Union-wide
Community-led
Inter- and Transdisciplinary Sessions
Disciplinary sessions

BG – Biogeosciences

Programme Group Chair: Lisa Wingate

MAL33-BG
Vladimir Ivanovich Vernadsky Medal Lecture by Corinne Le Quéré and BG Division Outstanding ECS Award Lecture by Getachew Agmuas Adnew
Convener: Lisa Wingate

BG1 – General Biogeosciences

Sub-Programme Group Scientific Officer: Lisa Wingate

BG1.1 EDI

Fire is the main terrestrial ecosystem disturbance globally and a critical Earth system process. Fire research is rapidly expanding across disciplines, highlighting the need to advance our understanding of how fire interacts with land, atmosphere and society. This need is growing as fire activity increases in many world regions. This session invites contributions that investigate the role of fire within the Earth system across any spatiotemporal scale, using statistical (including AI) and process-based models, field and laboratory observations, proxy records, remote sensing, and data-model fusion techniques. We strongly encourage abstracts on fire's interactions with: (1) weather, climate, atmospheric chemistry, and circulation, (2) land physical properties, (3) vegetation composition and structure and biogeochemical cycle, (4) cryosphere elements and processes (such as permafrost, sea ice), and (5) human health, land management, conservation, and livelihoods. Moreover, we welcome submissions that address: (6) spatiotemporal changes in fire in the past, present, and future, 7) fire products and models, and their validation, error/bias assessment and correction, as well as (8) analytical tools designed to enhance situational awareness for fire practitioners and to improve fire early warning systems.

Co-organized by AS4/NH14
Convener: Sander Veraverbeke | Co-conveners: Yang Li, Angelica Feurdean, Antonio Girona-GarcíaECSECS, Renata Libonati, Fang Li
BG1.2 EDI

The Paris Agreement on Climate sets the international objective of reducing greenhouse gas (GHG) emissions to keep climate warming well below two degrees. However, quantifying past and present GHG emissions and sinks and predicting their future remains a substantial challenge. This challenge is primarily due to the high level of uncertainties in observing and modeling these GHG fluxes at regional to global scales. Thus, achieving climate and emission reduction targets requires a substantial improvement in our scientific ability to estimate the budgets and trends of these key major greenhouse gases (CO2, CH4 and N2O).

This session aims to bring together studies that seek to quantify past, present, and future global and regional budgets, trends and variability of major GHGs, as well as studies that contribute to understanding the key drivers and processes controlling their variations. We welcome contributions using a variety of approaches, such as emissions inventories, field and remotely sensed observations, terrestrial and ocean biogeochemical modeling, earth system modeling, and atmospheric inverse modeling. We encourage contributions integrating different datasets and approaches at multiple spatial (regional to global) and temporal scales (from past over the present and to the future) that provide new insights on processes influencing GHG budgets and trends in the past and future.

Solicited authors:
Jens Daniel Müller,Santiago Botía
Co-organized by AS3/OS1
Convener: Jens TerhaarECSECS | Co-conveners: Yohanna VillalobosECSECS, Marta López-MozosECSECS, Ronny Lauerwald, Ana Bastos
BG1.3 EDI

Anthropogenic disturbance of the global nitrogen (N) cycle has more than doubled the amount of reactive N circulating in the terrestrial biosphere alone. Exchange of reactive/non-reactive nitrogen gases between land and atmosphere including reactive N deposition on ecosystems are strongly affecting Earth’s atmospheric composition, air quality, global warming, climate change, human health and biodiversity. This session seeks to improve our understanding of a) how intensification of reactive N use, land management and climate change affects the pools and fluxes of nitrogen in terrestrial and aquatic ecosystems, b) and how reactive N enrichment of land and water will affect the future carbon sink of natural ecosystems as well as atmospheric exchanges of reactive (NO, N2O, NH3, HONO, NO2 and non-reactive N (N2) gases with implications for global warming, climate change and air quality, and c) how fluxes, in particular N deposition, can be quantified with the necessary accuracy to be used in nature protection policies as well as emission regulation and mitigation strategies. We welcome contributions covering a wide range of experimental and modelling studies, which covers microbes-mediated and physico-chemical transformations and transport of nitrogen across the land-water-air continuum in natural ecosystems from local to regional and global scales. Furthermore, the interactions of nitrogen with other elemental cycles (e.g. phosphorus, carbon) and the impacts of these interactive feedbacks for soil health, biodiversity and water and air quality will be explored in this session. Latest developments in methodological innovations and observational and experimental approaches for unravelling the complexities of nitrogen transformations and transport will also be of interest. This session will be celebrating its 10th anniversary for nitrogen science and cycling at the EGU2025.

Co-organized by AS2/SSS5
Convener: Sami Ullah | Co-conveners: Ana Meijide, Alexander Moravek, Sabine Banzhaf, Paul Hamer, Li LiECSECS, Tuula Larmola
BG1.4 EDI

In recent decades, extreme fire events have become increasingly common, exemplified by the recent fire seasons in Greece, Canada, Hawaii, California, Australia, Amazonia, the Arctic and the Pantanal. While these extremes and megafires have an exponential impact on society and all aspects of the Earth system, there is much to learn about their characteristics, drivers, links to climate change, and how to quantify their impacts, as well as mitigation and prevention strategies and tools.

One area of attention is how extreme fires are currently represented by different fire models. Due to their stochastic nature, uncertainty in observations, and the challenge of representing local processes within global models, extreme fires and their impacts still present a challenge to coupled modelling. The big data science models and machine learning approaches show promise in representing extremes but are weak in coupling feedbacks to vegetation, soils and the wider Earth System.

We also welcome case studies of regional extreme wildfire events, their impacts, and prevention and mitigation strategy experiences worldwide. We encourage contributions from a wide range of disciplines, including global, regional, and landscape modelling, statistical and process-based modelling, observations and field studies, science and social science studies on all temporal scales. In this session, we aim to share knowledge across multiple disciplines, from science to decision-makers and practitioners, to help overcome the challenges that wildfires pose to our models and our society.

We aim to explore the significance and interactions of extreme wildfires and their impacts on society and the earth system and identify the current gaps in our understanding to help us prepare for and mitigate future extreme wildfire events.

Solicited authors:
Matthew Jones
Co-organized by CL3.2/NH14
Convener: D. I. Kelley | Co-conveners: Chantelle BurtonECSECS, Francesca Di Giuseppe, Liana O. Anderson, Stijn Hantson
BG1.6 EDI

Dissolved and particulate organic carbon (DOM, POM) are key components of the global carbon cycle and are important as potential sources of CO2 and CH4, and for the long-term preservation of carbon stabilized in subsoils and sediments. DOM and POM are important sources of energy for microbial metabolism within terrestrial ecosystems, the aquatic continuum, and, ultimately, the ocean. Despite recent evidence showing this lateral transport of carbon is linked to anthropogenic perturbations, efforts to integrate DOM and POM fluxes across the terrestrial-aquatic continuum are just emerging. A comprehensive understanding of the dynamics of DOM and POM, and their interactions, in terrestrial and aquatic ecosystems remains challenging due to complex interactions of biogeochemical and hydrological processes at different scales, i.e. from the molecular to the landscape scale.
This session aims to improve our understanding of organic matter processing at the interface of terrestrial and aquatic ecosystems. We solicit contributions dealing with amounts, composition, reactivity, and fate of DOM and POM and the stoichiometry of its constituents (i.e., C, N, P, S) in soils, lakes, rivers, and the ocean as well as the impact of land use change and climatic change on these processes. For example, when assessing carbon dynamics across the terrestrial-aquatic continuum, it is important to recognize the key role of peatlands and peat restoration efforts as sources of organic matter for streams and rivers, as well as the contribution of mineral soil horizons to C fluxes at the catchment scale. Contributions addressing lateral fluxes of sediment and carbon induced by soil erosion or permafrost thaw are also welcome. We aim to bring together scientists from various backgrounds, but all devoted to the study of dissolved and/or particulate organic matter using a broad spectrum of methodological approaches (e.g. molecular, spectroscopic, isotopic, 14C, other tracers, and modeling).

Solicited authors:
Daniel Graeber
Co-organized by HS13/SSS5
Convener: Karsten Kalbitz | Co-conveners: Dolly Kothawala, Núria Catalán García, Jorien Vonk
BG1.7 EDI

Phosphorus (P) is an essential element for life on Earth and is tightly cycled within the biosphere. Throughout geological history, P availability has regulated biological productivity with impacts on the global carbon cycle. Today, human activities are significantly changing the natural cycling of P. Phosphate mining threatens P reserves, while increased inputs of P to terrestrial ecosystems have enhanced fluxes of P to lakes and the oceans.

Direct anthropogenic perturbations of the P cycle, coupled with other human-induced stresses, have impacted numerous environments. Forest ecosystems may be losing their ability to recycle P efficiently, due to excessive N input, extensive biomass removal, and climatic stress. Soils, which serve as the biogeochemical fulcrum of the terrestrial P cycle, have been greatly altered by fertilizer use in recent decades. Changes in the P cycle on land impact the magnitude and timing of P fluxes into aquatic ecosystems, influencing their trophic state. Burial in sediments returns P to the geological reservoir, eventually forming economically viable P deposits. Throughout the P cycle, redox conditions play a key role in transformations and mobility of P. Climate change and its mitigation affect and will further disrupt global P cycles. For example, the removal of CO2 from the atmosphere through an increase in global soil organic carbon stocks implies P sequestration.

This interdisciplinary session invites contributions to the study of P from all disciplines, and aims to foster collaborations links between researchers working on different aspects of the P cycle. We target a balanced session giving equal weight across the continuum of environments in the P cycle, from agriculture, forests, soils and groundwater, through lakes, rivers and estuaries, to oceans, marine sediments and geological P deposits. We welcome both empirical and modeling studies.

Co-organized by OS3/SSS5
Convener: Nelly Sophie RaymondECSECS | Co-conveners: Julian HelfensteinECSECS, Sonya Dyhrman, David O'Connell, Tom Jilbert
BG1.8 EDI

Mercury (Hg) pollution, stemming from both intentional use and unintentional emissions, poses a global threat to human health and wildlife. The urgency of this issue has led 149 countries to join the Minamata Convention on Mercury, which has been in effect since 2017 and is currently undergoing its first effectiveness evaluation. Research into Hg biogeochemical cycling has revealed its ubiquity and complex transformations across various environmental compartments, including the atmosphere, oceans, cryosphere, soils, vegetation, biota, and the anthroposphere. Understanding the future trajectory of Hg pollution and its environmental impacts requires an in-depth knowledge of the processes occurring within and between these compartments. This session invites studies that investigate Hg cycling within individual compartments, as well as studies that explore inter-compartmental interactions and their influence on the Hg cycle. Topics of interest include, but are not limited to, air-surface exchanges of Hg compounds, Hg (de)-methylation and bioaccumulation, sea ice processing, and climate/global change impacts on Hg cycling. We welcome presentations utilizing diverse methodologies, including laboratory experiments, field studies, mechanistic or statistical modelling, paleoenvironmental records, genomics, Hg stable isotopes, and emissions projections. Additionally, this session encourages contributions that aim to inform policy, including those associated with the Multi-Compartment Hg Modeling and Analysis Project (MCHgMAP).

Convener: Aryeh FeinbergECSECS | Co-conveners: Hélène Angot, Alkuin Maximilian Koenig, Sae Yun Kwon, Chuxian LiECSECS
CL2.4

Phenological changes induced by ongoing climate change are affecting species, ecosystems, and even the global climate by altering species performance, species interactions (potential mismatches and new opportunities in the food web), and water and carbon cycles. Observations of plant and animal phenology as well as remote sensing and modeling studies document complex interactions and raise many open questions about the future sustainability of species and ecosystems. In this session we invite all contributions that address seasonality changes based on plant and animal phenological observations, pollen monitoring, historical documentary sources, or seasonality measurements using climate data, remote sensing, flux measurements, modeling studies or experiments. We also welcome contributions addressing cross-disciplinary perspectives and international collaborations and program-building initiatives including citizen science networks and data analyses from these networks.
This session is organized by a consortium representing the International Society of Biometeorology (Phenology Commission), the Pan-European Phenology Network - PEP725, the Swiss Academy of Science SCNAT, the TEMPO French Phenology Network and the USA National Phenology Network.

Co-organized by BG1
Convener: Yann VitasseECSECS | Co-conveners: Barbara Templ, Alison Donnelly, Hans Ressl, Iñaki Garcia de Cortazar-AtauriECSECS
CL4.14 EDI | PICO

The interactions between aerosols, climate, weather, and society are among the large uncertainties of current atmospheric research. Mineral dust is an important natural source of aerosol with significant implications on radiation, cloud microphysics, atmospheric chemistry, and the carbon cycle via the fertilization of marine and terrestrial ecosystems. Together with other light-absorbing particles, dust impacts snow and ice albedo and can accelerate glacier melt. In addition, properties of dust deposited in sediments and ice cores are important (paleo-)climate indicators.

This interdivisional session -- building bridges between the EGU divisions AS, CL, CR, SSP, BG and GM -- had its first edition in 2004 and it is open to contributions dealing with:

(1) measurements of all aspects of the dust cycle (emission, transport, deposition, size distribution, particle characteristics) with in situ and remote sensing techniques,
(2) numerical simulations of dust on global, regional, and local scales,
(3) meteorological conditions for dust storms, dust transport and deposition,
(4) interactions of dust with clouds and radiation,
(5) influence of dust on atmospheric chemistry,
(6) fertilization of ecosystems through dust deposition,
(7) interactions with the cryosphere, including also aerosols other than dust,
(8) any study using dust as a (paleo-)climate indicator, including sediment archives in loess, ice cores, lake sediments, ocean sediments and dunes,
(9) impacts of dust on climate and climate change, and associated feedbacks and uncertainties,
(10) implications of dust for health, transport, energy systems, agriculture, infrastructure, etc.

We especially encourage the submission of papers that integrate different disciplines and/or address the modelling of past, present, and future climates.

We are delighted to announce that in the 22nd edition of the dust session, Dr Patricia Castellanos (NASA) will provide a solicited talk about her work on airborne observations of dust.

Solicited authors:
Patricia Castellanos
Co-organized by AS3/BG1/CR5/GM6
Convener: Jan-Berend Stuut | Co-conveners: Claire Ryder, Clarissa BaldoECSECS, Martina Klose

BG0 – Inter- and Transdisciplinary Sessions

Sub-Programme Group Scientific Officer: Lisa Wingate

EOS3.1 EDI

Following the success of previous years, this session will explore reasons for the under-representation of different groups (gender identities, sexual orientations, racial and cultural backgrounds, abilities, religions, nationality or geography, socioeconomic status, ages, career stages, etc.) by welcoming debate among scientists, decision-makers and policy analysts in the geosciences.

The session will focus on both obstacles that contribute to under-representation and on best practices and innovative ideas to remove those obstacles. Contributions are solicited on the following topics:

- Role models to inspire and further motivate others (life experience and/or their contributions to promote equality)
- Imbalanced representation, preferably supported by data, for awards, medals, grants, high-level positions, invited talks and papers
- Perceived and real barriers to inclusion (personally, institutionally, culturally)
- Recommendations for new and innovative strategies to identify and overcome barriers
- Gender Equality Plans (GEP) in European host institutions: the good, the bad, and the ugly
- Best practices and strategies to move beyond barriers, including:
• successful mentoring programmes;
• networks that work;
• specific funding schemes;
• examples of host institutions initiatives;

Report on situations that you may have experienced in light of recent socio-political changes.

This session is co-organised with the support of the European Research Council (ERC).

Co-organized by AS6/BG0/GD11/GM11/OS5/PS0/SSS12, co-sponsored by AGU and JpGU
Convener: Claudia Jesus-Rydin | Co-conveners: Stefanie Kaboth-BahrECSECS, Alberto Montanari, Hori, S. Rie, Billy Williams
EOS4.8 EDI

Sitting under a tree, you feel the spark of an idea, and suddenly everything falls into place. The following days and tests confirm: you have made a magnificent discovery — so the classical story of scientific genius goes…

But science as a human activity is error-prone, and might be more adequately described as "trial and error", or as a process of successful "tinkering" (Knorr, 1979). Thus we want to turn the story around, and ask you to share 1) those ideas that seemed magnificent but turned out not to be, and 2) the errors, bugs, and mistakes in your work that made the scientific road bumpy. What ideas were torn down or did not work, and what concepts survived in the ashes or were robust despite errors? We explicitly solicit Blunders, Unexpected Glitches, and Surprises (BUGS) from modeling and field or lab experiments and from all disciplines of the Geosciences.

Handling mistakes and setbacks is a key skill of scientists. Yet, we publish only those parts of our research that did work. That is also because a study may have better chances to be accepted for publication in the scientific literature if it confirms an accepted theory or if it reaches a positive result (publication bias). Conversely, the cases that fail in their test of a new method or idea often end up in a drawer (which is why publication bias is also sometimes called the "file drawer effect"). This is potentially a waste of time and resources within our community as other scientists may set about testing the same idea or model setup without being aware of previous failed attempts.

In the spirit of open science, we want to bring the BUGS out of the drawers and into the spotlight. In a friendly atmosphere, we will learn from each others' mistakes, understand the impact of errors and abandoned paths onto our work, and generate new insights for our science or scientific practice.

Here are some ideas for contributions that we would love to see:
- Ideas that sounded good at first, but turned out to not work.
- Results that presented themselves as great in the first place but turned out to be caused by a bug or measurement error.
- Errors and slip-ups that resulted in insights.
- Failed experiments and negative results.
- Obstacles and dead ends you found and would like to warn others about.

--
Knorr, Karin D. “Tinkering toward Success: Prelude to a Theory of Scientific Practice.” Theory and Society 8, no. 3 (1979): 347–76.

Solicited authors:
Jan Seibert
Co-organized by BG0/EMRP1/ESSI4/GD10/GI1/GI6/GM11/GMPV1/PS0/SM2/SSS11/ST4
Convener: Ulrike ProskeECSECS | Co-conveners: Laetitia Le Pourhiet, Daniel KlotzECSECS, Nobuaki Fuji, Jonas PyschikECSECS
ITS1.7/BG0.3 EDI

Join us for an interdisciplinary session, where we will explore how cutting-edge omics technologies are transforming our understanding of ecosystems and their resilience in response to climatic change across all scales. Over billions of years, spatial and temporal shifts in environmental conditions have driven the evolution of diverse microbial, fungal, plant and animal species, shaping the ecosystems, atmosphere, and climate of Earth. Gaining insights into how these organisms and biomes function, adapt, and interact requires a deep understanding of their components and the complex feedback systems they form.

Technological innovations in measuring and interpreting “meta-omics” datasets are now providing unprecedented mechanistic insights across diverse organisms, scales, and environmental spheres. These advances also drive the development of next-generation models to predict ecosystem function. In this session, we bring together ecologists, geochemists, and evolutionary biologists to examine the available omics toolkits for studying organisms and communities and to discuss ongoing efforts to integrate this knowledge across biological and temporal scales to address pressing Earth system science questions.

By combining eco-evolutionary insights with ecosystem-level concepts like community traits and resilience, we aim to foster future ITS sessions that apply integrated omics approaches alongside geoscience techniques for a deeper, mechanistic understanding of ecosystems.

We welcome contributions studying all Earth’s spheres (Biosphere, Atmosphere, Hydrosphere, Cryosphere, Geosphere), using a wide range of omics datasets (metagenomics, metatranscriptomics, metabolomics, proteomics, lipidomics, spectranomics, ionomics, elementomics, and isotopomics) as well as other large datasets such as trait, phenotype, inventory, pollen, and fossil records. We are particularly interested in studies involving control experiments, long-term ecological surveys, or flux networks, as well as research that provides mechanistic insights and employs big data in Earth system models or machine learning to scale patterns across space and time.

Convener: Christoph Keuschnig | Co-conveners: Elsa AbsECSECS, Abraham Dabengwa, Lisa Wingate
ITS1.8/BG0.4 EDI

Advances in forest system modelling and monitoring techniques are crucial for deepening our understanding of forest ecosystems and their dynamic responses to environmental stresses and disturbances. These advancements are instrumental in addressing global environmental challenges by improving predictions and adapting management strategies accordingly. This session aims to bring together scientists and researchers focused on the latest advancements in forest systems modelling, observational techniques, and analytical methodologies to enhance our understanding of forest structural dynamics, soil carbon (C) dynamics, and the impacts of natural disturbances such as wildfires, insect’s outbreaks, pathogens/disease, droughts, and windstorms. Specifically, this session covers the following topics:

• Advancements in Forest System Modelling: Presentations on new models or significant improvements in existing models, that help predict and analyse forest growth, structural dynamics, C sequestration in biomass and soils, and ecosystem resilience. This includes models that integrate hydrological, meteorological, and biological processes.

• Innovative Monitoring Techniques: Studies showcasing novel observational technologies or methodologies, including remote sensing, isotopic tracing, or ground-based monitoring systems that provide new insights into forest mortality, growth patterns, and C cycling.

• Impact of Natural Disturbances: Research on how wildfires, insect’s outbreaks, pathogens/disease, droughts, and severe wind events alter forest structure, soil C stocks, and overall ecosystem functions. Contributions may include forward-looking information, post-disturbance recovery processes, disturbance modelling, and strategies for disturbance mitigation and adaptation.

• Cross-Scale Integration: Contributions that demonstrate the integration of innovative integrations of data and models across different spatial and temporal scales to understand forest biomass and soil dynamics comprehensively.

• Implications for future Management Strategies: Insights into how advanced modelling and monitoring approaches can shape policy development, offer a range of adaptation strategies, and inform management practices to enhance forest resilience and C retention.

Convener: Andre (Mahdi) NakhavaliECSECS | Co-conveners: Fulvio Di Fulvio, Melania Michetti, Daniela Dalmonech, Manfred Lexer
ITS2.7/BG0.5 EDI

Disturbances, such as extreme weather events, play a key role in shaping ecosystems. Under climate change, extreme weather hazards undergo changes in frequency, intensity and seasonality. While ecosystem-based adaptation and nature-based solutions are gaining traction, it is crucial to elucidate the diverse interactions between extreme weather risk, ecosystems, and their services.

This session seeks to highlight research on the nexus of extreme weather events and ecosystems. This includes: 1) investigations into the key attributes and patterns of extreme weather events which affect ecosystem composition, structure and functioning. 2) studies on how ecosystems respond to and recover from extreme weather events across past, present, and future climates are of interest. 3) Implications of extreme weather impacts on ecosystems for biodiversity and ecosystem service provision. We welcome a diverse array of contributions, including theoretical analyses, modeling approaches, field studies, experimental designs, and remote sensing analysis.

Key topics include:
- Ecosystem (terrestrial, coastal or marine) responses to extreme weather
- Role of extreme weather in shaping ecosystem composition, biodiversity, structure and functioning
- Vulnerability assessments of ecosystems
- Natural hazard risk to ecosystems in past, present and future climates
- Changes in ecosystems service provisions due to extreme weather events
- Resilience and recovery dynamics
- Impact and efficacy of Nature-Based Solutions (NBS) under extreme conditions, risk of maladaptation or disservices
- Regime shift / tipping points in ecosystems due to extreme weather events
- Extreme weather disturbance regimes affecting ecosystems across time
- Identification of extreme weather risk hotspots
- Interactions of natural hazard and anthropogenic disturbances to ecosystems

Solicited authors:
Ana Bastos
Convener: Chahan M. Kropf | Co-conveners: Carmen B. Steinmann, Sarah HülsenECSECS, Jeff Price
ITS3.7/BG0.6 EDI

The session aims to explore the intricate relationships between living organisms and the Earth system from different angles. It highlights research on the influence of biodiversity, and animals, on ecosystem functioning and resilience. While biological diversity is vital for natural ecosystems such as forests and wetlands, and crucial for maintaining healthy freshwater ecosystems, soil systems, and oceans, it is also a factor that affects an ecosystem’s response to disturbances, in turn affecting notions such as (ecosystem) integrity, health and resilience. Animals, on the other hand, are an integral part of the biosphere within the Earth system, and a growing body of evidence suggests that, despite their small biomass compared to plants and microbes, the animals in terrestrial and aquatic biomes are important geoengineers of both the physical and chemical environment.
Adopting an interdisciplinary approach, the session invites contributions from fields such as geosciences, ecology and modelling, recognizing the interplay between biological and physical processes in controlling key planetary processes such as water, carbon and nutrient cycling, as well as geomorphic processes. This comprehensive, broader approach helps highlight several distant topics, such as: how biodiversity affects ecosystem integrity, health, and response to disturbances; how it influences processes such as restoration, and rewilding, including reintroduction of large animals to restore ecosystem functioning. The session also focuses on the specific contributions of animals to Earth system processes, as the emerging discipline of zoogeoscience including biogeochemical cycles and physical displacement of soils and sediments and bioturbation. Finally, the session also addresses and it underscores the importance of scientific evidence in informing political decisions, such as the EU Nature Restoration Law.
In sum, in this session we aim to recognize the wide range of biogeoscience, and the broader Earth system science research projects with an aim to understand the functional role of biodiversity in the Earth system, and highlight the need for interdisciplinary research and the importance of studying these processes at various spatial and temporal scales. This session is combined from sessions ITS3.7/BG0.6 Biodiversity from a Geoscience perspective and BG1.9 Animals in the Earth System.

Convener: Bikem EkberzadeECSECS | Co-conveners: Jesper Christiansen, A. Rita Carrasco, Jeppe Aagaard KristensenECSECS, Annegret Larsen, Felicia Olufunmilayo Akinyemi
ITS3.12/BG0.8 EDI

Global change drivers on ecosystems, such as land/sea use change, direct exploitation, climate change, pollution, and invasive alien species are the major contributors to the accelerating biodiversity crisis and shifts in biome boundaries. Mounting evidence has demonstrated the link between these drivers and changes in biodiversity, such as the loss of species, declines in functional and genetic diversity, and reduction in geodiversity. However, our understanding of the impacts of these drivers on biodiversity across local to global scales remains limited. In this session, we warmly invite contributions related but not limited to studies on 1) the current state or patterns of biodiversity and main drivers; 2) changes in biodiversity and ecosystem functioning; 3) trends and future scenarios of biodiversity change; 4) species migrations and links to environmental and anthropogenic influences, and 5) changes in biodiversity resulting from conservation, restoration, management and policy.

We aim to bring together excellent research about past, present, and future biodiversity, using data from field sampling, and airborne or space-based remote sensing observations. We welcome studies ranging from local-scale field experiments to large-scale theoretical modeling, including both individual-ecosystem (i.e. terrestrial, marine and freshwater systems) and cross-ecosystem studies. We explicitly welcome novel conceptual ideas, large-scale observations, field experiments, earth system modeling, or data synthesis related to biodiversity change across spatial and temporal scales, and from various data sources toward a better understanding of global change impacts on biodiversity.

BG3.20 Borealization of tundra ecosystems

Arctic and alpine tundra ecosystems are changing fast in response to ongoing climate change and increased human pressures linked to land use changes. One observed phenomenon in response to these changes is the northward and upward shift in the distribution of temperate or boreal species from southerly latitudes or lower elevations, a process known as borealization. Examples of tundra borealization include the encroachment of woody species, the spread of non-native species, and changes in the composition of plant, animal and microbial communities. Borealization also alters the trophic and functional structure of ecosystems, changes landscape structure and impacts ecosystem processes such as the strength of carbon sink and sources.

Solicited authors:
David Leclere
Convener: Daijun Liu | Co-conveners: Mariana VerdonenECSECS, Elias KoivistoECSECS, Heng ZhangECSECS, Nezha AcilECSECS, Isabelle HelfensteinECSECS

BG2 – Methods in Biogeosciences

Sub-Programme Group Scientific Officer: Lisa Wingate

BG2.1 EDI

This session is open to all contributions in biogeochemistry and ecology where stable isotope techniques are used as analytical tools, with foci both on stable isotopes of light elements (C, H, O, N, S, …) and new systems (clumped and metal isotopes). We welcome studies from both terrestrial and aquatic (including marine) environments as well as methodological, experimental and theoretical studies that introduce new approaches or techniques (including natural abundance work, labelling studies, modeling).
Results from the successful EGU sessions on the ‘Application of Stable Isotopes in Biogeosciences’ that took place earlier have been published in several special issues of Organic Geochemistry and Isotopes in Environmental & Health Studies.

Co-organized by GMPV1
Convener: Michael E. Böttcher | Co-conveners: Marc-Andre CormierECSECS, Marco Lehmann, Katja Rinne-Garmston, Kirstin Dähnke, Anne-Désirée SchmittECSECS, Gerd Gleixner
BG2.2 EDI

We welcome contributions involving the use of stable isotopes of light elements (C, H, O, N, S) or novel tracers (such as COS) in field and laboratory experiments, the latest instrument developments, as well as theoretical and modelling activities, which advance our understanding of biogeochemical and atmospheric processes. We are particularly interested in the latest findings and insights from research involving:

- Isotopologues of carbon dioxide (CO2), water (H2O), methane (CH4), carbon monoxide (CO), oxygen (O2), carbonyl sulfide (COS), and nitrous oxide (N2O)

- Novel tracers and biological analogues

- Polyisotopocules including "clumped isotopes"

- Non-mass-dependent isotopic fractionation and related isotope anomalies

- Intramolecular stable isotope distributions ("isotopomer abundances")

- Quantification of isotope effects

- Analytical, methodological, and modelling developments

- Flux measurements

Co-organized by AS5
Convener: Getachew AdnewECSECS | Co-conveners: Jan Kaiser, Nerea UbiernaECSECS, Eliza Harris, Penelope PickersECSECS, Tim Arnold, Rona Thompson
BG2.4 EDI

Lipid biomarkers are valuable tools for reconstructing a variety of environmental processes in modern and (geological) past settings. Application of lipid biomarkers includes analyzing the distribution and stable isotopic composition of core lipids (e.g., n-alkanes, fatty acids, alkenones, sterols, hopanoids, HBIs, HGs, and GDGTs) and intact polar lipids in the environment. Given complex relationships between biogenic organic compounds and environmental conditions, it is crucial to understand the mechanisms that influence their molecular distribution and isotopic composition in diverse depositional environments. This includes identifying biogenic sources, physiological effects, evidence of transport, post-depositional processes, and diagenesis.
We seek studies that develop new lipid biomarkers and methods for applying biomarkers to modern settings and the geologic past in order to reconstruct environmental parameters such as temperature, precipitation, biogeochemical cycles, anthropogenic activities, and vegetation. These can be studies on the biosynthesis and phylogeny of source organisms, transport and diagenesis, calibrations to environmental parameters, proxy interpretation and applications to reconstruct past environmental conditions.

Solicited authors:
Francien Peterse
Convener: Jingjing GuoECSECS | Co-conveners: Nora Richter, Pablo Martínez-SosaECSECS, Petter HällbergECSECS, Addison RiceECSECS
BG2.6 EDI

The interplay between natural organic matter (NOM) including organic contaminants and decomposer communities at the nexus of solids, solutes and volatiles regulates a C reservoir larger than all living biomass on Earth, making it a keystone in the global carbon cycle. Despite its ubiquitousness, NOM remains a black box due to its astonishing molecular complexity. Advances in ultrahigh resolution mass spectrometry (FT-ICR-MS, Orbitrap, TOF-MS) have enabled researchers to analyze NOM and contaminants in all forms - solid, soluble and volatile - on the molecular-level. Ultimately, this allows to resolve the molecular complexity of NOM, and to elucidate its mediating role in various processes essential for life on Earth, such as energy flow, nutrient retention and resupply, or climate stability.

The challenge ahead of us is to synthesize the gained knowledge from various research communities (biogeochemistry, soil sciences, atmospheric sciences, aquatic sciences, analytical chemistry, geomicrobiology), ultimately providing useful data and process understanding to integrate in C cycle models that represent its molecular complexity in a more realistic way. To achieve this, it is also required to develop computational methods to align FT-ICR-MS data with complementary spectroscopic and mass spectrometric techniques (NMR, FT-IR, XPS, py-GC-MS, EEMs-PARAFAC, PTR-MS, etc.) and allow for a community-driven effort to share, curate and compare global molecular-level datasets.

In this session we therefore welcome proceedings in the following domains:
- Experimental, e.g. focusing on single or combined processes of natural and anthropogenic organic matter biogeochemistry or its links with other drivers such as microbial communities,
- Field-scale, e.g. studying the behavior of NOM across environmental gradients or interfaces,
- Modeling and simulation, e.g. integrating molecular-level data to improve the prediction of environmental processes or simulate ecosystem functioning,
- Computational, e.g. bioinformatic approaches to facilitate the analysis of molecular-level NOM data, or allowing its integration with complementary data streams,
- Analytical, e.g. improving or expanding the measurement of NOM on the molecular level, or providing novel tools to reveal its properties, responses or effects

We are looking forward to bringing together researchers from a wide range of disciplines to share their perspectives on studying NOM at EGU25!

Co-organized by OS3/SSS5
Convener: Carsten SimonECSECS | Co-conveners: Hannelore Waska, Hongyan Bao, Christos Panagiotopoulos, Marios Drosos, Gonzalo Gomez Saez, Sinikka Lennartz
HS10.11 EDI

The increased attention of society to climate change, drought and flood early warning systems, ecosystem monitoring and biodiversity conservation has led to a large demand for estimating, modelling, mapping, and forecasting evapotranspiration (ET) as a key water flux at the soil-vegetation-atmosphere interface. Cutting-edge techniques such as artificial intelligence (AI), data fusion, sharpening algorithms, and the integration of physical- and process-based models with empirical/statistical methods and machine learning are essential for bridging different scales while addressing and communicating method-specific uncertainties.

This session will focus on various ET estimation methods, including sap flow or soil heat pulse sensors, lysimeters, eddy covariance stations, scintillometers, and remote sensing. We will also explore new techniques like AI, data fusion, sharpening algorithms, machine learning, and cloud computing. Additionally, we will cover detailed evaluations of scale dependencies, strategies to handle uncertainties, systematic biases, and the representativity of estimates.

We welcome contributions that (1) assess and compare various in-situ and remote sensing methods, (2) analyse trends and spatio-temporal patterns in ET data, including error sources and uncertainty, (3) bridge scales between different in-situ measurements, modelled and remotely sensed ET, including validation and calibration challenges, (4) evaluate challenges and opportunities of applying AI methods, cloud computing and new technologies.

Solicited authors:
Jacob Nelson
Co-organized by BG2
Convener: Sibylle K. Hassler | Co-conveners: Neda AbbasiECSECS, Ana AndreuECSECS, Jannis GrohECSECS, Pamela Nagler, Hamideh Nouri, Corinna Rebmann
CL4.3 EDI

Stable and radiogenic isotopic records have been successfully used for investigating various terrestrial and marine sequences, fossils, evaporative rocks, palaeosols, lacustrine, loess, caves, peatlands. In this session we are looking for contributions using isotopes along with sedimentological, biological, paleontological, mineralogical, chemical records in order to unravel past and present climate and environmental changes or as tracers for determining the source of phases involved. Novel directions using triple isotopes, clumped isotopes, biomarkers are welcomed.
The session invites contributions presenting an applied as well as a theoretical approach. We welcome papers related to reconstructions (at various time and space scales), fractionation factors, measurement methods, proxy calibration, and verification.

INTIMATE (INTegrating Ice core, Marine and TErrestrial records) is a large, diverse, international scientific network interested in better understanding abrupt and extreme climate changes in the Northern Hemisphere during the Quaternary. INTIMATE’s fundamental approach is the synchronisation and comparison of high resolution palaeoclimate and environmental records based on their independent timescales.

Including Milutin Milanković Medal Lecture
Co-organized by BG2/SSP1
Convener: Ana-Voica Bojar | Co-conveners: Celia Martin-Puertas, Christophe Lecuyer, Octavian G. Duliu, Andrzej PelcECSECS, Michael E. Böttcher, Rik Tjallingii
ERE6.2 EDI

While the need for global cooperation in the face of global trends is obvious, funding mechanisms for environmental research and monitoring are still largely organised on a national and regional basis. Despite declared intentions to improve cooperation and thematic coordination in the formulation of related research and infrastructure programmes, concrete cooperation is hampered by a lack of resources and time for consultation, even in the case of thematically appropriate calls. This affects not only collaborative projects but also the improvement of interoperability and, ultimately, the concerted development and sustainable operation of services. Initiatives such as the G8 Group of Senior Officials (GSO) with its Recommendations for Global Research Infrastructures (GRI) have not led to a structural improvement of the situation. Still, Environmental Research Infrastructures (ENVRIs), have become a key instrument in environmental science and science-driven environmental politics.
Contributions to this session should present successful examples, experienced constraints and derived recommendations for action. They might address the value chain from open standardised observations and experiments data via scientific analysis towards societal impact through actionable knowledge, but also refer to,basic ENVRI activities like access to long-term operated in-situ facilities. An Impact Lecture will introduce the Global Ecosystem Research Infrastructures Initiative, in which SAEON/South Africa, TERN/Australia, CERN/China, NEON/USA, ICOS/Europe and eLTER/Europe will present their work on harmonised data systems, training and development, and collaboration in the use case 'ecological drought'.

Solicited authors:
Radovan Krejci
Co-organized by BG2/GI6
Convener: Michael Mirtl | Co-conveners: Werner Leo Kutsch, Beryl Morris
SSS9.5 EDI

Agrogeophysics harnesses geophysical methods such as ground-penetrating radar, electrical imaging, seismic,... from hand-held over drone to satellite-borne, to characterize patterns or processes in the soil-plant continuum of interest for agronomic management. These methods help develop sustainable agricultural practices by providing minimally-invasive, spatially consistent, multi-scale, and temporally-resolved information of processes in agro- ecosystems that is inaccessible by traditional monitoring techniques. The aim of this session is to feature applications of geophysical methods in agricultural research and/or show methodologies to overcome their inherent limitations and challenges. We welcome contributions monitoring soil or plant properties and states revealing information relevant for agricultural management; studies developing and using proximal or remote sensing techniques for mapping or monitoring soil-water-plant interactions; work focused on bridging the scale gap between these multiple techniques; or work investigating pedophysical relationships to better understand laboratory-scale links between sensed properties and soil variables of interest. Submissions profiting on data fusion, utilizing innovative modeling tools for interpretation, and demonstrating novel acquisition or processing techniques are encouraged.

Solicited authors:
Dongxue Zhao,Valentin Michels
Co-organized by BG2
Convener: Alejandro Romero-RuizECSECS | Co-conveners: Guillaume BlanchyECSECS, Agnese InnocentiECSECS, Lena LärmECSECS
SSS5.5 EDI

The cycling of carbon (C) and key nutrients, such as nitrogen (N) and phosphorus (P), in soils is crucial for maintaining ecosystem health, agricultural productivity, and climate regulation. As global challenges, such as climate change, soil degradation, and nutrient imbalances intensify, there is a rising demand for advanced analytical methods that can unravel the complexities of these biogeochemical cycles.
The session aims to bring together experts from a broad range of disciplines, including soil science, biogeochemistry, analytical chemistry, and related fields, to discuss innovative analytical techniques that improve our understanding of C, N, and P cycling. We welcome discussions on the application of cutting-edge methods such as high-resolution spectroscopy, stable isotope techniques, molecular-level analyses, and other emerging approaches to address long-standing questions on the dynamics, interactions, and transformations of C, N, and P in diverse soil environments—from agricultural lands to natural ecosystems.
We invite contributions from researchers who are at the forefront of employing or developing these novel tools to decipher C, N, and P cycling in soil. This session will provide a platform for discussing the challenges, opportunities, and future directions in soil element cycling, fostering collaborations across disciplines.

Co-organized by BG2
Convener: Layla Márquez San EmeterioECSECS | Co-conveners: Vijayananda SarangiECSECS, Ye Tian, Wenyi XuECSECS, Marie Spohn

BG3 – Terrestrial Biogeosciences

Sub-Programme Group Scientific Officer: Robyn Pickering

BG3.1 EDI

The terrestrial vegetation carbon balance is controlled not just by photosynthesis, but by respiration, carbon allocation, turnover (comprising litterfall, background mortality and disturbances) and wider vegetation dynamics. Recently observed changes in vegetation structure and functioning are the result of these processes and their interactions with atmospheric carbon dioxide concentration, nutrient availability, climate, and human activities. The quantification and assessment of such changes has proven extremely challenging because of a lack of observations at spatio-temporal scales appropriate for evaluating trends and projecting them into the future.

This limited observation base gives rise to high uncertainty regarding the future terrestrial carbon sink. Many questions need answer to determine if it will be sustained under future environmental changes, or whether increases in autotrophic respiration or carbon turnover might counteract this negative feedback to climate change. For instance, will accelerated background tree mortality or more frequent and more severe disturbance events (e.g. drought, fire, insect outbreaks) turn vegetation into carbon sources? How will shifts in dynamics of plant mortality, establishment, and growth influence forest composition?

Uncertainties and/or data gaps in large-scale empirical products of vegetation dynamics, carbon fluxes and stocks may be overcome by extensive collections of field data and new satellite retrievals of forest biomass and other vegetation properties. Such novel datasets may be used to evaluate, develop and parametrize global vegetation models and hence to constrain present and future simulations of vegetation dynamics. Where no observations exist, exploratory modelling can investigate realistic responses and identify necessary measurements. We welcome contributions that make use of observational approaches, vegetation models, or model-data integration techniques to advance understanding of the effects of environmental change on vegetation dynamics, tree mortality as well as carbon stocks and fluxes at local, regional or global scales and/or over long periods.

Solicited authors:
Silvia Caldararu
Convener: Ana Bastos | Co-conveners: Matthias Forkel, Lucia Sophie LayritzECSECS, Thomas Pugh, Martin Thurner
BG3.2 EDI

Human activities on land (LULCC) shape climate by altering land-atmosphere fluxes of carbon, water, energy, and momentum. An increasing focus on land-based climate mitigation and adaptation strategies to meet more stringent targets has expanded the range of land management practices considered specifically for their potential to alter terrestrial carbon cycling or mediate favorable environmental conditions. This focus has also called attention to potential tradeoffs between climate-centric aspects of LULCC and its influences on biodiversity, hydrology and other environmental factors. Advancements in modeling and measurement techniques are opening new possibilities to better describe LULCC and its effects on the Earth system at multiple temporal and spatial scales.

This session welcomes all contributions aimed at furthering our understanding of LULCC in the Earth system, including those addressing LULCC effects on carbon, climate, hydrology, and/or biodiversity, and aims to present studies that can inform adoption of appropriate land-based strategies for climate mitigation, adaptation, and ecosystem restoration.

Solicited authors:
Karina Winkler
Co-organized by CL3.2
Convener: Alan Di Vittorio | Co-conveners: Ryan Bright, Gregory Duveiller, Thomas O'Halloran, Julia Pongratz
BG3.3 EDI

Plant traits extend the range of earth observations to the level of individual organisms, providing a link to ecosystem function and modelling in the context of rapid global changes. However, overcoming the differences in temporal and spatial scales between plant trait data and biogeochemical cycles remains challenging.

This session will address the role of plant traits, biodiversity, acclimation, and adaptation in the biogeochemical cycles of water, carbon, nitrogen, and phosphorus. We welcome conceptual, observational, experimental and modelling approaches and studies from the local to the global scale, including in-situ or remote sensing observations.

Solicited authors:
Iain Colin Prentice,Sandy Harrison
Convener: Jens Kattge | Co-conveners: Michael Bahn, Oskar Franklin, Julia JoswigECSECS
BG3.4 EDI | PICO

Although climate change is a natural process, it is significantly stimulated by anthropogenic activities. The acceleration of climate change is directly connected with ecological stability, soil degradation, and hydrological extremes, which are considered as the main consequences of climate change. As climate change intensifies, extreme and unexpected weather events are becoming more frequent.
The aim of this session is to highlight a broad range of research methods and results related to climate change. This interdisciplinary session should reflect, discuss, and share scientific knowledge on a local and regional scale with the aim to increase innovative knowledge on climate change and its impacts, ecosystem response and new techniques to prevent and reduce the negative consequences.

This session encourages contributions from several fields related to:
- climate change impacts (biodiversity loss, rising temperatures, hydrological extremes, soil degradation, ecosystem response to climate change);
- droughts and floods; precipitation deficiency or extreme precipitation with solutions aimed at reducing the negative impacts;
- ecological stability and climate change; changes of ecological stability, deforestation, human interactions with the environment and evaluation of restoration success;
- green cities to increase the ecological stability of the urban landscape;
- techniques and methods to prevent and reduce the negative impacts of climate change (such as soil degradation, carbon sequestration, changes in natural, agricultural, and forest ecosystems, reduction of overall ecological stability and character of the landscape);
In addition, attention will be given to the sustainability of management practices, the importance of appropriate land use management as the main tool for preventing the degradation processes, the distribution and vitality of ecosystems, and improving the condition of forest ecosystems in order to increase the overall character of the landscape.

Convener: Adrienn HorváthECSECS | Co-conveners: Borbála SzélesECSECS, Silvia Kohnová, Péter Kalicz
BG3.5 EDI

Human activities are altering a range of environmental conditions, including atmospheric CO2 concentration, climate, and nutrient inputs. Understanding and predicting their combined impacts on biogeochemical cycles, ecosystem structure and functioning is a major challenge. Divergent future projections of terrestrial ecosystem models reveal uncertainties about fundamental processes and missing observational constraints. Models are routinely tested and calibrated against data from ecosystem flux measurements, remote sensing, atmospheric inversions and ecosystem inventories. However, it remains challenging to use available observations to constrain process representations and parameterizations in models simulating the response of ecophysiological, biogeochemical, and hydrological processes to environmental changes.

This session focuses on the influence of CO2, temperature, water stress, and nutrients on ecosystem functioning and structure. A focus is set on learning from manipulative experiments and novel uses of continuous ecosystem monitoring and Earth observation data for informing theory and ecosystem models. Contributions may cover a range of scales and scopes, including plant ecophysiology, soil organic matter dynamics, soil microbial activity, nutrient cycling, plant-soil interactions, or ecosystem dynamics.

Convener: Kevin Van SundertECSECS | Co-conveners: Karin Rebel, Benjamin Stocker, Teresa Gimeno, Sönke Zaehle