on much shorter timescales than expected (≤ 1 day). These findings underscore the need to account for rapid acclimation in Earth system models and climate change forecasts.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70474","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Estimation Approach of Net Carbon Sequestration Under Non-Continuous Flooding in Rice Fields","authors":"Jinyang Wang,&nbsp;Jianwen Zou","doi":"10.1111/gcb.70465","DOIUrl":"https://doi.org/10.1111/gcb.70465","url":null,"abstract":"&lt;p&gt;Hou et al. (&lt;span&gt;2025&lt;/span&gt;) conducted a meta-analysis of field studies from 2019 to 2023 to evaluate the effects of noncontinuous flooding (NCF) practices on net carbon sequestration (NCS) in rice fields. The authors concluded that compared with continuous flooding (CF), NCF substantially enhances ecosystem-scale NCS, primarily by reducing methane (CH&lt;sub&gt;4&lt;/sub&gt;) emissions while increasing photosynthetic carbon sequestration (PCS), despite a decrease in soil organic carbon (SOC) sequestration. This conclusion, however, warrants further scrutiny regarding methodological assumptions and data representativeness, potentially leading to a systematic overestimation of the carbon sequestration potential of NCF in rice systems.&lt;/p&gt;&lt;p&gt;A primary concern lies in the calculation framework applied to rice systems, where PCS was directly added as a carbon sink component in the NCS budget. PCS represents short-term carbon input via plant photosynthesis, most of which is harvested and rapidly returned to the atmosphere through consumption, combustion, or decomposition. In agricultural systems, only carbon stored long term in soils or stable organic pools is considered true sequestration (Smith et al. &lt;span&gt;2020&lt;/span&gt;). Treating PCS as ecosystem-level carbon sequestration conflates “carbon input” with “carbon retention,” thereby overstating the mitigation potential of carbon sequestration pathways in croplands. This approach also diverges from IPCC guidelines, which emphasize long-term carbon storage as the accounting basis (Ogle et al. &lt;span&gt;2019&lt;/span&gt;). Additionally, since SOC sequestration was estimated by comparing SOC content before and after a single growing season, part of the PCS might have already been reflected in the SOC increment. Adding both PCS and SOC sequestration therefore raises the possibility of double counting in Hou et al. (&lt;span&gt;2025&lt;/span&gt;). If the SOC change estimation method proposed by Guan et al. (&lt;span&gt;2023&lt;/span&gt;) is adopted, NCS should be calculated based on both the net ecosystem exchange during the rice growing season and non-CO&lt;sub&gt;2&lt;/sub&gt; greenhouse gas emissions.&lt;/p&gt;&lt;p&gt;SOC sequestration estimates themselves are also highly uncertain in Hou et al. (&lt;span&gt;2025&lt;/span&gt;). Single-season SOC comparisons are vulnerable to sampling error, spatial heterogeneity, and seasonal variability. Numerous studies have shown that detectable SOC changes require multi-year monitoring due to the slow turnover and delayed stabilization of carbon inputs (Smith et al. &lt;span&gt;2020&lt;/span&gt;). Due to the fact that most studies did not incorporate straw return or organic amendments, the reported SOC increase under CF, which exceeds 2800 kg CO&lt;sub&gt;2&lt;/sub&gt;-eq ha&lt;sup&gt;−1&lt;/sup&gt; in one season (see figure 7h, Hou et al. &lt;span&gt;2025&lt;/span&gt;), is unusually high. The values of SOC sequestration reported by Hou et al. (&lt;span&gt;2025&lt;/span&gt;) substantially exceed estimates from comparable field conditions without external carbon inputs (Lessmann et al. &lt;span&gt;2022&lt;/span","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 9","pages":""},"PeriodicalIF":12.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70465","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144927316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}