Climate-driven upward spread of forest fires in European mountain regions

Climate-driven upward spread of forest fires in European mountain regions | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Climate-driven upward spread of forest fires in European mountain regions Mirela Beloiu Schwenke, Tomoki Loeillot, Verena Griess, Dimitris Poursanidis, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7658014/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Forest fires are becoming increasingly frequent and seriously threaten European mountain regions. However, changes in the elevational distribution of forest fires in European mountain regions and their drivers remain largely unknown. Using remote sensing and climatic time series (2000–2022) combined with statistical approaches, we found that large forest fires (> 30 ha) are spreading upwards and are becoming more frequent at high elevations, notably from 2015 to 2022. Changes in burned area were mostly driven by climatic drivers (R² = 0.39), including vapor pressure deficit (VPD), soil moisture, and precipitation, suggesting that further warming could make European mountain regions increasingly fire prone. Whereas fires below 1,400 m occurred under a broad range of climatic conditions, fire occurrences above this threshold were enabled by extreme atmospheric aridity, underscoring that climate change is expanding fire into ecosystems historically buffered from burning. Our results indicate that understanding fire activity in mountain regions in the context of changing climate is essential for effective fire management and preservation of mountain ecosystem functions and services. Earth and environmental sciences/Ecology/Fire ecology Earth and environmental sciences/Ecology/Forest ecology Earth and environmental sciences/Ecology/Climate-change ecology Full Text Additional Declarations There is NO Competing Interest. Supplementary Files 20250908SupplementaryMaterialsNG.docx Supplementary materials Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7658014","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":518817477,"identity":"2589d84f-33c4-4fbc-9737-d4159dfab676","order_by":0,"name":"Mirela Beloiu Schwenke","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFElEQVRIie3RMUvEMBTA8VcC6dLa9bmoX0AICC4K91VeJrdbblE4jkIhtzkrHn6GTuJmQqDTSdcODieuDnWRm8S0dLiDa7lRMH+SDiE/XiEAPt9fjLm9AiAIATRcd6dB6j44QKhZrCHL7tQMEdggEKg9yOk8fl/RFMYJY8bGj3YkSh18fD3PIHlId5JzG54JKmBymHGy8ZOVeUVMmCUHfNM9hHMkDjK3kWgIiQo4GhWBQOoj4Zp+QL60ZNH+WLg2CoeIG6HcFNaQ1Aa5dkONEkOEobzFCVpOZlFcyftKZviqKMKqh5RFUNffl+Nkntn6c3oxOiitqW/U7Ci52026Np7gRLdPD9HQ/e2O0/3v+nw+3//oFxkwYBczSrRQAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-3592-8170","institution":"ETH Zurich","correspondingAuthor":true,"prefix":"","firstName":"Mirela","middleName":"Beloiu","lastName":"Schwenke","suffix":""},{"id":518817478,"identity":"5af7d3c1-075e-4756-8fd3-dfb7e450d382","order_by":1,"name":"Tomoki Loeillot","email":"","orcid":"","institution":"ETH Zurich, Department of Environmental System Sciences, Institute of Terrestrial Ecosystems","correspondingAuthor":false,"prefix":"","firstName":"Tomoki","middleName":"","lastName":"Loeillot","suffix":""},{"id":518817479,"identity":"6b7db780-049a-461f-b063-0f428fdaf694","order_by":2,"name":"Verena Griess","email":"","orcid":"https://orcid.org/0000-0002-3856-3736","institution":"ETH Zurich","correspondingAuthor":false,"prefix":"","firstName":"Verena","middleName":"","lastName":"Griess","suffix":""},{"id":518817480,"identity":"58a0d3b8-b291-4d1f-83f5-03a19a84692e","order_by":3,"name":"Dimitris Poursanidis","email":"","orcid":"","institution":"Foundation for Research and Technology Hellas, Institute of Applied and Computational Mathematics, 100 N. 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However, changes in the elevational distribution of forest fires in European mountain regions and their drivers remain largely unknown. Using remote sensing and climatic time series (2000\u0026ndash;2022) combined with statistical approaches, we found that large forest fires (\u0026gt;\u0026thinsp;30 ha) are spreading upwards and are becoming more frequent at high elevations, notably from 2015 to 2022. Changes in burned area were mostly driven by climatic drivers (R\u0026sup2; = 0.39), including vapor pressure deficit (VPD), soil moisture, and precipitation, suggesting that further warming could make European mountain regions increasingly fire prone. Whereas fires below 1,400 m occurred under a broad range of climatic conditions, fire occurrences above this threshold were enabled by extreme atmospheric aridity, underscoring that climate change is expanding fire into ecosystems historically buffered from burning. 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