Global Change Biology最新文献

{"title":"Impacts of Climate-Land Dynamics on Global Population and Sub-Populations of a Desert Equid","authors":"Azita Rezvani,&nbsp;Mahmoud-Reza Hemami,&nbsp;Saeid Pourmanafi,&nbsp;Sima Fakheran,&nbsp;Petra Kaczensky","doi":"10.1111/gcb.70190","DOIUrl":"https://doi.org/10.1111/gcb.70190","url":null,"abstract":"<div>\u0000 \u0000 <p>Climate change and escalating land-use transformations pose a significant threat to global biodiversity by disrupting natural habitats. The Asiatic wild ass (<i>Equus hemionus</i>), a near-threatened species, faces various pressures across its Asian range. This study employs a niche modeling approach to assess suitable habitats for the Asiatic wild ass at both the global population and sub-population levels. The analysis integrates the impacts of climate scenarios and land use change across three temporal periods: past, present, and future. To investigate the uncertainty of climate models for the Asiatic wild ass habitat, we used two climate models, CMIP5 and CMIP6, at both global and sub-population levels. Niche overlap models were developed to examine patterns of niche similarity among sub-populations. The results demonstrate a severe decline in both suitable habitat area and the number of viable patches for all sub-populations. Projections reveal that the Mongolian wild ass and Indian wild ass endure the highest levels of isolation and habitat loss, alongside the extinct Syrian wild ass. Sub-population models often predict larger distributions compared to global population models using the same inputs. The outputs of the models indicate a severe decline in suitable habitat, underscoring the necessity of accounting for both ecological and conservation perspectives to understand species distribution dynamics. Our study highlights the need to consider both global population and sub-population levels in climate change assessments. These models provide essential guidance for conservation strategies by identifying suitable habitats and sites for reintroduction. Identifying habitat patches as refuges for large herbivores amidst land-use changes and climate fluctuations is crucial. Incorporating these patches into conservation planning is imperative for preserving biodiversity.</p>\u0000 </div>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875673","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":"Geographical and Environmental Factors Differentially Shape Planktonic Microbial Community Assembly and Resistomes Composition in Urban Rivers","authors":"Xin Liao,&nbsp;Hongjie Wang,&nbsp;Dong Wu,&nbsp;Hans-Peter Grossart,&nbsp;Xiaoyong Yang,&nbsp;Laiyi Li,&nbsp;Yuwen Wang,&nbsp;Shuang Li,&nbsp;Jiangwei Li,&nbsp;Meixian Cao,&nbsp;Nengwang Chen,&nbsp;Anyi Hu","doi":"10.1111/gcb.70211","DOIUrl":"https://doi.org/10.1111/gcb.70211","url":null,"abstract":"<div>\u0000 \u0000 <p>Global urbanization accelerates pollution challenges in urban rivers, including increased transmission of bacterial antibiotic resistance genes (ARGs), severely threatening the health of aquatic ecosystems and human health. Yet, systematic knowledge of differences in distribution and community assembly patterns of bacterial resistance across urban rivers at a continental scale is still insufficient. In this study, we conducted extensive sampling in nine representative urban rivers across China. We used amplicon and shotgun metagenomic sequencing, state-of-the-art bioinformatics, and multivariate statistics to investigate distribution patterns and community assembly mechanisms of planktonic microbiomes (i.e., bacterioplankton and planktonic microeukaryotes), including their resistomes, i.e., ARGs and metal resistance genes (MRGs). Geographical and environmental factors played a pivotal role in shaping distribution patterns of planktonic microbiomes vs. resistomes in the studied urban rivers. Phylogenetic-bin-based null model analysis (iCAMP) indicated that planktonic microbiomes, dominated by dispersal limitation and drift, tend toward spatial heterogeneity. In contrast, planktonic resistomes, driven by deterministic processes, display more similar distribution patterns. Cross-validated Mantel tests revealed that geographical factors (i.e., geographic distance) were the primary regulators of planktonic microbial community assembly, while environmental factors (i.e., temperature) control assembly processes of planktonic resistomes. Our findings provide crucial insights into the mechanisms driving the biogeographical distribution and community assembly of planktonic microbial entities in urban rivers at a continental scale, offering valuable implications for mitigating and managing the spread of ARGs from the environment to humans.</p>\u0000 </div>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875674","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":"Global Soil Methane Uptake Estimated by Scaling Up Local Measurements","authors":"Jiawei Jiang,&nbsp;Zhifeng Yan,&nbsp;Jinshi Jian,&nbsp;Shushi Peng,&nbsp;Hanqin Tian,&nbsp;Kendalynn A. Morris,&nbsp;Robert M. Ellam,&nbsp;Jesper Riis Christiansen,&nbsp;Huai Chen,&nbsp;Jianzhi Dong,&nbsp;Si-Liang Li,&nbsp;Pingqing Fu,&nbsp;Dabo Guan,&nbsp;Guirui Yu,&nbsp;Cong-Qiang Liu,&nbsp;Philippe Ciais,&nbsp;Ben Bond-Lamberty","doi":"10.1111/gcb.70194","DOIUrl":"https://doi.org/10.1111/gcb.70194","url":null,"abstract":"<div>\u0000 \u0000 <p>Aerobic soils remove methane from the atmosphere, but global soil methane uptake (SMU) estimates remain highly uncertain due to challenges in scaling local data. We develop a data-driven approach to refine this global estimate by incorporating local data of 79,800 flux measurements from 198 sites. This novel approach links the global SMU budget to local SMU fluxes by varying its parameters with soil properties. Our 2003–2018 global SMU estimate is ~39.0 Tg CH₄ year⁻¹—about 30% higher than existing bottom-up estimates and consistent with top-down assessments. Cold grasslands and deserts were found to contribute nearly 30% of the total SMU, while disturbed agricultural biomes have the lowest SMU. The projected future global SMU is shaped by temperature and atmospheric methane, though local SMU is primarily influenced by changes in soil moisture. This study emphasizes the potential of soils in climate regulation and highlights the need to focus on key biomes for a better understanding of the soil-atmosphere methane feedback and optimizing methane management strategies.</p>\u0000 </div>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871485","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":"Intertwined Relationship Between Soil pH and Microbes in Biogeography","authors":"Kai Feng,&nbsp;Ye Deng","doi":"10.1111/gcb.70208","DOIUrl":"https://doi.org/10.1111/gcb.70208","url":null,"abstract":"&lt;p&gt;Soil pH indicates the extent of acidity and alkalinity in terrestrial ecosystems and is one of the most important edaphic properties, greatly influencing nutrient availability, metal mobility, microbial growth, and ecosystem health. It is often considered the “master variable” in soil science because pH changes can cause a series of shifts, for example, the solubility changes of key ions such as phosphorus, aluminum, and calcium, could sequentially affect plant growth and microbial functioning (Weil and Brady &lt;span&gt;2016&lt;/span&gt;). Importantly, soil pH reflects the outcome of long-term interactions between climate, organisms, parent material, topology, and time. In the context of global change, soil pH is also variable. Precipitation regime shifts, warming-induced organic matter decomposition, acid deposition, and fertilization all contribute to pH fluctuations at multiple temporal and spatial scales (Philippot et al. &lt;span&gt;2023&lt;/span&gt;). Though soil pH generally maintains a relatively stable state via buffering systems such as aluminum compounds and carbonates, extreme shifts in pH can override this resilience, leading to cascading impacts on microbial communities and ecosystem stability. Understanding the mechanisms of the regulating factors and ecological consequences of soil pH changes and microbial life is essential for predicting terrestrial responses to climate change.&lt;/p&gt;&lt;p&gt;Over the past two decades, advanced developments in high-throughput sequencing have enabled new insights into the composition and structure of soil microbiomes across global biomes. Early continental-scale surveys demonstrated that soil pH was the best predictor of bacterial diversity and communities compared to other edaphic variables (Fierer and Jackson &lt;span&gt;2006&lt;/span&gt;). A meta-analysis has confirmed that bacterial diversity exhibits strong unimodal or linear relationships with pH, peaking in near-neutral conditions, and found a strong influence of soil pH on bacterial community assembly processes globally (Tripathi et al. &lt;span&gt;2018&lt;/span&gt;). These relationships are commonly observed across spatial scales and ecosystem types, from tundra to tropical forests. Therefore, most studies treat microbial communities as static responders to environmental gradients or changes. Our recent work (Feng et al. &lt;span&gt;2024&lt;/span&gt;) challenges this paradigm by demonstrating that core bacterial communities can serve as bioindicators of soil pH dynamics under future climate scenarios instead of just responders. The Core Bacteria Forecast Model (CoBacFM), integrating data from over 1,200 grassland sites globally, identified the biogeographic distributions of bacterial eco-clusters whose abundance was similarly shifted to environmental variables and forecast pH changes. The model projects that more than 60% of global grasslands will experience pH increases (alkalization) by 2100, particularly in regions like northeastern Asia, Oceania, and Africa. These predictions were supported by 14 g","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70208","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871486","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":"Future of Food Webs: The Role of Biotic Interactions in Predicting the Impact of Climate and Land Use Change","authors":"Anett Endrédi","doi":"10.1111/gcb.70202","DOIUrl":"https://doi.org/10.1111/gcb.70202","url":null,"abstract":"&lt;p&gt;The world we share with millions of species is changing rapidly and dramatically. Climate change, pollution, overexploitation, and the ongoing modification of natural habitats pose serious challenges for all species. Ecologists have always desired to predict the future of ecosystems and species. However, only recently have advanced modeling techniques and increased ecological data made it possible to use complex models to predict what will happen to communities over the next century.&lt;/p&gt;&lt;p&gt;Species distribution models (SDMs) attempt to predict where a species is likely to occur based on its relationship with environmental conditions. They can be used to predict how species' ranges will shift by considering different climate and land use change scenarios. However, species do not live independently of each other. A complex web of interactions links them, with direct and indirect effects spreading from one to another. The changing environment affects not only the species themselves but also the relationships between them (Van der Putten et al. &lt;span&gt;2010&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;Food web models are designed to investigate the structure and functioning of communities by focusing on one of the most important relationships: trophic interactions. The strength of these models is that they consider not only direct interactions between species but also indirect effects crossing multiple species. They are suitable for quantifying ecological processes such as productivity (Wang and Brose &lt;span&gt;2018&lt;/span&gt;) or the impacts of invasion and disturbances (e.g., Woodward and Hildrew &lt;span&gt;2001&lt;/span&gt;). Furthermore, they can be used to investigate important conservation issues, such as finding keystone species (Jordán et al. &lt;span&gt;2006&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;Previous studies have shown that climate change can strongly affect food webs. Differences in the species' thermal vulnerability and dispersal ability may lead to trophic mismatches (Thakur &lt;span&gt;2020&lt;/span&gt;) and the simplification and rewiring of food webs (Bartley et al. &lt;span&gt;2019&lt;/span&gt;). Land-use intensification may have similar effects, favouring particular trophic groups and inducing structural changes in food webs (Botella et al. &lt;span&gt;2024&lt;/span&gt;). An important question is, therefore, how these rearrangements will affect the structural properties of food webs and whether there are spatial patterns in which networks will be more sensitive to future environmental changes. Hao et al. (&lt;span&gt;2025&lt;/span&gt;) sought to answer this question in their ambitious research.&lt;/p&gt;&lt;p&gt;Large amounts of reliable ecological data are needed to compare food webs over time and space. However, collecting all the information about who eats whom in a community is difficult. Monitoring or measuring dietary preferences is time-consuming and sometimes expensive. One possible solution is to infer interactions based on the functional traits of the possibly interacting species. Eklöf et al. (&lt;span&gt;2013&lt;/span&gt;) showed that knowledge of a few relevant fu","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70202","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871487","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":"Sustainable Land Use Enhances Soil Microbial Respiration Responses to Experimental Heat Stress","authors":"Rémy Beugnon,&nbsp;Nico Eisenhauer,&nbsp;Alfred Lochner,&nbsp;Margarete J. Blechinger,&nbsp;Paula E. Buhr,&nbsp;Simone Cesarz,&nbsp;Monica A. Farfan,&nbsp;Olga Ferlian,&nbsp;Amanda J. Rompeltien Howard,&nbsp;Yuanyuan Huang,&nbsp;Blanca S. Kuhlmann,&nbsp;Nora Lienicke,&nbsp;Selma Mählmann,&nbsp;Anneke Nowka,&nbsp;Emanuel Petereit,&nbsp;Christian Ristok,&nbsp;Martin Schädler,&nbsp;Jonas T. M. Schmid,&nbsp;Lara J. Schulte,&nbsp;Kora-Lene Seim,&nbsp;Lise Thouvenot,&nbsp;Raphael Tremmel,&nbsp;Lara Weber,&nbsp;Jule Weitowitz,&nbsp;Huimin Yi,&nbsp;Marie Sünnemann","doi":"10.1111/gcb.70214","DOIUrl":"10.1111/gcb.70214","url":null,"abstract":"<p>Soil microbial communities provide numerous ecosystem functions, such as nutrient cycling, decomposition, and carbon storage. However, global change, including land-use and climate changes, affects soil microbial communities and activity. As extreme weather events (e.g., heatwaves) tend to increase in magnitude and frequency, we investigated the effects of heat stress on the activity (e.g., respiration) of soil microbial communities that had experienced four different long-term land-use intensity treatments (ranging from extensive grassland and intensive grassland to organic and conventional croplands) and two climate conditions (ambient vs. predicted future climate). We hypothesized that both intensive land use and future climate conditions would reduce soil microbial respiration (H1) and that experimental heat stress would increase microbial respiration (H2). However, this increase would be less pronounced in soils with a long-term history of high-intensity land use and future climate conditions (H3), and soils with a higher fungal-to-bacterial ratio would show a more moderate response to warming (H4). Our study showed that soil microbial respiration was reduced under high land-use intensity (i.e., −43% between extensive grassland and conventional cropland) and future climate conditions (−12% in comparison to the ambient climate). Moreover, heat stress increased overall microbial respiration (+17% per 1°C increase), while increasing land-use intensity reduced the strength of this response (−25% slope reduction). In addition, increasing soil microbial biomass and fungal-to-bacterial ratio under low-intensity land use (i.e., extensive grassland) enhanced the microbial respiration response to heat stress. These findings show that intensive land use and climate change may compromise the activity of soil microbial communities as well as their respiration under heatwaves. In particular, soil microbial communities under high-intensity land use and future climate are less able to respond to additional stress, such as heatwaves, potentially threatening the critical ecosystem functions driven by soil microbes and highlighting the benefits of more sustainable agricultural practices.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70214","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866993","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":"Sea-Ice Retreat From the Northeast Greenland Continental Shelf Triggers a Marine Trophic Cascade","authors":"Jack H. Laverick,&nbsp;Douglas C. Speirs,&nbsp;Michael R. Heath","doi":"10.1111/gcb.70189","DOIUrl":"https://doi.org/10.1111/gcb.70189","url":null,"abstract":"<p>Climate change is causing sea-ice to retreat from Arctic ecosystems. Loss of ice impacts the ecosystem in many ways, reducing habitat area for specialist species like polar bears, releasing freshwater and nutrients, and increasing light penetration into the water column. To explore the interaction of these effects, we implemented a Northeast Greenland continental shelf parameterisation of the end-to-end ecosystem model StrathE2E. We used model output from the NEMO-MEDUSA ocean-biogeochemistry model under Representative Concentration Pathway 8.5 as driving data, which suggests the northeast Greenland continental shelf will become seasonally ice-free by 2050. We simulated half a century of climate change by running the model system to a set of steady states for each decade from the 2010s to the 2050s. Our simulations show sea-ice retreat from the northeast Greenland continental shelf boosts the productivity of the marine food web. Total living mass increases by over 25%, with proportionally larger increases for higher trophic levels. The exception to this is a 66% reduction in maritime mammal mass. Additional network indices reveal that the ecosystem becomes more mature, with future diets more specialized and a lengthening of the food web. Our model provides long-term strategic insight for the management of the northeast Greenland continental shelf, allowing for the quantitative evaluation of conservation goals and the scale of prospective fisheries. Our results present a mixed picture for the future of the Arctic, with growing populations for fish and charismatic megafauna like cetaceans accompanied by the loss of endemic biodiversity such as polar bears.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70189","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865848","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 Forest After Tomorrow: Projecting the Impact of a Collapsing Atlantic Meridional Overturning Circulation on European Tree-Species Distributions","authors":"Sina Heubel,&nbsp;Anja Rammig,&nbsp;Allan Buras","doi":"10.1111/gcb.70185","DOIUrl":"https://doi.org/10.1111/gcb.70185","url":null,"abstract":"<p>Forest tree species are expected to experience a substantial redistribution due to climate change. While previous work has emphasized the effects of a warmer and drier climate on European tree-species distributions, to date no study has investigated the potential impact of a collapse of the Atlantic Meridional Overturning Circulation (AMOC). Here, we deploy climate-envelope models to quantile mapped, high-resolution (1km²) CMIP6 climate projections and compare tree-species distributions under an active AMOC vs. an inactive AMOC scenario. Across Europe, our tree-species projections indicate contrasting impacts of the two scenarios. In Scandinavia, many of the currently abundant tree species were projected a dramatic decline and partial disappearance due to the strong cooling under an inactive AMOC. In Central and Southern Europe, however, some of the currently abundant species suffered less under an inactive AMOC compared to an active AMOC scenario while others—such as the economically important species of Norway spruce—almost went extinct. As opposed to the classic climate-change scenario supporting Mediterranean species in Central Europe, projected European tree-species portfolios consisted of a higher share of boreal, cold-tolerant species in the inactive AMOC scenario. Finally, tree-species diversity was projected to decline even stronger under an inactive vs. an active AMOC scenario. Altogether, while an AMOC collapse may locally result in more favorable conditions for specific species in comparison to a classic climate-change scenario, the dramatic economic and ecological consequences suggested by our projections indicate the urgent need for climate-change mitigation to lower the likelihood of an AMOC collapse.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70185","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865847","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":"Stronger Drought Response of CO2 Fluxes in Tundra Heath Compared to Sphagnum Peatland in the Sub-Arctic","authors":"Valentin Heinzelmann,&nbsp;Julia Marinissen,&nbsp;Rien Aerts,&nbsp;J. Hans C. Cornelissen,&nbsp;Stef Bokhorst","doi":"10.1111/gcb.70210","DOIUrl":"10.1111/gcb.70210","url":null,"abstract":"<p>Drought events are increasing in frequency and intensity due to climate change, causing lasting impacts on plant communities and ecosystem functioning. In the sub-arctic, climate is changing at a rate above the global average with amplifying effects on the carbon cycle. Drought-induced shifts in the balance between productivity and respiration might have important implications for climate change feedbacks in these regions. However, little is known about how carbon fluxes in sub-arctic ecosystems respond to drought, hampering predictions. Here, we test how two important but contrasting sub-arctic ecosystem types, <i>Sphagnum</i> peatland and tundra heath, respond to experimental drought. Mesocosms were exposed to a full precipitation exclusion for 7 weeks, decreasing gravimetric water content by 66% and 53% for <i>Sphagnum</i> peatland and tundra heath, respectively. Drought suppressed all CO₂ flux components. Gross primary productivity was on average reduced by 47% and 64%, and ecosystem respiration by 40% and 53% in <i>Sphagnum</i> peatland and tundra heath, respectively. Concomitantly with the ecosystem fluxes, leaf photosynthesis of the three most abundant vascular plant species per ecosystem type was on average suppressed by 40% (peatland) and 77% (tundra heath). Drought resulted in high plant mortality, with up to 54% (peatland) and 73% (tundra heath) dead shoots, which might represent a significant legacy effect suppressing CO₂ uptake in subsequent growing seasons. In summary, tundra heath was overall more responsive to drought than peatland. This differential sensitivity, previously unaccounted for, might be important in the future under intensifying drought events. Considering that tundra heath covers more than half of the sub-arctic land area, its drought responsiveness might induce significant reductions in total arctic net CO₂ uptake. This would move the arctic carbon balance further toward a net CO₂ source.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866996","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":"Alleviating Nitrogen and Phosphorus Limitation Does Not Amplify Potassium-Induced Increase in Terrestrial Biomass","authors":"Guopeng Liang,&nbsp;梁国鹏,&nbsp;Pengyan Sun,&nbsp;孙鹏燕,&nbsp;Bonnie G. Waring,&nbsp;Zheng Fu,&nbsp;Peter B. Reich","doi":"10.1111/gcb.70193","DOIUrl":"https://doi.org/10.1111/gcb.70193","url":null,"abstract":"<p>Potassium (K) is the second most abundant nutrient element in plants after nitrogen (N), and has been shown to limit aboveground production in some contexts. However, the role of N and phosphorus (P) availability in mediating K limitation in terrestrial production remains poorly understood; and it is unknown whether K also limits belowground carbon (C) stocks, which contain at least three times more C than those aboveground stocks. By synthesizing 779 global paired observations (528, 125, and 126 for aboveground productivity, root biomass, and soil organic C [SOC], respectively), we found that K addition significantly increased aboveground production and SOC by 8% and 5%, respectively, but did not significantly affect root biomass (+9%). Moreover, enhanced N and/or P availability (through N and P addition) did not further amplify the positive effect of K on aboveground productivity. In other words, K had a positive effect on aboveground productivity only when N and/or P were limiting, indicating that K could somehow substitute for N or P when they were limiting. Climate variables mostly explained the variations in K effects; specifically, stronger positive responses of aboveground productivity and SOC to K were found in regions with high mean annual temperature and wetness. Our results suggest that K addition enhances C sequestration by increasing both aboveground productivity and SOC, contributing to climate mitigation, but the positive effects of K on terrestrial C stocks are not further amplified when N and P limitations are alleviated.</p>","PeriodicalId":175,"journal":{"name":"Global Change Biology","volume":"31 4","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.70193","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865606","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}