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SSS – Soil System Sciences

Programme Group Chairs: Heike Knicker, Dan Evans

SSS0.1

Healthy soils underpin food production, climate resilience and wider ecosystem functioning, yet more than 60% of European soils are considered degraded. The period around 2027 brings two important opportunities to reshape the relationship between soil science, policy and practice. First, the forthcoming reform of the Common Agricultural Policy (CAP) for the post-2027 period creates an opportunity to strengthen incentives for sustainable soil management. Second, the EU Mission Soil will be moving from experimentation towards the wider implementation and upscaling of Living Labs, accelerating the co-production and application of knowledge on sustainable soil management.

Realising the potential of these initiatives will depend on much more than generating new scientific evidence. Effective soil stewardship requires sustained exchange between scientists, policymakers, farmers, advisers and the wider agri-food sector. Yet these relationships are often fragmented by differences in language, priorities, evidence, experience and perceptions of what constitutes credible knowledge.

This session will examine how knowledge about soils is produced, interpreted, exchanged and acted upon across this diverse community. It will explore how soil scientists can better understand the knowledge needs, perspectives and decision-making contexts of different stakeholders, while recognising farmers, practitioners and policymakers as producers of knowledge in their own right.

We invite participants from across the knowledge chain to come together to ask a deceptively simple question: how do we know what we know? Through dialogue across disciplines and sectors, the session aims to identify practical ways to strengthen bidirectional knowledge exchange and build a more collaborative pathway towards sustainable European soils.

Convener: Dan Evans | Co-conveners: Franklin HarrisECSECS, Guusje KoorneefECSECS

SSS2 – Soil Erosion and Conservation

Sub-Programme Group Scientific Officers: Milica Kasanin-Grubin, Gema Guzmán, Belén Cárceles

SSS2.1 | PICO

Soil erosion has been traditionally divided into sheet, rill, and gully erosion. Rills and gullies concentrate overland flow, leading to a significantly increased flow erosivity. These forms of concentrated flow erosion, both above and below ground, represent an important sediment source within watersheds and produce sizeable economic losses (e.g. reduced crop yields, reservoir sedimentation). Moreover, rills and gullies are effective links for transferring runoff, sediment and pollutants. Despite their relevance, the physical mechanisms that constitute concentrated flow erosion remain poorly understood.
This session aims to address this research gap and will focus on recent studies aiming to better understand the process of rill and gully erosion, with the ultimate aim of developing predictive tools and effective management strategies. As such we welcome contributions on: monitoring and measurement techniques; the factors and processes controlling rill, piping and gully erosion; modelling approaches; restoration and control; and the role of piping, rills and gullies in hydrological and sediment connectivity.

Convener: Iñigo BarberenaECSECS | Co-conveners: Javier Casalí, Belén Cárceles, Donghong Xiong, Chunmei Wang
SSS2.2 EDI

Soil erosion is a major threat to the global soil functions that sustain life on land, and substantial research has been devoted to understanding, predicting, and controlling erosion processes. Yet there appears to be a discrepancy between the (perceived) gravity of soil erosion and recent scientific activity in the field. Models have become the primary epistemic tool in erosion science, despite a continued overreliance on 1960s empirics now masked by computational prowess. Meanwhile, we struggle to measure lateral soil fluxes beyond small plots, and implementing erosion control measures remains a major societal challenge. These issues point towards a reliability crisis that, left unchecked, risks eroding the credibility of the research field.
In this session, we want to co-create future(s) for erosion science by rethinking where we want to go as a scientific field and how we get there through the choices we make today. As such, we welcome a wide range of contributions, from critical perspectives to applied research. We invite submissions addressing, but not limited to, the following subjects:
- New or improved approaches to measuring and modelling soil erosion;
- Impacts of erosion on soil health, soil functions and ecosystem services;
- Interactions between climate change, land-use change, and soil change in shaping soil erosion and its dynamics;
- Evidence-based soil conservation—particularly approaches that integrate soil conservation into broader landscape management perspective;
- Translating (uncertain) modelled erosion rates into risk assessments for policymakers and managers;
- New or improved methods for calibrating and testing soil erosion models—particularly approaches that increase model falsifiability and/or that report case studies of model invalidation (if you have “bad” results, we want to hear about it!)
- We expressly encourage contributions that provide broader, critical perspectives on soil-erosion research and point towards a direction forward.

Solicited authors:
Gerard Govers
Convener: Pedro BatistaECSECS | Co-conveners: Olivier Cerdan, Anette Eltner, Peter Fiener, Yanru Wen

SSS3 – Soil as Records in Time and Space

Sub-Programme Group Scientific Officers: Lilit Pogosyan, Guido Stefano Mariani, Daisy Valera Fernandez

SSS3.1 EDI | PICO

Micromorphology is an irreplaceable tool that provides access to multiple characteristics of soils and sediments to deepen our knowledge on both long- and short-term soil and landscape dynamics in time. W. Kubiëna, who introduced the method of micromorphological analysis, stated that “a crushed or pulverized soil is related to the soil formed by nature like a pile of debris to a demolished building”. In fact, the micromorphological analysis of undisturbed samples is fundamental for a holistic architectural approach to the study of soil genesis and soil functions, and recently it is increasingly advocated as an advanced framework in studies of soil genesis, behavior and functions. Moreover, this method uniquely enables the detection of faint traces of initial and/or weakly developed soil processes and the direct reconstruction of sequences of both natural and anthropogenic soil and sedimentary processes over time.
After more than 80 years of method’s application it retained its key role in studies of soils diversity, soil genesis and behavior in space and time, but also has advanced to new methodological and technological frontiers. During last decades, micromorphology evolved from a primarily descriptive method into an increasingly quantitative technique, allowing wider application, shorter analysis time and higher replicability. Possibilities of working with stored digital images without access to a microscope further increases the accessibility of micromorphological analysis, while collections of thin sections preserve records of sites and samples that may no longer be accessible.
The session is open to but not limited to contributions on the application of micromorphological analysis as one of the proxies for paleoenvironmental reconstructions in soil-sedimentary archives, studies of soil genesis, and, most importantly, as a tool to identify and understand human impacts in modern and archeological contexts. We particularly welcome contributions highlighting methodological innovations in micromorphology.

Convener: Lilit PogosyanECSECS | Co-conveners: Guido Stefano Mariani, Maria Bronnikova, Daisy Valera FernandezECSECS, Christopher BaishECSECS
SSS3.2 | PICO

Pedology provides a framework for understanding the formation, distribution, and evolution of soils within landscapes. Sitting at the intersection of the geosphere, hydrosphere, cryosphere, and atmosphere, soils and the landscapes within which they reside represent useful proxy records for understanding the complementary influences of time, topography, biota, climate, and mineralogy on the evolution of planetary surfaces. This session brings together research exploring soil–landscape relationships across spatial and temporal scales, from individual pedons to regional landscapes and across a diversity of environmental settings, including modern, past, extreme, and extraterrestrial environments. We welcome contributions focused on soil genesis, soil geomorphology, paleopedology, soil mapping, and astropedology that address questions related to soil and landscape evolution, paleoenvironmental reconstruction, and related phenomena. The session aims to highlight novel and diverse approaches for using soils to understand environmental change and the history of terrestrial and planetary surfaces.

Convener: Christopher BaishECSECS | Co-conveners: Anthony Feldman, Barret Wessel, Rok Turniški
GM4.3 EDI | PICO

Human activity became a major player of global climatic and environmental change in the course of the late Quaternary, during the Anthropocene. Consequently, it is crucial to understand these changes through the study of former human-environmental interactions at different spatial and temporal scales. Documenting the diversity of human responses and adaptations to climate, landscapes, ecosystems, natural disasters and the changing natural resources availability in different regions of our planet, provides valuable opportunities to learn from the past. To do so, cross-disciplinary studies in Geoarchaeology offer a chance to better understand the archaeological records and landscapes in context of human culture and the hydroclimate-environment nexus over time. This session seeks related interdisciplinary papers and specific geoarchaeological case-studies that deploy various approaches and tools to address the reconstruction of former human-environmental interactions from the Palaeolithic period through the modern. Topics related to records of the Anthropocene from Earth and archaeological science perspectives are welcome. Furthermore, contributions may include (but are not limited to) insights about how people have coped with environmental disasters or abrupt changes in the past; defining sustainability thresholds for farming or resource exploitation; distinguishing the baseline natural and human contributions to environmental changes. Ultimately, we would like to understand how strategies of human resilience and innovation can inform our modern policies for addressing the challenges of the emerging Anthropocene, a time frame dominated by human modulation of surface geomorphological processes and hydroclimate.

Co-organized by SSS3
Convener: Guido Stefano Mariani | Co-conveners: Julia Meister, Mirijam ZickelECSECS, Kathleen Nicoll, Hans von Suchodoletz
GM6.2 EDI | PICO

Currently arid to sub-humid regions are home to >40% of the world’s population, and many prehistoric and historic cultures developed in these regions. Due to the high sensitivity of drylands to also small-scale environmental changes and anthropogenic activities, ongoing geomorphological processes under the intensified climatic and human pressure of the Anthropocene, but also the Late Quaternary geomorphological and paleoenvironmental evolution as recorded in sediment archives, are becoming increasingly relevant for geological, geomorphological, paleoenvironmental, paleoclimatic and geoarchaeological research. Dryland research is constantly boosted by methodological advances, and especially by emerging linkages with other climatic and geomorphic systems that allow using dryland areas as indicator-regions of global environmental changes.
This session aims to pool contributions dealing with past to recent geomorphological processes and environmental changes spanning the entire Quaternary until today, as well as with all types of sedimentary and morphological archives in dryland areas (dunes, loess, slope deposits, fluvial sediments, alluvial fans, lake and playa sediments, desert pavements, soils, palaeosols etc.) studied on different spatial and temporal scales. Besides case studies on archives and landscapes from individual regions and review studies, cross-disciplinary, methodical and conceptual contributions are especially welcome in this session, e.g., dealing with the special role of aeolian, fluvial, gravitational and biological processes in dryland environments and their preservation in deposits and landforms, the role of such processes for past and present societies, methods to obtain chronological frameworks and process rates, and emerging geo-technologies.

Co-organized by HS13/SSS3
Convener: Hans von Suchodoletz | Co-conveners: Janek WalkECSECS, Joel Roskin, Abi Stone, Markus Fuchs

SSS4 – Soil Biology, Microbiology and Biodiversity

Sub-Programme Group Scientific Officers: Lucia Fuchslueger, Nataliya Bilyera, Kyle Mason-Jones

SSS4.1

Soil health is the capacity of soil to function as an ecosystem, providing means to sustain productivity and maintain environmental quality. In the EU alone, 60% of the soils are degraded due to both global change factors (warming, extreme weather events, elevated CO2 levels, droughts, floods, etc.) and human activity (intensive agriculture, land-use change, industrial processes, etc.). Initial modifications of the physical and chemical soil properties, can have dramatic effects on soil biota, which is an important driver of ecosystem services.
We invite contributions from field, laboratory and modeling studies focused on biological soil health descriptors or indicators, such as microbial respiration, enzyme activities, diversity and functions of soil (micro)organisms and other parameters affected by global change and human activities. This session welcomes contributions on soil health assessment methods, with a focus on biological soil fertility and the ecosystem services provided by soils. We particularly encourage abstracts that explore soil health across temporal and spatial scales, from micro-level to global perspectives.

Convener: Nataliya BilyeraECSECS | Co-conveners: Emmanuel Arthur, Yakov Kuzyakov
SSS4.2

Soil biodiversity is increasingly recognized as a key component of soil health, yet current assessment frameworks often focus on a limited range of biological groups or isolated ecosystem functions. While these specific groups can provide valuable indicators of soil conditions, they may not fully capture the complexity of soil processes and multitrophic interactions that underpin ecosystem functioning. Integrating microorganisms, soil fauna, and their interactions across trophic levels into robust and operational soil health indicators remains a major scientific and practical challenge.
This session aims to promote a holistic perspective on soil health indicators derived from soil biodiversity across different trophic groups and methodological approaches. We encourage contributions exploring how information from individual soil organisms groups or integrative multi-trophic approaches can improve indicators related to key soil processes such as carbon and nutrient cycling, soil structure formation, and ecosystem stability under environmental change. Particular attention will be given to studies testing existing or novel biodiversity-based indicators and their applicability across different environmental contexts.
The session invites interdisciplinary experimental, observational, and modelling approaches across scales, with particular interest in studies that bridge soil biodiversity research with development and application of soil health monitoring frameworks, implementation of operational indicators in restoration practices, nature-based solutions, and environmental policy. Contributions from researchers working on specific organismal groups are equally welcome, provided they connect to broader multi-trophic or integrative frameworks.

Convener: Virginia Sánchez-Navarro | Co-conveners: Natalia Rodríguez, Stefan Geisen
SSS4.3 EDI

Sustainable agricultural practices are sought to be implemented across Europe and worldwide to improve soil nutrient cycling processes which includes nitrogen (N) and phosphorus (P) and to reduce loss of nutrients through leaching, surface runoff and gaseous emissions. Indeed, EU targets have been set to improve nutrient use efficiencies (NUE) by 50% by 2030. A key aspect in achieving such a goal is to improve soil carbon (C) stocks and soil organic matter (SOM). It is assumed that by reversing the widespread loss of soil C in Europe’s soils, nutrient-use efficiencies may be improved through the betterment of soil multi-functionality. Soil microbiota will play key role in sustainable plant nutrient supply as they are key drivers in making soil nutrients N and P plant available, while at the same time immobilise excess N and P that is at risk of loss to ground- and surface-waters. Increasing soil C stocks sustainably can be achieved by including organic materials of waste origin from the circular economy model. This will reduce linear economy dependencies and engage the circular economy for the sustainable supply of not only C, but also vital plant nutrients N and P. This session aims to advance our limited understanding of the relationships between soil C and the microbial activities in soil that decide whether plant nutrients N and P are made available or are immobilized. Optimization these processes would allow to improve NUE by more targeted supply of plant nutrients through microbial activities, while at the same time excess nutrients can be prevented from leaching into the ground water by microbial immobilization. The use of circular economy fertilizers with substantial C content may provide multiple benefits by reducing the need for non-renewable linear economy fertilizers while at the same time promote microbial driven NUE. Further research in soil stoichiometry, microbial driven NUE and circular economy fertilization is needed to make the gains in sustainable agriculture that is needed in Europe and the rest of the world.

Convener: Achim Schmalenberger | Co-conveners: Aaron Fox, Gary Bending, Jianqing Tian, Stefanie Schulz
SSS4.4

Microbial metabolism is the engine of key soil functions, including nutrient cycling, carbon transformation, and plant growth promotion. Their metabolism and growth rely on C and energy as well as nutrients (e.g., N and P) and electron acceptors (O2, NO3, etc. ... or C itself). Microbial death processes close the loop to return biomass to non-living soil organic matter as necromass, changing its original quality. This coupled, dynamic system can be investigated at different scales (nm to km) and from diverse perspectives, leveraging concepts of carbon use efficiency (CUE), microbial ecophysiology, thermodynamics, and ecological stoichiometry. This session integrates experimental and modelling insights to elucidate how soil microbial metabolism drive energy and matter flows, taking account of their interactions with other organisms, dependency on environmental conditions, and the implications for soil functions.

We welcome new insights into soil microbial metabolism, growth and death, across the diverse transformations and interactions that these involve. Topics of interest include cutting-edge characterization of microbial activity and turnover (e.g., isotope tracing, calorimetry, metagenomics), microbial ecophysiology and stoichiometry, physiological responses to (micro)environmental changes (e.g. metabolomics), carbon and energy-use efficiency, alongside approaches to understand microbial functional responses (e.g. dynamic modelling, artificial intelligence). We aim to stimulate interdisciplinary discussions to advance our understanding of soil biology at scales from the mechanistic understanding of biogeochemical processes to global change.

We are excited to welcome Christina Kaiser as our invited speaker in 2027.

Convener: Kyle Mason-Jones | Co-conveners: Katerina Georgiou, Sergey Blagodatsky
SSS4.5

Global change—including climate warming, altered precipitation, land-use intensification, and changing nutrient inputs—is reshaping ecosystems worldwide, with profound consequences for soil carbon and nutrient cycling. Microbial communities are the key engines of these cycles, ultimately determining whether soils act as sinks or sources. Building a better understanding of how microbial communities, activity and physiology respond to diverse aspects of Global change is crucial to predict biogeochemical processes across temporal and spatial scales.

This session highlights research that integrates microbial physiology and diversity into our understanding of soil biogeochemistry under global change. Contributions range from controlled studies with microbial isolates to ecosystem-level assessments across diverse climates, employing flux quantification techniques and advanced approaches such as omics, isotope tracing, microscopy, and spectroscopy. We feature empirical and theoretical studies addressing soil microbial resistance, resilience, and adaptation to single and multi-factorial climatic disturbances, as well as research on the interactions between soil microorganisms, plants and fauna. Join us to exchange ideas, share new findings, and discuss how linking soil microbes to ecosystem processes can improve our predictions of ecological responses in a rapidly changing world.

Convener: Albert C. Brangarí | Co-conveners: Lettice Hicks, Lucia Fuchslueger, Alberto Canarini
SSS4.6

Soil, as a highly heterogeneous environment, comprises a myriad of microhabitats hosting an unparalleled biodiversity, ranging from microbiota to plant roots. Several physical and chemical parameters define the soil microhabitat: the geometry of the pore space, notably its connectivity, the water distribution at the microscale and the nature, distribution and association of organic compounds within the soil mineral matrix (organo-mineral associations, soil aggregates). Variations in these parameters result in micro-gradients in oxygen, moisture, nutrients and organic compounds, acting as ecological filters for soil biota, usually promoting the co-existence of contrasting ecological strategies. In addition, the soil microhabitat exerts significant constraints on the mobility of the soil biota, with major consequences for the interactions between soil organisms and repercussions on soil functioning. Finally, microhabitats are highly variable in time, being constantly re-modelled by numerous factors such as the alternation of wet and dry cycles, the activity of the soil biota, especially plant roots and ecosystem engineers and the input of fresh organic matter.
In this session we would like to invite contributions on: (i) deciphering the main drivers of the formation and spatiotemporal variability of the soil microhabitats, such as the release of EPS, the formation of biopores, etc., (ii) quantifying the role of the soil microhabitat in determining soil ecology, through field and experimental (microcosms, control of matric potential, isotopic tracing, etc.) approaches, (iii) describing the physico-chemical properties of the soil microhabitats, notably by developing novel tools (µCT, NanoSIMS, microscopy, etc.) rebuilding artificial microhabitats for experimental reproducible works (Soil chips, etc.). and (iv) modeling approaches that aims to capture soil functioning within the heterogeneous soil matrix. Finally, studies assessing the variability in soil activity within the soil matrix, notably focusing on microbial molecular analysis are also welcome.

Convener: Amandine Erktan
SSS4.7

Over the Earth’s history, microorganisms have evolved distinct ecological strategies to capture resources, grow, tolerate stress and interact with other micro- and macroorganisms. These so-called life-history strategies emerge from combinations of physiological traits that are shaped by local environmental conditions and biotic interactions. Viewing soil microbial communities from this angle is an opportunity to move beyond taxonomic patterns and broad classifications towards a deeper understanding of how functionally diverse taxa co-exist and, ultimately, how they influence ecosystem processes such as carbon and nitrogen cycling.
This session examines how microbial traits, functional groups and community assembly shape nutrient and biogeochemical cycling, ecosystem processes and resilience to natural and anthropogenic disturbance. Of particular interest are studies testing trait-based and life-history frameworks, identifying shifts in microbial strategies across environmental gradients or land-use changes. Contributions regarding individual microorganisms to complex communities, combining experimental, genomic or modelling approaches, are encouraged.

Convener: Damien Finn | Co-convener: Rebeca Leme OlivaECSECS
SSS4.8

Soil is the largest terrestrial pool of carbon. Consequently, soil organic carbon (SOC) and soil inorganic carbon (SIC) are the main indicators of soil health, fertility, and biodiversity.
Effective monitoring and modeling of SOC and SIC stocks are necessary to understand their dynamics and identify chances for sustainable management, and are crucial to define the soil health status, its dynamics and impact.
Modeling techniques of soil traits, and especially the stable C fraction, are thus essential for scaling up data and predicting future changes, but monitoring at spatiotemporal levels and on the soil profile in agroecosystem and natural system is still an important challenge.
Soil carbon storage and dynamics, and soil health can greatly be affected by land cover and management, including clear-cutting, soil sealing, and agricultural intensification, especially tillage, application of fertilisers and residues, use of active ingredients, and reduction of the diversification.
In addition, climate change, and especially the variation in temperature and precipitation patterns, can modify the dynamics of soil carbon, through a effect on soil moisture regime and microbial activity, with scarcely predictable effects on soil health and nutrient availability for crops, animals, and microbes.
Nutrient availability regulates C decomposition and stabilization, thereby tightly linking nutrient cycles with soil dynamics of C and other elements, with special emphasis to N. Tools such as isotopic tracers, lysimeter studies, and digital monitoring platforms provide new insights into nutrient fluxes and their interactions with soil carbon pools.
This session addresses the dynamics of SOC, SIC, and nutrients in agroecosystems, and definition and application of soil health, and investigates innovative monitoring and modelling strategies for optimizing soil carbon and nutrient management, and predict soil health depending on the management, and finally support decision-making in natural and agroecosystems. Contributions that integrate monitoring and modelling of nutrient–carbon interactions and that highlight their implications for sustainable soil management are particularly welcome

Convener: Sergio Saia | Co-conveners: Ahlem TliliECSECS, Viktoriia Hetmanenko, Calogero Schillaci, Giulia Bondi
SSS4.9

Microbial life in soil is highly heterogeneous in space and time. Microbial activity hotspots are localized in the rhizosphere, detritusphere, biopores, hyphosphere, and aggregate surfaces. Although these hotspots occupy only a fraction of the soil volume and may persist for limited periods, they dominate carbon and nutrient transformations and thereby exert a major influence on soil functioning.
This session aims to bring together studies focused on microbial life and biogeochemical processes in soil hotspots across spatial and temporal scales. We invite contributions addressing: (i) the formation, persistence, and turnover of microbial hotspots and the biotic and abiotic factors controlling them; (ii) microbial activity, interactions, community composition, and functional traits within hotspots; (iii) the contribution of hotspots to cycles of carbon, nitrogen, phosphorus, and other elements and to soil organic matter dynamics; (iv) responses of microbial hotspots to environmental change and disturbances; and (v) new experimental, imaging, molecular, isotopic, and modelling approaches for identifying hotspots, quantifying their activity, and linking microscale processes to soil- and ecosystem-scale functions.

Convener: Bahar S. Razavi | Co-conveners: Mehdi RashtbariECSECS, Diogo Neves Proença, Yakov Kuzyakov
SSS4.10

Biogeochemical activity in soil is concentrated in hotspots created by living roots, decomposing residues, fungal networks, soil fauna, biopores, aggregates and mineral surfaces. These domains are not fixed. They emerge, overlap, shift between oxic and anoxic states, and can persist after the original plant input has ceased. The central challenge is no longer only to locate hotspots. We also need to explain how they develop, what triggers functional shifts, and when brief hot moments leave lasting effects on soils and plants.

This session focuses on feedbacks among plant inputs, microbial physiology and succession, and the physical and chemical soil environment. We welcome experimental and modelling studies of the rhizosphere, detritusphere, biopores, aggregates and other soil microhabitats, including links among them.

How do root exudates, litter and microbial residues regulate carbon and nutrient flows?

How do soil structure, water, oxygen and redox cycles control microbial growth, enzyme activity, priming and greenhouse-gas formation?

How do plant development and root death, day–night cycles, wetting and drying, climate extremes, pollution and management reshape hotspot resistance, recovery and legacy effects?

We particularly encourage spatially and temporally resolved work using enzyme and chemical imaging, microsensors, isotope tracing, tomography, microfluidics, single-cell methods, metabolomics, multi-omics or synthetic communities. Process-based and data-driven models that connect hotspot dynamics with root systems, soil profiles, fields and ecosystems are equally welcome. Contributions from agricultural, forest, grassland, wetland and restored soils are invited. Together, these contributions will help explain when short-lived, local interactions lead to persistent changes in carbon storage, nutrient availability, soil structure, greenhouse-gas emissions, plant health and ecosystem resilience.

Convener: Shang WangECSECS | Co-convener: Evgenia Blagodatskaya
SSS4.11

Soil microorganisms allocate carbon (C) and energy not only to growth but also to maintenance and other non-growth processes, including cellular repair and stress tolerance, dormancy, storage, and the production of extracellular enzymes and polymeric substances. How microorganisms partition resources among these growth and non-growth pathways determines whether C is respired, released to the extracellular environment, or retained in biomass, with consequences for necromass formation and the persistence of soil organic matter. Yet, the energetic costs and trade-offs underlying this partitioning remain poorly quantified and are not fully reflected in common metrics like the microbial carbon use efficiency (CUE). Thermodynamic approaches offer a complementary mechanistic framework, with the potential to constrain and predict metabolic responses even in complex systems where individual processes cannot be fully resolved.
This session explores microbial C and energy allocation as a mechanistic link between microbial physiology and soil C persistence, from single cells to the ecosystem scale. We welcome experimental, theoretical and modelling contributions on microbial maintenance and non-growth metabolism, carbon and energy use efficiency, microbial responses to environmental change (e.g., warming, drought, land-use change), and implications for C stabilization. We particularly encourage studies applying or combining methods to quantify microbial C and energy use, such as isotope tracing, calorespirometry, thermodynamic approaches, and process-based modelling. By connecting microbial ecology and physiology with soil biogeochemistry, we aim to advance a bioenergetic understanding of how microbial metabolism regulates the fate of soil C and to explore how thermodynamic constraints can improve the mechanistic basis of predictive models.

Convener: Rebeca Leme OlivaECSECS | Co-conveners: Martin-Georg EndressECSECS, Thomas Maskow
SSS4.12

The contribution of soil organisms to ecosystem service provision remains poorly quantified. Indeed, soil fauna shape soil hydrology and biogeochemical cycling through bioturbation, pore formation, faeces production, vertical redistribution of organic matter and mucus secretion. While providing ecosystem services, such as erosion control, nutrient cycling and carbon sequestration, their activity can also generate disservices, for example by stimulating greenhouse gas emissions.
This session aims to bring together researchers investigating how the functional diversity of soil macro- and meso-fauna shapes soil processes and ecosystem services across scales, from individual species at microscale to communities at ecosystem scale. We particularly encourage contributions that use of measurable functional traits and bioturbation activities to quantify faunal effects on soil functioning. We invite studies addressing how soil fauna by pore formation, faeces production and vertical mixing influences soil organic carbon storage, water infiltration and retention, nutrient cycling and other ecosystem functions.
Moreover, the session will address the challenge of scaling faunal effects from controlled experiments to field conditions. We welcome approaches combining community composition, functional diversity, bioturbation measurements and soil properties with observations of ecosystem services across contrasting environments. Studies from both temperate and tropical systems are welcome to explore how environmental context modifies the relationships between soil fauna activity and ecosystem service provision.
We also invite contributions addressing the representation of faunal activity in soil carbon and water dynamic models, the development of indicators of fauna-mediated ecosystem functioning, or the quantitative and spatial assessment of ecosystem services provided by soil fauna.
By bringing together soil ecologists, biogeochemists, soil physicists, modellers and ecosystem-service researchers, the session seeks to advance a mechanistic and quantitative understanding of how soil fauna communities contribute to soil functioning. Linking measurable organismal functions to ecosystem services will provide a basis for incorporating soil biodiversity into ecosystem assessments, soil process models and sustainable land-management strategies.

Convener: Cornelia Rumpel | Co-conveners: Nicolas Bottinelli, Francois-Xavier JolyECSECS, Quang Pham VanECSECS
SSS4.13

Soils host the largest reservoir of biodiversity on Earth, sustaining an intricate food web that spans from viruses and microbes to protists, nematodes, microarthropods, and other soil fauna. Together, these organisms regulate several soil functions with direct consequences for plant, animal, and human health. However, soil biodiversity remains comparatively understudied relative to aboveground biodiversity, and important taxonomic, spatial, and temporal gaps still limit our capacity to understand and predict how soil communities respond to global change.
In recent years, soil biodiversity has risen rapidly on both the scientific and political agenda, reflected in a surge of high-impact publications and in policy developments such as the EU Soil Monitoring Law. At the same time, soil biodiversity faces mounting pressures from land-use intensification, climate change, conventional agricultural management, and the spread of emerging pollutants and other anthropogenic contaminants.
This session aims to bring together researchers working across the full spectrum of soil biodiversity research, from fundamental ecology to applied and methodological innovation. We welcome contributions addressing (but not limited to):
- Patterns, drivers, and dynamics of soil biodiversity across different taxa and across spatial and temporal scales, including responses to climate and land-use changes.
- Impacts of agricultural practices (i.e., tillage, fertilization, etc) on soil biota and soil health, including the transition towards sustainable, solar energy, regenerative, and smart agricultural management.
- Effects of metals and emerging pollutants (microplastics, antibiotics, pesticides, PFAS, etc) on soil organisms and ecosystem functioning.
- Soil biodiversity–ecosystem functions relationships.
- Novel methodological and technological approaches for characterising soil biodiversity, including molecular/genomic tools, automated/high-throughput organism identification, remote sensing and UAV-based approaches, machine learning or integrative modelling frameworks.
- Smart and precision agriculture approaches that integrate soil biodiversity monitoring into decision-making for sustainable land management.
- Soil biodiversity as a nature-based solution for restoration, climate mitigation, and sustainable land management. Also, their link with policy, monitoring frameworks, and soil health indicators.

Convener: Andrés Rodríguez-Seijo | Co-conveners: Alicia Morugán-Coronado, Claudia Campillo-CoraECSECS
SSS4.14

How soil fauna are sampled shapes what we know about them. Soil cores, extraction funnels, pitfall and pan traps, hand sorting and DNA-based approaches each capture a different fraction of the community, with different biases, costs and impacts, which limits comparability across studies. New technologies, including smart and automated traps, in situ and non-destructive detection, low-cost open-source devices and DNA-oriented sample collection, promise more scalable and reproducible sampling, but need validation and standardisation. Robust, comparable methods are also needed to support soil monitoring under Directive (EU) 2025/2360, which requires scientifically validated methods without prescribing taxa.
This session focuses on the sampling step: how soil animals are collected, extracted, preserved and documented. We welcome contributions on (i) sampling design and effort optimisation; (ii) comparison of extraction and trapping methods and preservatives; (iii) smart, automated and robotic sampling devices; (iv) in situ and non-destructive detection (imaging, tomography, acoustics, sensors); (v) low-cost, open and citizen-science tools; (vi) DNA-oriented collection and preservation, including non-destructive recovery from trap fluids; (vii) ethical, low-impact and non-lethal sampling; (viii) standardisation, ring tests, reference materials and FAIR metadata; and (ix) transferability across soils, climates and land uses. Method comparisons and negative results are especially welcome.
This session is dedicated to the memory of Prof. Dr. Vittorio Parisi, author of the QBS-ar index (2001), who showed how a simple, standardised sampling-to-index workflow can make soil microarthropods a practical tool for assessing soil quality.

Convener: Alicia Morugán-Coronado | Co-conveners: Sara Remelli, Cristina García-HernándezECSECS, Andrés Rodríguez-Seijo
BG7.1

Plants and microorganisms in human space exploration play a key role in Bio-regenerative Life Support Systems (BLSS) for resource regeneration, food production, and crew well-being. Establishing sustainable extraterrestrial ecosystems requires an integrative understanding of how multiple space factors influence biological processes and bioregenerative elemental cycles in orbital platforms and planetary habitats.
This session focuses on plant and microbial responses to space factors, including altered gravity, ionizing radiation, and extreme geochemical constraints (e.g., regolith for In-situ Resource Utilization – ISRU), associated with spaceflight and planetary habitats. Altered gravity and ionizing radiation can affect metabolic, morpho-functional, and reproductive traits. When combined with unconventional growth substrates (e.g., lunar and Martian regolith), modified pressure, limited volumes, and reduced resources, these stressors produce complex, non-linear biological responses.
We invite contributions covering, but not limited to:
• Space Plant Biology: Molecular, epigenetic, morpho-anatomical, and physiological responses for acclimation and adaptation of plants to real or simulated space stressors
• Space Microbiology: Molecular, cellular, and other physiological and evolutionary responses of microorganisms to factors in BLSS
• Crop Performance and stress physiology in controlled systems
• Plant-Microbe Interactions & Microbiomes: Dynamics of microbial communities, plant-pathogen relationships, and the role of beneficial microorganisms in space cultivation
• ISRU & Pedogenesis: Regolith processing, bio-weathering, biomining, phytomining, organic matter accumulation, and the biotransformation of planetary materials into synthetic fertile soils
• Biogeochemical Cycling in BLSS: Nutrient dynamics (C, H, O, N, P, S, water, trace elements) and closed-loop life support system integration
• Experimental Platforms & Translation: Results from spaceflight missions, ground-based analogs, predictive modeling, and translation into strategies
• Planetary protection: Technologies, methods, and strategies to minimize the risks of forward contamination by microorganisms used in, or associated with, BLSS
By bridging plant biology, geomicrobiology, biogeochemistry, astrobiology, and space engineering, this session aims to advance an integrative understanding to drive sustainable deep-space exploration while informing solutions for resilient terrestrial agriculture.

Co-organized by PS6/SSS4
Convener: Veronica De Micco | Co-conveners: Cyprien Verseux, Chiara AmitranoECSECS, Lucie Poulet
ERE4.14

The current energy, climate, and geopolitical crises underscore the urgent need to develop carbon-free natural resources, with natural hydrogen as one of the most promising candidates. However, fundamental knowledge gaps persist regarding the complex, interconnected geological, geochemical, and microbiological processes that govern its generation, migration, accumulation, preservation, and seepage. This session aims to improve our understanding of the natural hydrogen cycle through the integrated interpretation of multi-scale (from laboratory to field scale) and multi-disciplinary observations. Contributions should present novel or established methods to: 1) reliably distinguish geological from non-geological (microbial and artificial) hydrogen sources; 2) link surface geochemical, microbiological and/or geophysical signatures to subsurface processes and migration pathways; 3) quantify the hydrogen generation and consumption/degradation rates to assess its potential as a sustainable energy resource; and 4) Improve current models of the natural hydrogen cycle. We invite contributions from researchers applying surface geochemical, microbiological, subsurface geophysical exploration techniques, as well as integrated multi-disciplinary approaches including modelling to reduce ambiguities in data interpretation and improve predictive capabilities for natural hydrogen systems.

Co-organized by BG1/GMPV6/SSS4/TS10
Convener: stephane Polteau | Co-conveners: Meike Bagge, Alexandra OrbanECSECS, Stefan SfabuECSECS, Roxana MogaECSECS
HS10.5 EDI | PICO

How do soil-plant-atmosphere interactions shape hydrological and vegetation responses to climate extremes? How do antecedent soil-water and vegetation conditions influence the pathways through which droughts, heatwaves and floods affect agricultural and natural systems? Which approaches can explain contrasting responses and improve predictions?
This session explores soil-plant-atmosphere processes and hydrological pathways during the onset and development of climate extremes and subsequent recovery. We examine links between meteorological forcing, antecedent system states, plant water use, land-atmosphere exchanges and hydrological responses, from field to catchment scales. We welcome studies of contrasting responses under dry and wet conditions, drought-heat interactions and transitions between extremes.
Topics of interest:
1. Soil-plant-atmosphere responses and feedbacks. Root water uptake, plant water regulation, evapotranspiration, canopy energy balance and vegetation stress during droughts, heatwaves and excess water, including soil-water supply and atmospheric demand interactions.
2. Antecedent conditions and hydrological pathways. How soil moisture, root-zone water storage, vegetation condition and groundwater connectivity shape responses to extremes; how water storage and partitioning among evapotranspiration, drainage, recharge and runoff link plant water availability to broader hydrological behaviour.
3. Contrasting extremes, event sequences and recovery. Contrasting responses under different initial conditions; drought-to-flood transitions; compound hot-dry conditions; and hydrological and vegetation recovery: timing, thresholds and legacy effects.
4. Observation-informed process understanding and prediction. Combining observations and models to identify response pathways, test process explanations, link spatial scales and assess predictive performance across events and environmental conditions.
We welcome research using satellite and uncrewed aircraft system (UAS) remote sensing, field experiments, process-based models, data assimilation and interpretable or hybrid machine learning, especially integrating soil-water, vegetation, surface-flux and hydrological observations.
Studies may examine single extremes or processes or compare events and systems. We link soil-plant-atmosphere and hydrological extremes research to explain how initial conditions and interacting processes shape responses and recovery.

Co-organized by BG3/NH13/SSS4
Convener: ruodan zhuangECSECS | Co-conveners: Salvatore Manfreda, Yijian Zeng, Sheng Wang, Lijie ZhangECSECS

SSS5 – Soil Chemistry and Organic Matter Dynamics

Sub-Programme Group Scientific Officers: Anna Gunina, Francisco Jesús Moreno Racero, Layla Márquez San Emeterio

SSS5.1

Enhanced weathering (EW)—the application of crushed silicate rocks to soils and other terrestrial environments—has emerged as a promising approach to atmospheric carbon dioxide removal, with estimates suggesting the potential for gigaton-scale removal annually. Research in this field is advancing rapidly, yet substantial uncertainties remain, ranging from dissolution kinetics in soils to the transport, transformation, and fate of weathering products in soil and freshwater systems. Building on the scientific exchange initiated during the previous edition, this session aims to continue providing a forum for advancing research and discussion on these challenges. We invite theoretical, experimental, modeling, and field-based contributions addressing not only the carbon removal potential of EW, but also its environmental co-benefits, possible risks, monitoring and verification, and applications in understudied regions. By bringing together diverse disciplinary perspectives, the session aims to foster collaboration and advance a more comprehensive understanding of EW's role in scalable, safe climate mitigation.

Convener: Matteo Bertagni | Co-convener: Xavier Dupla
SSS5.2

Soil organic matter is chemically diverse and continuously transforms, presenting a matrix whose composition and reactivity regulate key soil processes. The chemical composition of SOM determines whether compounds are rapidly transformed, persist through mineral association, fuel microbial activity, or participate in nutrient cycling, but these relationships are highly context-dependent and can vary with environmental conditions, land-use, and soil properties. This session brings together research exploring how the chemical complexity of SOM controls its transformation, persistence, and function, bridging molecular-scale processes and soil and ecosystem biogeochemistry. Studies investigating the composition, accessibility, and reactivity of SOM and dissolved organic matter using spectroscopic, isotopic, molecular, and fractionation approaches, as well as research linking SOM chemistry to microbial transformation, mineral–organic interactions, aggregation, nutrient cycling, and carbon stabilization are welcome. We encourage contributions on particulate and mineral-associated organic matter, microbial necromass, mineral surface interactions, organo-mineral associations, and molecular biomarkers that reveal SOM composition and reactivity across scales.

Convener: Anna Gunina
SSS5.3 EDI

Soils harbor a highly diverse spatial organization that shapes biogeochemical processes and ecosystem functions across scales. For example, these span from microbial habitats, organic and mineral surfaces, detritusphere and rhizosphere to soil aggregate structures and chemical gradients shaped by pedogenic and anthropogenic processes, all influencing the transformation and persistence of organic matter, nutrients other elements. In this session, we invite diverse empirical, synthesis, and modeling studies that address how biological, physical, and chemical hotspots and hot moments shape soil organic matter dynamics, soil biogeochemistry and ecosystem functions.

This includes studies that resolve biogeochemical hotspots across spatial and temporal scales to elucidate the mechanisms controlling soil organic matter storage, persistence, and vulnerability. We welcome contributions integrating diverse biological, physical, and geochemical perspectives, from targeted experiments and high-resolution observations to long-term studies, large-scale syntheses, and integrative modeling. Emerging approaches that combine novel analytical or computational methods, including AI and machine learning, with experimental and observational data are particularly welcome. We aim to bring these perspectives together to advance a cross-scale understanding of how soil heterogeneity and architecture shape organic matter dynamics and ecosystem functions.

Convener: Steffen A. SchweizerECSECS | Co-conveners: Edith Hammer, Mike RowleyECSECS, Marcus SchiedungECSECS, Sara KönigECSECS
SSS5.4

Carbon can persist in the environment for a few years to millennia, depending on the mechanisms that stabilise it. Persistence is increasingly understood not as an intrinsic property of a particular molecular makeup, but as an emerging quality reflective of the physical, mineralogical, microbial and environmental context in which carbon resides. Resolving these controls across the diversity of carbon pools is fundamental to predicting how ecosystem carbon stocks will respond to climate and land-use change over time.

This session focuses on the processes that determine the durability of carbon across terrestrial systems. We welcome contributions on the stabilisation of soil organic carbon, including the divergent turnover of mineral-associated (MAOM) and particulate (POM) organic matter and the roles of mineral surfaces, aggregate occlusion and microbial processing; the long-term stability of pyrogenic and biochar carbon; the fate of inorganic carbon generated by silicate weathering, including dissolved inorganic carbon and pedogenic carbonate; and the redox- and moisture-controlled preservation of carbon in peatlands and wetlands, where the balance of aerobic and anaerobic decomposition affects carbon accumulation and loss.

We invite studies that utilise field observation, manipulative experiments, isotopic and radiocarbon tracing, spectroscopy, modelling, or novel approaches to illuminate the timescales of carbon persistence and its vulnerability to disturbance. Insights that unify understanding across these otherwise separately studied pools are especially encouraged.

Convener: Monica McCallECSECS | Co-conveners: Robert BrownECSECS, Charlie J. DavisECSECS
SSS5.5

Soils are the largest terrestrial carbon reservoir, and enhancing the long-term persistence of soil organic matter (SOM) is a key strategy for mitigating atmospheric CO₂ concentrations. Yet, the mechanisms that govern SOM stabilization—and the interventions that might enhance it—remain among the most complex and debated challenges in soil science.
Recent advances have deepened our understanding of SOM fractionation and protection mechanisms, particularly the role of mineral-associated organic matter (MAOM), particulate organic matter (POM), and occluded POM (oPOM). Insights into the biotic and abiotic pathways leading to MAOM formation have expanded significantly, alongside the development of new-generation soil models that incorporate these processes into SOM turnover estimates.
At the same time, emerging evidence underscores the complex and context-dependent nature of the soil mineral–microbe–vegetation interface. In particular, studies beyond temperate systems reveal that organo-mineral interactions are more dynamic than previously assumed, and that POM can persist for centuries in certain ecosystems or soil horizons. These findings challenge conventional assumptions and highlight the need for tailored management strategies.
This session invites contributions that explore SOM dynamics across scales—from molecular mechanisms and microbial processes to ecosystem-level patterns and global models. We welcome studies that introduce novel insights, challenge established paradigms, or provide robust confirmations of existing theories. Whether your work is based on field observations, laboratory experiments, or computational modeling, we are eager to hear how it advances our understanding of SOM persistence and informs practical applications, from land management to climate policy.
We particularly encourage early career scientists to participate, including those with preliminary findings or innovative conceptual approaches. If your research touches on any aspect of SOM formation, transformation, or stabilization, join us for a lively and interdisciplinary discussion.

Convener: Boris Jansen | Co-conveners: Karen Vancampenhout, Beatrice GiannettaECSECS, Noelia García FrancoECSECS
SSS5.6

The interaction of the carbon cycle and other biogenic elements in the soil determines the overall biogeochemical stability and productivity of terrestrial ecosystems. Transformations among C and N, P, S, Ca, Mg, Fe, and Al are closely coupled through organic matter turnover, mineral weathering, sorption and desorption, complexation, precipitation and dissolution, and redox reactions; these processes regulate element availability, mobility, retention, and losses. This session brings together studies investigating the coupled biogeochemistry of carbon, nutrients, and major elements across soils and ecosystems. We welcome research addressing element interactions at molecular, mineral, microscale, and ecosystem levels, using spectroscopic, isotopic, molecular, and modeling approaches. We particularly encourage contributions linking elemental coupling with mineral–organic interactions, such as C-Fe, C-Ca, and C-Al; microbial processes governing C-N-P cycling in soil; nutrient availability for plants and interactions in the plant-soil-microorganism system; weathering; organic matter transformation under redox dynamics; and responses of C and nutrient cycling to environmental change and soil management.

Convener: Layla Márquez San EmeterioECSECS | Co-convener: Anna Gunina
SSS5.7

Soil organic matter (SOM) is the largest terrestrial organic carbon pool and a key lever for climate regulation, yet the mechanisms governing its dynamics and long-term persistence across contrasting scales remain debated. A paradigm shift over the last two decades has moved the field from viewing SOC persistence primarily as a function of intrinsic molecular recalcitrance towards a framework in which physical organization and microbial accessibility control turnover times. Resolving how carbon moves from fresh inputs through particulate (POM) to mineral-associated organic matter (MAOM), and where and why it is stabilized or lost, across ecosystems and along the soil–regolith profile, requires integrated, multi-proxy approaches combining methods from soil science, biogeochemistry and isotope geochemistry.
This session aims to bring together researchers working along the full SOC continuum and adopting multidisciplinary approaches to disentangle the formation and fate of SOC by investigating SOM chemistry, mineral soil characteristics, physical organization and mineralogy. We invite studies that (i) investigate SOC persistence across contrasting spatial and temporal scales; (ii) trace SOM formation and transformation using classical and non-traditional molecular and isotopic approaches; (iii) apply emerging non-traditional methods, including stable isotope systems of mineral elements, to trace mineral transformation and organo-mineral interactions along the critical-zone profile; and (iv) use models across contrasting scales to integrate data generated by different approaches.
We particularly encourage studies combining these complementary approaches to constrain mechanisms of long-term SOC preservation, including studies of Quaternary archives such as loess–paleosol sequences.
By bringing together communities from different disciplines, the session seeks to advance a unified, process-based understanding of SOC dynamics by integrating short-term turnover with long-term stabilization. Such an integrated perspective is essential for assessing the persistence of carbon across contrasting soil types and climates and its responses to environmental change, and for underpinning robust climate and land-management strategies. We particularly encourage submissions from early-career researchers and under-represented regions, and invite contributions that could form the basis of a topical collection in Biogeosciences or SOIL.

Convener: Chao SongECSECS | Co-conveners: Cornelia Rumpel, Guilin Han, Abad Chabbi
SSS5.8

Soils represent a major terrestrial store of both organic and inorganic carbon. At present soils are a net carbon sink, and building soil carbon stocks holds a potential to contribute to achieving net zero carbon. Furthermore, the accrual, stability, and cycling of carbon is fundamental to the productivity and resilience of soil systems, and preserving or even increasing soil carbon stocks is critical for allowing sustainable agricultural crop production.

Avenues for organic carbon sequestration in soils include plant-based inputs, the addition of pyrogenic carbon (biochar), and addition of composts or other additives such as manures and soil conditioners provided additionality and leakage effects are considered. Enhanced silicate weathering may hold significant potential for building up inorganic carbon stocks, while inputs from bedrock, and mediation by land use changes such as afforestation, may also increase inorganic soil carbon stocks.

This session seeks to explore how soil carbon stocks can be increased so as to simultaneously enhance agricultural productivity, mitigate negative repercussions of changing environmental conditions, and contribute to achieving carbon neutrality. In addition to organic carbon, focus will be given to inorganic carbon pools in agroecosystems and their response to management practices such as fertilisation, irrigation, liming, or other mineral additions. Alongside this, advances in methods for monitoring and modelling rates of soil carbon loss or carbon sequestration in soils will be discussed, including approaches to quantify and characterise organic and inorganic carbon in calcareous soils. We welcome contributions exploring methods of increasing both organic and inorganic carbon stocks, and studies exploring the storage, stability, and cycling of carbon within soil systems. Early career researchers are strongly encouraged to apply, and we seek submissions considering empirical, modelling, or meta-analytical approaches.

Convener: Chris McCloskeyECSECS | Co-conveners: Dan Evans, Felix Seidel

SSS6 – Soil Physics

Sub-Programme Group Scientific Officers: Frederic Leuther, Vincent Felde, Lizeth Cardoza-Pedroza

SSS6.1

Soil health can be assessed in many ways, depending on the perspective from which the soil is considered. It may focus on the biological diversity and activity of different soil organisms, and their ability to contribute to soil functions such as nutrient availability, or the presence or absence of pollutants. Soil can also act as a buffer for various substances and act as the transport medium for the transport of water, solutes and particles. However, hardly ever is soil health looked at through a soil physics lens, which is the aim of this session. The goal is to identify the “physics-shaped” knowledge gaps and blind spots in the field of soil health and discuss what contributions the discipline of soil physics has to offer, beyond bulk density.

We are looking for contributions addressing topics like:
- What are current methods to understand soil health, and how can they be related to physical soil properties and processes?
- What are promising parameters (besides texture and bulk density) that can serve as physical proxies for soil health?
- What could simple field-tests be?
- Would there be a need to adapt physical soil health indicators for different textures?
- How can soil physics contribute to accessible and interdisciplinary approaches for monitoring soil health?

Convener: Vincent Felde | Co-conveners: Lizeth Cardoza-PedrozaECSECS, Frederic Leuther
SSS6.2

Soil structure and its stability are important aspects of soil health as they regulate key soil physical, chemical, and biological functions. This includes water retention, hydraulic conductivity and gaseous transport, nutrient cycling, redox dynamics, erosion resistance, and root penetration. The arrangement and connectivity of pores, minerals, and organic matter govern the exchange of water, gases, and solutes within soils and provide habitat for soil biota, which in turn actively modify and engineer the pore network. These interactions create dynamic feedbacks between soil structure and ecosystem functioning.

Soil structure evolves continuously across spatial and temporal scales through the action of roots, soil organisms, land management, and abiotic drivers such as wetting and drying cycles. These processes alter pore architecture and aggregate organization, thereby modifying soil properties and functions over time. Recent advances in imaging, geophysical methods, experimental approaches, and process-based modelling have substantially improved our ability to observe and quantify these dynamics. Nevertheless, many of the mechanisms linking soil structure development, degradation, resilience, and soil functioning remain poorly understood.

Understanding the processes and feedbacks governing soil structure dynamics is essential for developing climate-smart and resilient soil management strategies. In this session, we invite contributions on the formation, stabilization, degradation, and evolution of soil structure and its associated functions across all spatial and temporal scales. We particularly encourage contributions integrating complementary measurement techniques (e.g., geophysics, digital image correlation, X-ray CT), novel modelling concepts, or approaches that bridge scales.

Special focus lies on:
• feedbacks between soil structure dynamics and soil biology,
• effects of land use and management on soil structural development and associated soil functions,
• biological, hydrological, and mechanical processes shaping pore architecture and structural resilience,
• integration of complementary measurement techniques and modelling approaches across scales.

Co-organized by HS13
Convener: Loes van Schaik | Co-conveners: John Koestel, Frederic Leuther, Max BehringerECSECS
SSS6.3

Soil is a dynamic porous media in which its structure plays a key role in controlling soil functionality. As many functions are related to the transport and storage of fluids, we often focus our research in soil physics on the pore space itself ignoring the delicate yet dynamic structure of interconnected solid particles. In this session we aim to look at the mechanical properties and processes that lead to soil structure formation, stabilisation and degradation on various scales ranging from interparticle to bulk/pedon-scale including the assessment of mechanical soil properties on field to regional-scale. We are looking for contributions addressing topics like:

- root/fauna-soil bioturbation mechanical processes and the energic inputs required to generate biopore spaces/structures
- stabilising mechanisms in the rhizosphere and mechanical reinforcement of soil by root networks, rhizodeposition, or microbial extracellular polymeric substances
- the role of pore water pressures and matric potential on soil deformation
- Mineral (grain-grain) / organic-mineral interactions and how they are controlled by the chemistry of pore water and surface charges
- Soil compaction assessment in forestry (skidding tracks) and agricultural soil management including new approaches to model/estimate spatial distribution of (sub)soil compaction
- The effects of compounds, colloids, or microplastics on soil aggregate stability and mechanical behaviour
- Modern and emerging techniques like rheometry, digital image correlation, diffraction stress measurements, aggregation and deformation modelling as well as geophysical approaches to assess soil compaction from the profile to the field scale

Convener: Siul Ruiz | Co-conveners: Vincent Felde, Nasrollah Sepehrnia, Markus Berli
SSS6.4

Life in soil modifies its physical environment to optimize growth and reproductive conditions. Especially in hotspots of biological activity, soil organisms induce remarkable alterations in soil structure and functions. Elucidating the underlying mechanisms forcing such adaptive modifications, and exploring the feedbacks between the drivers, offers an exceptional opportunity to advance our understanding of fundamental physical and biological processes across scales.
We seek contributions linking biological processes and soil physics at any spatial and temporal scale. For example, insights into how the rhizosphere and its microbiome control fluxes beyond the pore scale; on the role of biological soil crust in regulating infiltration and limiting soil erosion across vast areas of the earth’s surface; on how bioturbation shapes soil hydraulic characteristics over years and decades.
Topics of the Soil Biophysics session include but are not limited to:
1. Root growth
2. Microbial activity
3. Bioturbation
4. Virus dispersal
5. Resource allocation
6. Soil water dynamics
7. Soil structure formation
8. Biological soil crusts
9. Rhizosphere interactions
10. EPS (incl. mucilage)

The aim of this session is to highlight the potential of interdisciplinary approaches to address current and future challenges in soil science and to foster scientific exchange across disciplines.

Convener: Pascal Benard | Co-conveners: Samuel BickelECSECS, Sara Di BertECSECS, Sara Bonetti, Dani Or
SSS6.5

The type of flow (homogeneous versus preferential flow) is expected to have a major impact on pollutant transfer. We expect homogeneous flow to favor pollutant access to reactive particles and, thus, enhance pollutant retention. Preferential flow also called macro-pore flow, non-equilibrium, unstable flow or funnel and fingered flow, happens when water and solutes move through a porous medium with a limited number of fast pathways instead of having a uniform distribution. These pathways can be induced by biotic (e.g. earthworm and roots) and abiotic factors and processes (e.g. wet-dry and freeze-thaw cycles, lithology and structure) and they vary in space and time. They can carry substantial movement of water and solutes in both vertical and horizontal directions under saturated or unsaturated conditions and can dominate the flow and transport processes across a wide range of scales. As a result, preferential flow may regulate the mobility, distribution or removal of solutes, nutrients or contaminants. Similarly, preferential flow may affect the efficiency of salt precipitation or dissolution processes. Understanding preferential flow processes cannot be overstated, considering its relevance to the fate and transport of solutes, nutrients and contaminants in agricultural land, landscapes, catchments, mine waste covers and tailings storage facilities.
This session welcomes studies on experimental and theoretical challenges to identify, quantify, and model the effect of flow type on solute, nutrient and contaminant transport in porous media (e.g. soil, mine wastes, waste rocks and rocky and gravelly materials) across scales (from pore scale to catchment scale). The session accepts studies on but not limited to the following topics:
• Effects of flow type within the soil-plant-atmosphere continuum and their consequence for solute, nutrient or contaminant transport in the saturated and unsaturated zone;
• Coupling the physical processes of preferential flows and geochemical processes for improving the understanding of solute sorption and desorption, mineral precipitation and dissolution;
• Modelling of different types of flow and their effects on mass transport across scales, from pore to pedon scale and entire catchments and landscapes.
• Transport of particles and colloids, including nanoparticles, and the influence of flow type, in particular preferential and non-uniform flow, on their mobility, retention and remobilization.

Co-organized by HS13
Convener: Lizeth Cardoza-PedrozaECSECS | Co-conveners: Uwe Schneidewind, Fuad AlqrinawiECSECS, Simone Di Prima, Laurent Lassabatere
SSS6.6

Preferential and non-uniform flows are widespread features of natural and engineered porous media and may arise from biotic factors, such as roots and soil fauna, abiotic processes including wetting-drying and freeze-thaw cycles, lithological and structural heterogeneity, as well as anthropogenic activities such as tillage, cultivation practices and landforms construction. Preferential and non-uniform flows can strongly affect water redistribution and the transport of solutes, nutrients and contaminants. Preferential flow pathways may develop and interact over a wide range of spatial scales from the pore scale to soil profiles and entire catchments, while their occurrence and relevance may vary over time, from individual hydrological events to seasonal and interannual dynamics.
This session welcomes experimental, theoretical and modeling studies aimed to improving the understanding, characterization and quantification of preferential and non-uniform flows in porous media across scales. Contributions are welcome on:
• Understanding the geometry, connectivity, formation and temporal dynamics of flow in fissures, fractures, macropores and other preferential flow pathways;
• Understanding the role of physical, biological and geochemical processes in the dynamics of macropores and fracture networks;
• Experimental methods for characterizing heterogeneous pore structures and hydraulic properties, including tracer, imaging, and infiltration-based approaches;
• Conceptual, analytical and numerical approaches for modelling preferential water flow from pore and pedon scales to hillslopes, catchments, and landscapes;
• Approaches linking measurements and models and addressing spatial heterogeneity, temporal variability, and scale transitions in preferential flow processes.
• Development of non-invasive and geophysical techniques, including electrical resistivity tomography and ground penetrating radar for identifying and monitoring preferential flow pathways in porous media.

Convener: Dario Autovino | Co-conveners: Laurent Lassabatere, Simone Di Prima, Giuseppe Brunetti
SSS6.7

Subsoils - defined as soil layers below 30 cm or mineral soils - contribute to more than half of the total soil carbon stocks and store substantial amounts of nutrients and water. Despite the critical ecosystem services they provide, including long-term carbon storage, water and nutrient supply to plants, and habitat for biological communities that can differ from the topsoil, they remain under-represented in research. The under-sampling is usually justified by assuming a negligible contribution to ecosystem services. A key factor underpinning many of these ecosystem services is the structural connectivity between topsoil and subsoil, particularly the continuity of macropores, mainly biopores (e.g. earthworm burrows and root channels), which influences water infiltration, root access to deeper horizon and nutrients resources, and the transport of solutes. Compared with the topsoil structure, which can be regularly disturbed (e.g. tillage) and reformed, the subsoil structure might persist over longer timescales and changes slowly unless woody perennials are present, making it a potentially important lever for soil management and climate change adaptation under increasing climate variability and uncertainty. Yet, subsoil properties, functions and their dynamics remain poorly characterized and quantified.

In this session, we aim to bring together studies across disciplines, including soil physics, soil biology, hydrology and biogeochemistry and the connectivity to land use and land management to shed light on the subsoil structure and dynamics and, more broadly, on the role of subsoils in terrestrial ecosystems. We invite experimental, observational, and modeling studies exploring subsoil processes and structural dynamics, including interaction between biological drivers (e.g. roots, soil fauna and microorganisms) and hydrological, carbon and nutrient cycling processes across agricultural, grassland, forest and other terrestrial ecosystems.). Particular attention will be given to studies that highlight the importance of subsoils and the structural pathways connecting them to the broader soil–plant–atmosphere system. We also welcome, imaging studies, synthesis work and reviews addressing deep soil horizons and their roles in nutrient cycling, climate change responses, and ecosystem resilience.

Co-organized by HS13
Convener: Sarah Smet | Co-conveners: Yacouba ZiECSECS, Rosa Mosquera-Losada, Miriam Athmann, Thomas Keller
HS9.2

Soil erosion is a key driver of land degradation, leading to a cascade of impacts from on-site soil loss and reduced agricultural yields to off-site consequences such as flooding and sediment and contaminant pollution of aquatic environments. The environmental, economic, and societal impacts of soil erosion require a comprehensive scientific understanding of the physical processes controlling soil detachment, transport, storage, and redistribution from hillslopes to catchments, lakes, and estuaries.
This cross-disciplinary session covers the latest scientific developments in soil erosion and sediment delivery. By integrating hydrology, geomorphology, soil sciences, and biogeosciences, we aim to unify all driving forces of land degradation and catchment particle-bound transport.
Our goal is to bridge the gap between plot-scale soil loss and catchment sediment routing, linking short-term monitoring with long-term observations. Advancing this process knowledge connects methodological developments to conceptual frameworks, promoting sustainable management.

The following topics will form the core areas of presentation and discussion:
• Measurements and Tracing: Field and lab experiments developing process understanding (e.g., interrill to gully erosion) and catchment sediment tracing techniques.
• Monitoring: Short- to long-term assessments tracking landscape changes via local field assessments, UAS, and broad-scale remote sensing.
• Modelling Approaches: Innovative simulation techniques, from empirical and process-based to data-driven, addressing runoff, gully erosion, sediment transport, and catchment sediment budgets from plot to global scales under current and future climate scenarios.
• Sediment and Contaminant Dynamics: Quantification of sediment transit or residence times, storage, remobilisation, and the biogeochemical controls of associated contaminant transport impacting riverine and lacustrine ecosystems.
• Mitigation, Restoration and Impacts: Evaluation of conservation strategies, including successes and failures in addressing the on-site and off-site impacts of land use change and disturbances (e.g., agriculture, forestry, mining, urbanisation, wildfires).
Ultimately, we explore conservation strategies that support stakeholders and global initiatives, including the EU Soil Monitoring Law, Land Degradation Neutrality by 2030, and the UN Decade on Ecosystem Restoration (2021-2030).

Co-organized by GM5/SSS6
Convener: Tirusew AbereECSECS | Co-conveners: Olivier EvrardECSECS, Amaury Frankl, Vesna Zupanc, Ivan LizagaECSECS
HS1.2

This session pays tribute to Hannes Flühler - a scientific leader and mentor, and the 2004 EGU John Dalton Medalist. The session celebrates Hannes’s many contributions to soil physics and vadose zone hydrology. His creativity and optimism in addressing flow and transport processes in unsaturated porous media were always guided by the cautionary principle of “digging deeper”. Meaning that we must revert to physical fundamentals and question incomplete explanations to observations.
His approach is even more relevant today where artificial intelligence and computational capacity transform data analysis and modelling, enabling consideration of increasingly complex scenarios across hydrology, land-surface science, plant physiology and agronomy. Meanwhile, societal expectations concerning soil health, ecosystem resilience and food security create new demand for rigorous soil physics offering new opportunities, but also a risk that sophisticated computations may obscure fundamental gaps in understanding. An illustrative example of these contemporary challenges is taken from work of Hannes Flühler (Flühler et al., 1976). Field measurements of unsaturated hydraulic conductivity differ markedly from laboratory measurements and model predictions, which naturally raise questions about the transferability of hydraulic descriptions from laboratory to field conditions. The example motivates us to take a deeper look at the physical basis and applicability of our description of soil processes.
In the spirit of Hannes Flühler’s approach, we invite contributions that dig deeper into fundamental questions in soil physics and hydrology. We encourage early career scientists and students to submit their work to this session. We welcome experimental, theoretical and computational studies that investigate discrepancies between observations and predictions, examine how soil structure and moisture history affect flow and transport, and test the transferability of hydraulic descriptions across scales and changing environmental conditions.

Flühler, H., Germann, P., Richard, F., & Leuenberger, J. (1976). Bestimmung von hydraulischen Parametern für die Wasserhaushaltsuntersuchungen im natürlich gelagerten Boden. Ein Vergleich von Feld‐und Laboratoriumsmethoden. Zeitschrift für Pflanzenernährung und Bodenkunde, 139(3), 329-342.

Co-organized by SSS6
Convener: Dani Or | Co-conveners: Andrea Carminati, Peter Lehmann, Ute Wollschläger, Insa Neuweiler
HS8.3.5

The continuum approach is a classical framework to describe and understand the soil--water dynamics and the soil effective--stress state in unsaturated soils. This approach is robustly rooted in the definition of the soil--water constitutive laws (soil--water retention curve, soil hydraulic conductivity, Kirchhoff potential, etc.). They link the real soil and its model. Advancements along their development and the comprehension of their role stand at the intersection of experimental measurements, mathematical representation and modelling, numerical solutions, theoretical understandings and practical applications.

This session aims at stimulating an interdisciplinary discussion about the state of the art and recent advances about soil--water constitutive laws and soil physical and hydrological properties, in the framework of a continuum approach and contributing to define its limits.

Experimental, theoretical and numerical contributions are encouraged about, but not limited to, (1) scaling of soil--water constitutive laws and their changes in time and space as a consequence of seasonality, climatic changes, anthropogenic changes and pedogenesis; (2) physics of water--repellent soils, and of swelling, dispersive and collapsible soils; (3) constitutive laws for extremely dry conditions and for nearly saturated soils; (4) nonequilibrium and hysteretic behaviours; (5) limits of the Darcian approach in the presence of macroporosity; (6) heat transfer and dispersion; (7) freezing and thawing processes in permafrost; (8) mechanisms of incipient erosion; (9) mathematical functions of constitutive laws and their physical implications; (10) pedotransfer functions and database analysis.

Advancements along those lines will have major implications in many fields, ranging from hydrology, to soil science and soil physics, agriculture and geotechnics.

Co-organized by BG3/SSS6
Convener: Stefano Barontini | Co-conveners: Fatma Wassar, Martina Siena, Sana Ounaies
HS8.3.3 | PICO

Observing soil moisture at the ground is essential to assess plant available water, manage water resources and calibrate, validate satellite products or environmental models and conduct climate impact studies. Unfortunately, the availability of in situ observations is very limited in space and time. Whereas the spatial distribution is biased towards the global North, the temporal availability of soil moisture time series is on average 10 years as can be seen from the largest archive of in situ soil moisture, the International Soil Moisture Network (ISMN). Apart of the data availability issues, a substantial amount of the in situ observations face data quality issues that might result from sensor deployment, sensor calibration, data processing or other error sources.
This session will address issues in the development and deployment of state-of-the-art soil moisture observation networks, the financing of their long-term operation, data quality assurance, data imputation, and data scaling as well as sensor deployment and assessments of differences between these deployments. We further encourage contributions presenting developments of novel measurement techniques including citizen science initiatives and studies utilizing (primarily) in situ soil moisture to understand and assess hydrological processes, water availability, land-atmosphere feedbacks and soil moisture dependent hazards.

Co-organized by GI5/SSS6
Convener: Matthias Zink | Co-conveners: Justin Sheffield, Carsten Montzka, Alexander Gruber, Fay BöhmerECSECS

SSS7 – Soil Pollution and Reclamation

Sub-Programme Group Scientific Officers: Erika Santos, Tamara Apostolović, Diego Arán

SSS7.1

Plastic pollution in soils is a global issue of growing concern for scientific communities and the public alike. Soils are a major sink for plastics, with agricultural land ranking among the most polluted land-use categories. Despite this, significant knowledge gaps remain concerning the analysis of plastic in soil, its sources, and its fate. This session seeks to bridge these knowledge gaps, which is an essential step towards improving risk assessments, informing policies, guiding agricultural practices and industrial strategies to mitigate plastic pollution and its environmental impact. We welcome contributions from observational, monitoring, laboratory, and modelling studies from urban settings, agroecosystems, and soil interfaces between different environmental compartments, covering all scales from nano- to macroplastics, with a focus on:
• Detection of plastics in soil systems: methods for sampling, detection, and quantifying plastic pollution in soils.
• Distribution and source apportionment: monitoring efforts and source apportionment, spatio-temporal patterns
• Transport dynamics of plastics: transport of plastics and their co-transport with other contaminants from soil to other environmental compartments.
• Degradation of plastic in soil: physical and chemical degradation, photodegradation, biodegradation, additive leaching, and the sorption processes of other chemicals.
• Impact of plastic on soil ecosystems: physical and chemical interactions between soil and plastic particles, ecotoxicological effects of plastics and/or their leached additives on soil properties, soil health, plant growth and soil fauna.
• Economic and policy perspectives: economic drivers for agricultural plastic use, designing solutions, and supporting policies and regulations for reducing and sustainably managing agricultural plastics.

Research related to, but not explicitly listed above, may also be considered.

Convener: Melanie Braun | Co-conveners: Zacharias Steinmetz, Rachel Hurley, Peter Fiener
SSS7.2

Soils have been identified as a major sink for plastics which has led to increasing concerns for essential soil ecosystem services. However, we still lack an in-depth understanding of transport processes and the fate of macro-, micro-, and nanoplastics in the terrestrial environment. In this session, we invite contributions that present empirical, monitoring, and modelling studies for all scales of plastic pollution and soil systems, advancing our mechanistic understanding of transport and fate in the terrestrial environment. This includes but is not limited to urban settings, agroecosystems, and soil interfaces between different environmental compartments. Presentations may focus on:
• Experimental studies at different scales (lab, mesocosm, field, etc.) advancing our process-based understanding of transport and transformation processes
• Monitoring efforts to understand source attribution and quantification of spatiotemporal trends in inputs, releases, and transfers
• Models addressing fate and transport processes within terrestrial environments and their interfaces, such as connected aquatic and atmospheric systems
• Human behaviour, littering and littering dynamics, urban drainage systems, and solutions
We welcome interdisciplinary research, including contributions from the social sciences.

Convener: Christina Bogner | Co-conveners: Markus RolfECSECS, Wiebke Mareile HeinzeECSECS, Hannes Laermanns
SSS7.3

Soil ecosystems provide essential services, including nutrient cycling, water filtration, carbon sequestration, and habitat provision. However, industrial activities, intensive agriculture, mining, urbanization, and waste disposal have led to widespread accumulation of contaminants in soils globally.
From legacy pollutants such as potentially toxic elements and persistent organic pollutants to contaminants of emerging concern, soil contamination poses a growing threat to terrestrial biodiversity and agricultural productivity.
While extensive research has documented contaminant concentrations in soils, significant knowledge gaps remain regarding how pollutants alter fundamental belowground ecosystem processes and soil functioning, thereby affecting major processes on an ecosystem level. Contaminant mixtures, dynamic environmental conditions, and climate change stressors alter contaminant bioavailability, bioaccumulation pathways, and ecotoxicological impacts on microbial communities, soil fauna and vegetation. Furthermore, developing scalable, cost-effective, and ecologically sound remediation and management strategies requires a deep mechanistic understanding of soil-pollutant interactions and physiological responses of plants.
This session aims to bring together contributions from all aspects of soil pollution research, including methodological advances focused on the sources, distribution, ecological impacts, and sustainable management of soil pollutants.
We encourage interdisciplinary contributions that link physical and chemical pollutant characterization with plant responses, ecosystem function assessment, and novel remediation frameworks. Studies on the effects of soil pollution on ecosystem processes and biogeochemical cycles (e.g., carbon, nitrogen, and phosphorus dynamics) under pollution pressure are especially welcome, as are novel insights into processes governing bioavailability, trophic transfer, and soil-to-plant contaminant accumulation.
We welcome presentations of laboratory and field research results as well as theoretical studies. We intend to bring together scientists from multiple disciplines. We especially encourage young researchers to submit their contributions.

Convener: Oliver Wiche | Co-conveners: Carla Ferreira, Lyudmyla Symochko, Zahra Kalantari
SSS7.4

Soil contamination encompasses a wide range of inorganic and organic pollutants, including metals and metalloids, petroleum hydrocarbons, pesticides and other persistent organic contaminants, as well as emerging contaminants such as per- and polyfluoroalkyl substances (PFAS) and microplastics. The coexistence of multiple contaminants can increase the complexity of remediation and requires approaches capable of addressing contaminant-specific behaviour while supporting the recovery of soil functions.

Nature-based solutions (NbS) are increasingly being explored as sustainable approaches for the remediation and restoration of contaminated soils. These include the application of organic, mineral and engineered amendments, phytoremediation and plant-assisted remediation, microbial and bioremediation processes, as well as combinations of these strategies. Their effectiveness depends on the interactions between contaminants, soil properties, amendments, plants and microorganisms, and may involve contaminant immobilization, transformation, degradation, uptake or changes in bioavailability and mobility.

This session aims to bring together research addressing the application and development of nature-based approaches for the remediation of soils affected by a broad range of contaminants, from metals and metalloids to conventional organic pollutants and emerging contaminants such as PFAS and microplastics. Contributions addressing single or multiple contaminants, contaminant mixtures, soil–plant–microorganism interactions, amendment-based remediation, phytoremediation, bioremediation and integrated approaches are particularly welcome.

We also encourage contributions evaluating the long-term performance, mechanisms, scalability and environmental sustainability of nature-based remediation strategies, as well as their capacity to reduce contaminant risks and contribute to the recovery of soil functions. Interdisciplinary studies connecting contaminant biogeochemistry, soil science, environmental microbiology, plant science and remediation engineering are especially encouraged.

Convener: Diego BaragañoECSECS | Co-conveners: Rocío Barros, Diego Soto-Gómez, María AguinagaECSECS, Stella Cristiani Gonçalves Matoso
SSS7.5

Soil contamination by potentially hazardous substances (e.g. metals, metalloids, radionuclides, organic compounds and emerging contaminants) is one of the major environmental challenges affecting soil and plant health, ecosystem services, food production and sustainable land management, as well as promoting other forms of soil degradation (e.g. erosion, salinisation and loss of organic matter and biodiversity). Understanding the extent and effects of soil contamination is essential for developing sustainable land management and remediation strategies. Although several remediation approaches have been investigated, particularly on a laboratory and greenhouse scale, their long-term effectiveness and sustainability in real field conditions are largely unknown. The success of remediation should be evaluated based on the removal or immobilisation of contaminants, as well as the recovery of soil properties, biological activity, biodiversity and ecosystem services.
This session focus on the transition to soil remediation at medium- and long-term soil recovery, with a particular emphasis on assessing and monitoring recovery processes. The aim is to bring together interdisciplinary research addressing contaminant removal, immobilisation and dynamics, environmental risk reduction, recovery of soil functions, soil–plant–microorganism interactions, ecosystem services and overall soil health, as well as legal frameworks, limitations of remediation strategies, and sustainability assessment of remediation strategies.
The session provides an opportunity to present studies and establish new partnerships with the aim of developing multidisciplinary strategies to contribute to the assessment and remediation of contaminated sites.

Convener: Erika Santos | Co-conveners: Diego Arán, Raquel Cela DablancaECSECS, Maria Manuela Abreu
HS8.2.8

This session focuses on the use of geophysical methods for characterising subsurface properties, states and processes in hydrology, hydrogeology, Critical Zone, contaminant transport, ecology and beyond. Topics of particular interest include groundwater flow and storage, aquifer and soil heterogeneity, soil moisture and vadose zone dynamics, transport processes and surface water–groundwater interactions, as well as the influence of subsurface heterogeneity on biogeochemical processes and microbial biodiversity.
Geophysical methods can provide subsurface information at exceptionally high spatial and temporal resolution in a non-invasive manner. However, the interpretation of these measurements remains far from straightforward in many applications and a number of challenges persist. These include improving the quantitative use of geophysical measurements for hydrogeological model conceptualisation and parameterisation, resolving structural and hydraulic heterogeneity and extending quantitative hydrogeophysical investigations beyond laboratory and field scales towards the catchment scale.
We therefore welcome submissions addressing advances in the acquisition, processing, analysis and interpretation of data obtained from geophysical and other minimally invasive methods applied to hydrogeological, hydrological, biogeochemical and contaminant-related problems. In particular, we encourage contributions on innovative experimental and numerical methods supporting model–data fusion, new concepts for coupled and joint inversion, and advances in petrophysical understanding of the relationships between geophysical properties and hydrogeological parameters, states and processes.

Co-organized by SSS7
Convener: Ulrike Werban | Co-conveners: Deqiang Mao, Clara JodryECSECS, Damien Jougnot
HS9.1 | PICO

The transfer of sediments and associated contaminants plays an important role in catchment ecosystems as they directly influence water quality, habitat conditions, and biogeochemical cycles. Contaminants may include heavy metals, pesticides, nutrients, radionuclides, and various organic, as well as organometallic compounds. The environmental risk posed by sediment-bound contaminants is largely determined by the sources and rate at which sediments are delivered to surface water bodies, the residence time in catchments, lakes, and river systems, as well as biogeochemical transformation processes. However, the dynamics of sediment and contaminant redistribution is highly variable in space and time due to the complex non-linear processes involved. This session focuses on sources, transport pathways, storage, re-mobilization, and travel times of sediments and contaminants across temporal and spatial scales, as well as their impact on freshwater ecosystems.

This session particularly addresses the following key themes:
1) Sources and Pathways of Sediment and Contaminant Transfer
Understanding how sediments and contaminants originate from natural and human sources (e.g., agriculture, urban areas, mining, industry) and move through the land, river, lake, and reservoir continuum.
2) Transport Dynamics and Environmental Controls
Investigating the transport, retention, remobilization, and transformation of sediments and contaminants, including the influence of biogeochemical processes, human activities (such as hydropower and flood management), and changing environmental conditions.
3) Innovative and Cost-effective Monitoring and Modelling Methods
Developing and applying novel, low-cost, and open-source methods to quantify sediment and pollutant fluxes across different spatial and temporal scales.
4) Impacts on Ecosystems and Landscapes
Assessing how sediment and contaminant dynamics affect river systems, floodplains, riparian zones, in-stream ecosystems, landforms, and geomorphological processes.
5) Long-term Change and Human Influence:
Using sediment archives, sediment budgets, and catchment-scale analyses to evaluate historical trends and understand the effects of human activities and environmental change on sediment and contaminant dynamics over time.

Co-organized by GM4/SSS7
Convener: Ivan LizagaECSECS | Co-conveners: Amaury Frankl, Maarten WynantsECSECS, Laura Quijano, Marcel van der Perk

SSS8 – Soil, Environment and Ecosystem Interactions

Sub-Programme Group Scientific Officers: Mariano Moreno de las Heras, Emilio Rodriguez-Caballero

SSS8.1

Drought is a major driver of changes in soil-water availability and vegetation functioning, with impacts that vary across spatial and temporal scales. This session welcomes contributions investigating soil moisture dynamics and vegetation responses to drought across spatial and temporal scales. We invite studies using in-situ soil moisture sensors, field observations, proximal sensing, UAV and satellite observations, and environmental modeling to characterize soil-water availability and its links to vegetation functioning under water-limited conditions. Contributions addressing drought impacts on soil systems, soil moisture-vegetation interactions, multi-scale monitoring, and the integration of field measurements with Earth observation data are particularly encouraged.

Convener: Ágota Horel | Co-conveners: Tibor ZsigmondECSECS, Csilla Farkas, Zsófia Bakacsi
SSS8.2

The present context of accelerated changes in both climate and land use imposes an unprecedent pressure on a number of vulnerable ecosystems including wetlands, forests and rangelands, in which vegetation closely interacts and coevolves with soils and landforms. Complex interactions between climate, soils and biotic factors are involved in the development of landform-soil-vegetation feedbacks and play an important role in making ecosystems resilient to disturbances. In addition, large shifts in the distribution of vegetation and soils are associated with losses of ecosystem services (including carbon capture), frequently involving thresholds of ecosystem stability and nonlinear responses to both human and climatic pressures. This session will focus on ecogeomorphological and ecohydrological aspects of landscapes (including their connectivity), conservation of soil resources, and the restoration of ecosystem services and functions. We welcome theoretical, modelling, and empirical studies addressing the distribution of vegetation and coevolving soils and landforms, and particularly, contributions with a wide appreciation of the soil erosion-vegetation relationships that rule the formation of landscape-level spatial organization. We also welcome studies describing the implications of these spatial patterns of soils and vegetation for the resilience and stability of ecosystems under the pressure of climate change and/or human disturbances.

Convener: Patricia Saco | Co-conveners: Jose Rodriguez, Mariano Moreno de las Heras
SSS8.3

Biocrusts represent highly diverse communities formed by intimate associations between photoautotrophic organisms (i.e., cyanobacteria, algae, lichens, and bryophytes) and heterotrophic microorganisms inhabiting the uppermost millimeters of soil, where they form a thin, cohesive living layer. Although often overlooked, biocrusts cover nearly 12% of soils worldwide and play a pivotal role in regulating ecological processes that underpin ecosystem functioning and the provision of ecosystem services. Increasingly recognized as ecosystem engineers, biocrusts regulate the physical, chemical, and biological properties and processes of soils. Yet, their contribution to key ecosystem and Earth-system processes remains poorly quantified, and we still lack an integrated understanding of how processes operating at microbial and organismal scales scale up to influence ecosystem functioning and global change.
In this session, we invite contributions addressing the biodiversity, functioning, and ecological roles of biocrusts across spatial, temporal, and organizational scales, from microbial processes and organismal interactions to ecosystem and global processes. We welcome studies investigating biocrust effects on biogeochemical, carbon, nutrient, and water cycles; energy and surface–atmosphere exchanges; soil development, mineral weathering, erosion and dust emissions; geomorphological processes; biodiversity and species interactions; vegetation dynamics; and ecosystem stability, degradation, and restoration. We particularly encourage contributions exploring the responses, resilience, thresholds, and feedbacks of biocrusts under climate and other global changes, as well as their consequences for ecosystem functioning and large-scale environmental dynamics. Studies combining field and laboratory observations with experimental approaches, remote sensing, modelling, and other approaches to upscale biocrust processes across spatial and temporal scales are also encouraged.

Convener: Emilio Rodriguez-Caballero | Co-conveners: Dagmar Woebken, Ferran Garcia-Pichel, Bettina Weber
SSS8.4

Soils are central to terrestrial ecosystem functioning, supporting food production, biodiversity, water regulation, nutrient cycling, and climate resilience. They are also crucial for the health of connected freshwater and saline ecosystems. However, soils face multiple, compounding threats. These include increasing exposure to established and emerging contaminants, such as microplastics, alongside severe degradation from erosion, soil sealing, nutrient depletion, salinisation, biodiversity loss and climate-driven disturbances.
Addressing these challenges requires moving beyond linear approaches to soil management towards soil circularity. This concept focuses on restoring and reintegrating soil resources, nutrients, organic matter and biological functions into productive and natural systems.
This session addresses how frontiers in soil science and environmental technologies can support both the restoration of degraded soils and the prevention of further degradation. We specifically welcome research connecting soil processes with ecosystem interactions, circular resource use, and long-term resilience. A key focus is understanding how restoration and circular soil-management practices simultaneously impact multiple soil functions with different results and consequences for soil ecosystem services.
Contributions are encouraged on the co-benefits of nature-based solutions and regenerative approaches that enhance soil organic carbon (SOC) storage, nutrient availability, soil structure, biodiversity, water quality, crop productivity and ecosystem restoration. Furthermore, we welcome studies utilizing advanced monitoring, sensing, and predictive modelling to identify early signs of soil degradation and support preventive management. Emerging tools, such as proximal and remote sensing, spectroscopy, soil biodiversity indicators, machine learning, digital soil mapping, process-based modelling and integrated monitoring platforms are vital for shifting soil management from reactive remediation to proactive, adaptive intervention.


Dr. Saia research is funded by SHARInG-MeD (GA n 2211, PRIMA)
Dr. Marazuela research is funded by PACTOSAL (PID2024-160795OA-I00)
Dr. Lizaga research is funded by UPSTREAM (PID2024-162386OA-I00)

Convener: Laura Quijano | Co-conveners: Sergio Saia, Calogero Schillaci, Ivan LizagaECSECS, Miguel Angel Marazuela
SSS8.5

Soils are dynamic interfaces connecting the atmosphere, vegetation, surface water, and groundwater, and their physical and chemical properties strongly regulate water movement, contaminant transport, environmental processes, and ecosystem functioning. This session brings together experimental, modelling, remote sensing, and field-based approaches to investigate how soil-environment interactions across spatial and temporal scales affect ecosystems.
We welcome contributions addressing, but not limited to, soil hydraulic characterisation, soil structure and heterogeneity, soil amendment and treatment, and dynamic interactions between soil, water, and ecosystems. Studies integrating hydrological and environmental modelling, remote sensing, and GIS are particularly encouraged. The session aims to foster interdisciplinary understanding of how changes in soil properties and functioning influence water movement, environmental transport, and ecosystem processes.

Convener: Aparimita Priyadarshini NaikECSECS | Co-conveners: Geetanjali Das, Amrutha Suresh, Chandan Pradhan, Jacklin Jeke Nilling
SSS8.6

The last decades have been characterized by increasing climatic extremes and a foreshadowing of what is to come in a rapidly warming world. The disturbance of climatic extremes, such as droughts, floods, heatwaves and fires, to soil biogeochemistry and plant resilience has major consequences for the cycling of carbon and nutrients. Yet, the magnitude and direction of these responses differ strongly among soil types, climatic regions, and ecosystem settings.
The session aims to identify both common mechanisms and soil-specific responses to climatic extremes, and to better understand how short-term perturbations by such climatic extremes translate into long-term changes of soil systems. The session will bring together experimental, observational, and modelling studies that investigate specific fundamental biogeochemical mechanisms as well as soil development and soil functioning at larger scales. We welcome contributions that give a perspective on biogeochemical changes in plant-soil systems from all climate zones and both natural and managed soil systems.
Topics may include carbon and nutrient transformations, microbial and mineral controls on organic matter persistence, plant and rhizosphere shifts, nutrient mobilization and limitation, redox-driven processes, greenhouse-gas fluxes, and the legacy effects of climatic extremes and its effects on soil functioning.

Convener: Maya EngelECSECS | Co-conveners: Sebastian Doetterl, Marcus SchiedungECSECS, Carsten W. Mueller
SSS8.7

Soils play a crucial role in the functioning of terrestrial ecosystems, providing key ecosystem services such as carbon storage, water retention, nutrient cycling, biodiversity preservation, and protection against soil degradation processes (e.g., erosion, compaction, or fertility loss).

There is broad consensus that the implementation of management practices focused on soil conservation and restoration can help to improve soil functioning and resilience. The basis for building these resilience practices, lies halting the loss of soil carbon. For instance, agricultural practices such as no-till farming, cover crops, crop rotation and the use of compost. However, the dynamics of carbon change are a slow process in the medium and long term, which creates uncertainty in the short term. Furthermore, change sometimes begins with a negative response from the soil or with recommendations that have been proven in site-specific pedoclimatic contexts but cannot be scaled up to other contexts.

This raises the following question: how can science help to build confidence and reduce uncertainty whilst we await the anticipated changes in the medium and long term?

We strongly encourage submissions that include the evaluation of proven practices in operational contexts, ideas for communicating and sharing scientific knowledge, as well as access to useful data, user-friendly knowledge, tools and models to support decision-making, the valuation of ecosystem services, or resilient business models.

Acknowledgments: Project PID2023-146177OB-C22, funded by MICIU/AEI/10.13039/501100011033 and by the European Regional Development Fund (ERDF), European Union.

Convener: Elena Pareja-SerranoECSECS | Co-conveners: Iria Benavente-FerracesECSECS, Gema Guzmán
SSS8.8

Geotechnical and geo-environmental engineering are shifting toward sustainable, bio-driven solutions. Whether soil is transformed by living organisms, engineered by bio-inspired solutions, or built with earthen material, these approaches share a common thread: harnessing biological processes, bio-inspiration, and natural earthen materials for sustainable ground engineering and construction.

This session is built around two linked questions: how do biological and biomimetic agents interact with soil and earthen materials across scales, and how can we harness them from pore-scale processes to field- and structure-scale applications? [OdSJ(E1.1]We connect communities that rarely meet: researchers developing bio-inspired subsurface locomotion and self-burrowing robotics; those quantifying root and organism mechanics in soil; and those advancing bio-mediated and bio-based geo- and construction materials.

We welcome experimental, imaging-based, field, numerical, and sustainability assessment contributions, and strongly encourage Early Career Scientists.

Topics of interest include, but are not limited to:
- Bio-inspired subsurface locomotion & robotics: earthworm-, root-, and seed-inspired self-burrowing probes; peristaltic penetration and tip-extension burrowing in granular media; soft robotics and autonomous sensors for site characterisation; mechanics of the probe–soil interface.
- Root & organism biomechanics for geo-engineering: root growth forces, tip penetration, and directional growth; anchorage, root-induced soil deformation, bioturbation; root-based and bio-engineered slope stabilisation.
- Bio-mediated soil improvement: microbially and enzyme induced calcite precipitation (MICP, EICP), biopolymers, and bio-grouting for stabilisation, liquefaction mitigation, erosion /dust control; durability and pore-scale imaging (e.g. X-ray CT).
- Bio-stabilised earthen construction materials: raw-earth and stabilised-earth materials, biopolymer- and bio-cement-stabilised earth, and natural fibres, with their hygrothermal, durability, and life-cycle performance.
- Sustainability assessment: life cycle assessment (LCA), life cycle costs analysis (LCCA) and social LCA (S-LCA) of bio-treated soils and “low-carbon” geomaterials.

We especially encourage novel experimental setups, multi-scale imaging, field deployments, numerical modelling, and cross-disciplinary work linking soil mechanics, biology, robotics, materials, and sustainability assessment.

Convener: Floriana AnselmucciECSECS | Co-conveners: Fernando Patino-RamirezECSECS, Tomoya NagayamaECSECS, Magda PosaniECSECS, João Santos
HS8.3.2

Interactions between plants and their environment shape terrestrial fluxes, biochemical cycles, and agro-ecosystem productivity. However, we still lack detailed knowledge of how these interactions impact plant access to soil resources and, hence, plant growth, particularly under deficit conditions. The main challenge arises from the complexity inherent to biophysical and biochemical processes in soil and plants across multiple scales. To address these knowledge gaps, an improved understanding of soil-plant-related transfer processes is needed.

Quantitative approaches that integrate across disciplines and scales constitute stepping-stones to foster our understanding of fundamental biophysical processes at the interface between soil and plants. This session targets research investigating soil-plant-related resource transfer processes across different scales (from the rhizosphere to the global scale) and welcomes scientists from multiple disciplines encompassing soil and plant sciences across natural as well as agricultural systems. We are specifically inviting contributions on the following topics:

- Hot topics 2027: Heat and drought interactions, hybrid process-based and data-driven models
- Bridging the gap between biologically and physically oriented research in soil and plant sciences
- Measuring and modeling of soil-plant hydraulics and gas exchange, water, solute, and carbon fluxes through the soil-plant-atmosphere continuum across scales
- Identification of plant strategies to better access and use resources from the soil, including under abiotic stress(es)
- Experimental techniques such as non-invasive imaging and three-dimensional root system modeling tools
- Novel experimental and modeling techniques assessing belowground processes such as root growth, root water, and nutrient uptake, root exudation, microbial interactions, and soil aggregation
- Mechanistic understanding of plant water use and gas exchange regulation under drought and their implementation across scales (from cell to organ to single plant to agro- ecosystems, Earth system)

Co-organized by BG3/SSS8
Convener: Tina KöhlerECSECS | Co-conveners: Andrea Schnepf, Mohsen Zare
BG1.12 | PICO

Ecosystem respiration is a fundamental flux in the global carbon cycle, yet its full interpretation remains constrained by the incomplete consideration of the counterflow of atmospheric oxygen (O₂) into soils—the so-called "forgotten half" of the respiratory process. The respiration quotient (RQ = CO₂ produced / O₂ consumed) offers a unique, integrative signal that reflects not only microbial metabolic activity but also the interplay of biotic processes, abiotic gas transport, and redox dynamics across scales—from microbial communities to entire ecosystems. RQ values deviate in many cases from the simple expectations of RQ ~1.0, indicating the influence of diverse processes such as fermentation, nitrification, mineral weathering, and incomplete mixing.
Despite its potential, RQ remains underutilized in many fields of research from the microscale to large-scale ecological and atmospheric studies due to the technical challenges of high-precision O₂ measurements— which is necessary especially given the high atmospheric background (20.95%). To overcome this, we want to bring together people and ideas of different fields who try to tackle this challenge and answer questions related to the CO₂ - O₂ exchange of the living but also non-living environment.
We invite atmospheric scientists, microbial ecologists, and biogeochemists to join this emerging frontier: where the subtle interplay of CO₂ and O₂ fluxes reveals the hidden logic of ecosystem respiration—from the microscale of microbial metabolism to the macroscale of global carbon budgets. This session lays the foundation for a new generation of integrated, process-based monitoring networks that connect the biosphere’s breath to the atmosphere’s pulse.

Co-organized by SSS8, co-sponsored by GSA
Convener: Martin Maier | Co-conveners: Elad Levintal, Susan Trumbore, Timothy Gallagher
GM9.1

Glaciers cover roughly 10 percent of the Earth’s surface and help shape landscapes and relief in high latitude regions and many mountain ranges. Subglacial processes, such as sliding, create material that shapes the landscape. Debris that falls upon the ice, or is entrained in it, is advected down glacier to where it melts out, creating moraines. Existing sediment below the glacier can be mobilized by pressurized subglacial water and is then transported in proglacial rivers or deposited in lakes or fjords. Global glacial retreat is increasingly producing new ice-free areas in various geomorphological settings, from high-mountain valleys to coastal lowlands. The associated losses include decreased provision of meltwater in summer, reduced surface albedo and associated cooling effects, and in some cases increased natural hazards resulting from paraglacial geomorphic processes. However, there may be potential benefits, such as carbon storage in the vegetation, soil development and enlargement of pasture lands in now-exposed glacial sediments. An integrated, multi-disciplinary projection of the future properties and value of deglaciated valleys remains elusive but is necessary as we prepare for an uncertain future under climate change.

This session aims to improve understanding of glacier dynamics, surface processes, soil and plant development in glacial and deglaciating environments, and their interactions. We therefore invite contributions using experiments, modeling, laboratory, field observations and archives or remote sensing methods, or a combination thereof, that evaluate glacial processes, surface processes, soil development, ecological processes and their feedbacks. We welcome submissions that address these processes across a wide range of timescales, from sub-daily to multi-millennial, including those focused on these dynamics during past climate variations. Additionally, we are interested in studies that are focused on diverse glaciated environments from small alpine glaciers to ice sheets, improve methodology, are multidisciplinary or from previously understudied mountain regions – including in the global south. Research that addresses the changes that occur as climate warms and how these processes interact with other aspects of the Earth system, including glacier dynamics, is of particular interest for this session.
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Co-organized by CR4/SSS8
Convener: Arnaud Temme | Co-conveners: Jana Eichel, Anais Zimmer, Michele Freppaz
BG9.12

Drylands cover more than 40% of the Earth's land surface and support over two billion people. These ecosystems provide essential ecosystem services, sustain biodiversity, support food production and pastoral livelihoods, and play an important role in global biogeochemical and climate systems. However, many drylands are increasingly affected by interacting pressures including climate change, land degradation, biodiversity loss, unsustainable land use and resource extraction, leading to declining ecosystem resilience and increasing risks of ecological transition. Therefore, developing integrated tools for assessing and monitoring dryland ecosystems represents a high research priority.
Recent advances in Earth Observation (EO), including long-term satellite archives, hyperspectral sensors, SAR, LiDAR, UAVs and Artificial Intelligence (AI), are transforming our ability to understand dryland dynamics across spatial and temporal scales. These approaches are enabling improved monitoring of vegetation change, ecosystem functioning, degradation processes, restoration outcomes, biodiversity patterns and ecosystem resilience.
Particular attention is being given to the development of EO-based indicators of land degradation, ecosystem condition, ecological integrity, resilience loss and recovery. Emerging EO approaches are also improving our ability to monitor important dryland transition processes such as woody vegetation encroachment, or alterations in vegetation spatial patterns, all modifying the structure and functioning of rangelands, savannahs and shrublands across large regions of the world, with important consequences for ecosystem resilience, biodiversity, fire regimes, ecosystem services and pastoral livelihoods.
The increasing availability of very-high-resolution imagery and hyperspectral datasets is also creating new opportunities for monitoring key but often overlooked dryland components such as biological soil crusts (BSCs), whose influence on soil stability, nutrient cycling, hydrology and ecosystem functioning makes them critical indicators of dryland health, degradation status and ecosystem resilience.

Co-organized by SSS8
Convener: Elias Symeonakis | Co-conveners: Emilio Rodriguez-Caballero, Eva Arnau-Rosalén
BG10.1

This session will focus on Carbon dioxide removal (CDR) strategies that aim increase alkalinity along the land-to-ocean aquatic continuum. This includes addition to alkalinity to rivers (river alkalinity enhancement (RAE) or inland water alkalinity enhancement (IWAE) that sit at the intersection of two more established CDR pathways, terrestrial enhanced weathering (ERW) and ocean alkalinity enhancement. RAE/IWAE projects aim to achieve net removal of atmospheric CO₂ through accelerated mineral weathering and increased riverine alkalinity export to long-term ocean storage. but raises a distinct set of scientific and practical questions tied to the hydrology, biogeochemistry, and ecology of flowing and standing inland waters and estuaries.
This session invites contributions spanning the full pipeline from fundamental science to deployment, including:
• Safety and ecological risk thresholds for water quality and freshwater biota (fish, benthic invertebrates, periphyton) under alkalinity dosing,
• Scaling potential and site-selection criteria across river systems, lakes, and reservoirs,
• Cost and feedstock considerations for geochemical CDR at inland-water scale,
• Measurement, reporting, and verification (MRV) protocols, including direct field quantification and handling of CO₂ evasion at hydraulically complex sites (steps, falls, riffles),
• Ecological co-benefits, including interactions with freshwater acidification remediation,
• Case studies from active or pilot RAE/IWAE projects,
• Laboratory and mesocosm experiments isolating dissolution kinetics, evasion dynamics, and ecological response,
• Modelling of CDR potential, biogeochemical fate, and downstream/ocean carbon transport, and
• aqueous monitoring of terrestrially derived weathering products from ERW.
We welcome theoretical, observational, experimental, and modelling contributions, and particularly encourage early-career researchers and those working across disciplinary boundaries (hydrology, biogeochemistry, ecotoxicology, engineering).

Co-organized by HS13/SSS8
Convener: Shannon Sterling | Co-convener: Isaac Bahler

SSS9 – Soil, Forestry and Agriculture

Sub-Programme Group Scientific Officers: Rossano Ciampalini, Álvaro F. García-Rodríguez, Marcus Schiedung

SSS9.1

Soil degradation poses a critical threat to global environment, ecosystem services, and agricultural sustainability. Natural and agricultural systems are increasingly vulnerable to severe degradation processes—including desertification, soil erosion, salinisation, and chemical pollution—driven by the combined pressures of climate change and anthropogenic activity. Shifting precipitation regimes and rising average temperatures disrupt the soil water balance, intensifying water deficits, nutrient losses, and increasing soil salinity. Concurrently, unsustainable land management, deforestation, intensive cultivation, and the overapplication of agrochemicals accelerate physical and chemical disturbances that impair overall soil quality and biodiversity.
This session convenes research—from long-term field observation plots to advanced remote and proximal sensing—to systematically examine the mechanisms, impacts, and indicators of soil degradation, resistance, and resilience across diverse land uses and environmental contexts. We welcome contributions that quantify how land-use dynamics drive the depletion of critical soil functional properties and evaluate spatial and temporal trends in soil health.
In parallel, the session explores innovative, evidence-based soil conservation strategies designed to halt and reverse soil degradation. Key topics include sustainable management practices such as conservation agriculture, agroforestry, organic amendments, targeted erosion control, and soil salinity management. We place strong emphasis on how these practices restore soil structure, improve water retention, and foster biological activity, thereby enhancing ecosystem capacity to buffer extreme weather events. Finally, we highlight the integration of long-term observational data with policy frameworks and participatory stakeholder approaches. By bridging observational science with sustainable soil management, this session aims to advance available approaches for long-term soil conservation, agricultural productivity, and overall soil functionality.

Convener: Rossano Ciampalini | Co-conveners: Anna Andreetta, François Colin, Armand Crabit, Stéphane Follain
SSS9.2

Agrogeophysics applies geophysical methods such as electrical resistivity tomography, electromagnetic induction, ground-penetrating radar, seismic and other techniques, across platforms ranging from hand-held instruments and ground-based systems to drone- and satellite-borne sensors, to characterise spatial and temporal patterns and processes in the soil-water-plant continuum that are relevant for agronomic management. Being minimally invasive, spatially exhaustive, multi-scale and repeatable in time, these methods give access to information of states and processes in agroecosystems that conventional point-based monitoring cannot provide, and they are increasingly used to support sustainable, water-efficient and climate-resilient farming.
This session brings together contributions that monitor, map or model soil and plant properties and states of agronomic relevance, including texture and structure, salinity, compaction, water content and fluxes, rooting depth and root-zone dynamics, soil organic carbon, drainage and irrigation performance; develop and apply proximal or remote sensing approaches to soil-water-plant interactions; bridge the scale gap between laboratory, plot, field, farm and landscape; establish and test pedophysical relationships linking sensed properties to soil and plant variables of interest; fuse geophysical data with agronomic, soil sampling, remote sensing and yield data; integrate geophysical observations into hydrological, crop and root-water-uptake models, data assimilation schemes or digital twins; exploit machine learning and other data-driven tools for acquisition design, inversion, interpretation and upscaling.
We particularly welcome work on operational use in real farming systems, benchmark datasets and open data and software, uncertainty quantification, and the translation of geophysical information into decision support, advisory services and soil monitoring policy.

Convener: Alejandro Romero-RuizECSECS | Co-conveners: Agnese InnocentiECSECS, Lena LärmECSECS, João Narciso, Anja Klotzsche
SSS9.3

Soil health is fundamental to crop productivity, ecosystem vitality, water regulation, carbon storage, nutrient supply, and the resilience of terrestrial ecosystems to multiple stressors. Yet soils are increasingly exposed to dynamic pressures associated with climate change, including drought, heatwaves, flooding, rapid rewetting, and shifting seasonal patterns. These stressors can alter soil functioning gradually or abruptly, with consequences for biological activity, plant performance, soil structure, and the capacity of soils to resist and recover from disturbance. Because many of these responses are mediated by soil microorganisms and their interactions with plants and the soil matrix, understanding soil health under climate stress requires linking processes across scales and scientific domains – from microbial habitats to fields and landscapes.
This session aims to bring together research that advances the concept, assessment, and management of soil health in a changing and increasingly dynamic environment. We welcome contributions that address how soil health and soil multifunctionality respond to climatic variability and extremes, and how resilience can be understood, monitored, and sustained across spatial and temporal scales. Particular emphasis is placed on the role of soil biota, especially microorganisms, as drivers and indicators of soil health, as well as on plant-soil-microorganism interactions that shape resistance, recovery, and long-term functionality of soils.
We invite experimental, observational, and modelling studies that contribute to a more integrative understanding of soil health, including the development of indicators, resilience concepts, monitoring approaches, and management strategies. Topics may include soil health under climate extremes, biological indicators of soil functioning, plant-soil-microorganism interactions, recovery after disturbance, scaling from soil microsites to landscapes, and links between soil health, ecosystem services, and sustainable land use. Contributions that connect fundamental mechanisms with applied assessment and land management are especially encouraged.
By connecting perspectives from soil and plant sciences, microbiology and biogeochemistry to landscape-scale processes, this session will provide a platform to discuss how soil health can be defined, measured, and strengthened under the increasing pressures of global change.

Convener: Carsten W. Mueller | Co-conveners: Maren Dubbert, Nicolas Brüggemann, Klaus Koren
SSS9.4

This session offers an opportunity to present studies or professional works regarding irrigated agriculture, either with disciplinary or multidisciplinary approaches, to promote resilience at different spatial scales, mainly when water and soil are limiting factors. It explores scientific, technological, and managerial breakthroughs aimed at transforming irrigated agriculture in a changing climate in the following areas:
• Traditional, novel, and transitional technologies for irrigation management, control and practical application.
• Digital irrigation: application of satellite UAV, and thermal imaging for ET estimation, crop stress detection, and yield forecasting.
• Precision Irrigation: application of sensor networks, artificial intelligence, big data in irrigation scheduling.
• Clime adaptation: strategies for mitigating heatwaves, prolonged droughts, and soil salinization in irrigated systems.
• Safety in non-conventional water resources (treated wastewater, desalinated water, and brackish resources) in agricultural systems.
• Improving the integration of climate change scenarios and weather forecasts into agro-hydrological models and decision support systems to improve decisions in irrigation management and safe surface water-groundwater interactions.
• Water- Food-Energy-Ecosystem (WEFE) Nexus for evaluation of: energy footprint, carbon trade-offs, and environmental flows associated with modern irrigation systems.

Convener: Leonor Rodriguez-Sinobas | Co-conveners: Alejandro Pérez-Pastor, Moreno Toselli, Daniel Alberto Segovia-CardozoECSECS
SSS9.5

The availability of plant nutrients is governed by interacting chemical, physical, and biological processes within the soil–soil solution–plant continuum. Understanding these processes is essential for assessing soil fertility, optimising fertiliser requirements, and evaluating the environmental risks associated with nutrient losses and contamination. Conventional extraction methods used to estimate plant-available nutrient fractions often provide only a static snapshotof soil nutrient availability and may not deliver the level of accuracy and detail on soil fertility required for effective nutrient managemant in modern intensive agriculture aimed at achieving high crop yields. More accurate assessment of dynamic nutrient availability is equally important in organic farming, where crop nutrition depends strongly on the mobilisation and cycling of soil nutrient reserves.
This session will focus on the processes controlling the release of nutrients from the soil matrix into the soil solution, their sorption and desorption at soil particle surfaces, diffusion and transport, and subsequent uptake by plant roots. Contributions examining the effects of soil texture, pore structure, mineralogical composition, pH, and organic matter content on the mobility and bioavailability of phosphorus, potassium, magnesium, sulphur, and micronutrients are particularly encouraged.
The session will also address the release of mineral nutrients during organic matter decomposition. This includes microbial mineralisation, enzyme-mediated decomposition, rhizosphere processes, and the effects of root exudates on the cycling and availability of phosphorus, sulphur, and micronutrients.
We welcome laboratory and field studies, as well as experimental, theoretical, and modelling approaches. Contributions that integrate processes across the soil–soil solution–plant continuum, connect nutrient pools with fluxes and plant uptake, or develop improved approaches for assessing dynamic nutrient availability are especially encouraged.
By bringing together soil and plant scientists, biochemists, microbiologists modellers, this session will advance our understanding of nutrient dynamics within soils and nutrient transfer from soil to plants, thereby enabling more accurate assessments of soil nutrient status, fertiliser requirements, and associated environmental risks.

Convener: Tonu Tonutare | Co-conveners: Manfred Sager, Karin Kauer, Anna Gunina
SSS9.6

Wildfires are a global phenomenon with significant environmental, social, and economic impacts. These impacts are expected to intensify due to climate change, land abandonment, inadequate land management and planning factors that further drive land degradation and reduce the provision of ecosystem services.

This growing threat calls for urgent scientific attention to better understand the effects of wildfires on ecosystems and to develop integrated tools for land management before and after fires. Such efforts are essential for reducing vulnerability to wildfires and mitigating their impacts. However, this challenge extends beyond the scientific community, requiring the active involvement of stakeholders and policy-makers worldwide, as fundamental resources, such as water, soil, raw materials, and habitats, are at risk.

This session invites contributions from researchers studying the effects of wildfires on ecosystems, covering the full spectrum from prevention to post-fire recovery. We welcome laboratory, field, and modelling studies on the following topics:

i. Prescribed and/or experimental fires
ii. Fire severity and burn severity
iii. Fire effects on vegetation, soil, and water
iv. Post-fire hydrological and erosive responses
v. Post-fire management and mitigation
vi. Socio-economic aspects of pre- and post-fire land management
vii. Fire risk assessment and modelling

Convener: Carmen Sánchez-GarcíaECSECS | Co-conveners: Sarah Baker, Luis Filipe LopesECSECS, Antonio Girona-García, Diana Vieira
SSS9.7

Many political bodies set targets to promote specific land management practices. One of the most ambitious sustainability benchmarks in modern agriculture is the EU's Farm to Fork Strategy, which aims to increase the proportion of organic agricultural land to 25% by 2030. Organic farming and other promoted practices (e.g. agroecology, agroforestry and regenerative farming) aim to make soil and land use more sustainable while still allowing for the production of healthy food at competitive levels. These practices are also frequently associated with climate change mitigation and/or adaptation, as well as the promotion of soil fertility and biodiversity.

Crop and soil management practices are key drivers that affect soil and agroecosystem functioning, as well as ecosystem services such as food, fodder and fiber production. However, the long-term effects of specific management practices on soil properties (e.g. soil organic carbon and nutrient stocks, soil as a habitat for biota, or physical soil degradation), or agrobiodiversity-related indicators (e.g. the availability of feed for pollinators and wild flora that is beneficial for crops), are partly unknown and more difficult to assess.

This session invites contributions that study the effects of different crop and soil management practices, or land use options, on soil fertility, crop performance, the multifunctionality of agroecosystems, and floral and faunal agrobiodiversity. The session will facilitate interdisciplinary exchange between academia, agricultural practice, nature conservation, and society.

We particularly invite contributions focusing on the following:
> Organic farming
> Conservation agriculture, reduced or no tillage
> Regenerative farming
> Agroforestry
> Crop diversification
> Agroecology
> Ethnobotany
> Biodiversit

Convener: Klaus Jarosch | Co-conveners: Johanna Jacobi, Ixchel Hernández-Ochoa, Gabriele Gollner, Sabine Seidel
SSS9.8

The agri-environmental sciences offer endless possibilities for the application of Interpretable Machine Learning methods.These methods can aid in evaluating mechanistic assumptions or in revealing unforeseen connections between variables. Covering different spatial and temporal scales and linking between them, scientists have proposed and used a wide variety of IML models, each with their unique demands regarding data, statistical analysis and interpretation of results.
To gain an appreciation of this range, this session invites contributions involving interpretable Machine Learning and xAI applications in the agri-environmental and forestry sciences. The applied models may cover different a-priori assumptions, data requirements, spatial and temporal scales, and methods of statistical analysis. The rationale of their choice should be communicated clearly to give (early career) scientists methodological inspiration for their own pursuits.

Convener: Luca Giuliano Bernardini | Co-conveners: Eric SmitECSECS, Clara Rajadel Lambistos
SSS9.9

There is a demand to reduce greenhouse gas emissions and increase soil organic carbon in the agricultural sector to mitigate climate change. Further, there is an interest in improving soil health to improve productivity and resilience of crop- and grasslands. Different EU initiative/programs (e.g. GreenDeal; EU Soil strategy for 2030, 4 per mille, Soil Mission) underpin the relevance and political interest in these topics. Therefore, applicable solutions for agriculture are required to achieve one or some of these targets.
Due to the complexity and heterogeneity of the processes generic solution can have locally diverse impacts and optimum solution might differ based on local conditions. Clear advice for farmers requires an excellent data basis for impacts of management practices under diverse conditions and low uncertainty. Therefore, a better understanding about the impacts of smart agricultural solution in the field is required to improve the understanding of the variety of options.
The objective of the session is to provide an overview about available options to improve agriculture to mitigate climate change by reducing emissions or increasing soil organic carbon. Beside climate change mitigation, farmers have a major interest in improving soil health to increase the resilience of the system, improve the quality of the products or increase yield. Therefore, we invite applications for studies, which analyse management practice changes for climate change mitigation options, including their impacts to the wider agricultural system. This includes studies using field or laboratory measurements, or modelling, in croplands or grasslands, in organic or conventional systems. Studies that include multiple aspects of the agricultural system are of most interest, although studies that focus on one of these aspects are also welcome.

Convener: Matthias Kuhnert
SSS9.10

Agricultural systems are increasingly challenged to maintain soil health and ecosystem functioning while reducing external inputs, nutrient losses and environmental impacts. Integrated crop–livestock systems offer opportunities to reconnect nutrient and carbon flows between crops, plants, animals and soils, with livestock manures and other organic resources playing a central role in closing biogeochemical cycles. However, these systems also involve complex interactions and trade-offs affecting soil processes, nutrient availability, carbon dynamics, greenhouse gas emissions, biodiversity and the resilience of agroecosystems under global change.
This session invites contributions exploring the interactions between soils, plants and livestock across integrated and circular agroecosystems. We welcome studies addressing soil physical, chemical and biological processes; carbon and nutrient cycling; soil organic matter and soil health; manure and organic amendment dynamics; greenhouse gas emissions; microbial and soil biodiversity; and the effects of management on ecosystem functions and resilience.
We particularly encourage contributions that investigate how plant–livestock integration and circular management can support agroecological transitions, including approaches that reconnect livestock-derived nutrients with plant production and soil functioning across croplands, grasslands, pastures and mixed farming systems. Experimental, modelling and long-term observational studies are welcome, as well as research examining trade-offs, synergies and system-level outcomes under changing climate and management conditions.

Convener: Perrine FlorentECSECS | Co-conveners: Dorra Gharbi, Rene Baumont
SSS9.11

Agroforestry systems (AFS) – land-use systems in which woody perennials are deliberately integrated with crops and/or livestock on the same land-management unit, following a specific spatial arrangement or temporal sequence – are increasingly promoted as a Nature-Based Solution for resilient and climate-adapted agricultural systems. Through the synergistic interaction of trees and herbaceous components, AFS deliver a wide range of ecosystem services (ES), including provisioning, regulating, supporting, and cultural services. The latter are closely linked to traditional agricultural landscapes, some recognized as FAO GIAHS (Globally Important Agricultural Heritage Systems). Despite their well-documented benefits, the adoption and conservation of AFS remain challenged by rapid global change, including climate change, rural depopulation, agricultural intensification, and the erosion of traditional knowledge.
AFS are complex systems that are challenging to study and implement. Only a few models simulate their biophysical processes, and available approaches are often data-intensive or poorly suited to their intended purpose. Experimental studies are also difficult to generalize, as results often depend on highly site-specific conditions and interactions. This complexity creates ambiguity in the definition of AFS, hindering their recognition in agricultural and environmental legislation.

In this context, the session aims to bring together researchers and practitioners to advance hybrid knowledge on AFS worldwide and support their practical implementation. We welcome contributions that:
- Assess ES of AFS across different scales;
- Evaluate the vulnerability of AFS under current and future scenarios, and their potential to contribute to climate change mitigation and adaptation;
- Design innovative practices to improve the efficiency, productivity and sustainability of AFS;
- Investigate processes linked to the inclusion of trees in croplands and/or pastures through experimental or modelling approaches;
- Discuss barriers – technical, economic, governance-related – that hamper the successful implementation of AFS;
- Showcase transdisciplinary approaches involving stakeholder engagement and co-creation in AFS;
- Highlight understudied traditional AFS and the value of traditional ecological knowledge.

The session is organized within the Shared Innovations for Mediterranean Agroforestry Systems (SHARE) project, part of the PRIMA Programme supported by the EU.

Convener: Lorenzo VillaniECSECS | Co-conveners: Mohammed El HafyaniECSECS, Matteo Francioni, Jamila MsadekECSECS
SSS9.12

Soil management practices strive to balance outcomes across soils, climates, landscapes, or management histories. A management practice can enhance soil health, carbon storage, nutrient retention, or crop productivity in one context, but generate limited, neutral, or even undesirable soil changes in another. Understanding these context dependencies is therefore essential for determining when, where, and why management practices succeed.
This session focuses on the mechanisms, interactions, and boundary conditions that determine desirable soil management outcomes across spatial and temporal scales. We particularly welcome studies examining interactions among beneficial management practices, including cover crops, crop rotations, reduced tillage, residue management, and organic amendments, and their interactions with soil properties, landscape position, weather and climate extremes, and management legacies. We especially encourage multi-factor and mechanistic research addressing synergies and trade-offs among soil carbon and nitrogen dynamics, water availability and retention, soil health, greenhouse gas emissions, crop productivity, and ecosystem services.
By bringing together researchers across diverse fields including soil science, biogeochemistry, agronomy, ecology, and environmental sciences, this session aims to identify the drivers of when and where soil management delivers benefits and to support evidence-based, site-tailored strategies for sustainable agriculture.

Convener: Laura Van Eerd | Co-conveners: Roberto Calvelo-Pereira , Yajun PengECSECS
SSS9.13

Agriculture is pivotal in the European economy and the global food supply. Europe is a significant producer of diverse crops, contributing significantly to feeding the world's population. The quality and characteristics of agricultural products are closely linked to the specific environmental conditions in which they are grown. These environmental factors, including climate, soil, and water, can vary significantly across regions and are increasingly influenced by the challenges of climate change.
Understanding the spatial and temporal variability of environmental factors is crucial for managing and preserving agricultural landscapes and adapting to climate change's current and future impacts.
This requires a deep understanding of plants’ mechanisms for acclimation, keeping in mind that functional traits (e.g., phenology,etc.) can be indicators and proxies of plant status, plasticity and resilience. Moreover, it involves applied research and technological innovation in agriculture, including the use of sensors to monitor environmental variables, remote sensing and drones for crop monitoring, predictive models for yield and disease, and advanced methods to study nutrient cycles and soil health.
Furthermore, growing public awareness of the importance of ecosystem health and sustainability has led to adopting quantitative approaches to understand the link between agricultural practices and ecosystem services, which are crucial for achieving long-term environmental goals. Agroecological approaches, such as cover cropping, organic amendments, and integrated pest management, are being increasingly adopted to enhance biodiversity, soil health, water and nutrient retention, and resilience to climate change.
On these bases, the session will delve into:
- Quantifying and Spatially Modeling Environmental Factors: Examining the complex interplay of climate, soil, and water and their influence on plant growth, yield, and quality.
- Agricultural Resilience to Climate Change: Exploring the adaptability of agricultural systems in the face of a changing climate and identifying strategies for adaptation and mitigation.
- Sustainable Agricultural Practices and Ecosystem Services: Analyzing the impact of diverse agricultural practices on soil and water quality, biodiversity, and related ecosystem services.
- Precision Agriculture and Technological Innovation: Utilizing advanced technologies to optimize resource use, improve crop management, and enhance sustainability.

Convener: Antonello Bonfante | Co-conveners: Veronica De Micco, Alessandra Iannuzzi
BG8.6

Peatland restoration for conservation purposes has been implemented for decades now, but recently the focus has been shifting towards a reconciliation of the production of biomass with ecological goals, especially the reduction of greenhouse gas (GHG) emissions, while peatland management in conservation-focusses projects increasingly has to be adapted to climate change. Management measures include, but are not limited to, productive use of wet peatlands (paludiculture), improved water management in conventional agriculture and forestry, photovoltaic on wet peatlands, solutions for peat originating from infrastructure projects and innovative approaches in conservation-focused rewetting projects. We invite studies addressing all types of peatland management and their impacts on GHG exchange, ecosystem services and biodiversity. Work on all spatial scales from laboratory to global level addressing biogeochemical and biological aspects as well as experimental and modelling studies are welcome. Furthermore, we invite contributions addressing policy coherence e.g., in the context of the EU Nature Restoration Law and evaluating policy instruments for initiating and implementing new management practices on organic soils. Implementation and efficiency of management practices depends not only on hydrogeology and climate but also on other regional factors. Therefore, we hope to host contributions from different geographical regions where peatlands are important including boreal, temperate and tropical peatlands.

Co-organized by SSS9
Convener: Bärbel Tiemeyer | Co-conveners: Franziska Tanneberger, Łukasz KozubECSECS, Hanna Silvennoinen, Susan Page
BG5.1

Fire has emerged as a dominant driver of change in tropical forests. In Amazonia, understory fire and degradation now affect an area comparable to the area deforested. Severe and frequent droughts, combined with widespread degradation, have caused areas with little recent history of fire to burn. There remains large uncertainty in how much carbon is lost to degradation, the time for degraded forests to recover structure, diversity, and carbon, and the role of fire in changing soil carbon fractions, including charcoal.

Soil radiocarbon analyses and new approaches to estimate pyrogenic carbon provide baseline data spanning centuries to millennia to assess modern fire regimes. Burn experiments, burn chronosequences, and plot networks assessing long-term change provide key ground-based data. Satellite data and modelling enable regional assessment and scaling. Combining these approaches and data can help to address knowledge gaps and large uncertainties in tropical carbon budgets. This session spans field, laboratory, remote sensing and modelling research on fire regimes, pyrogenic carbon, degradation and carbon in tropical forests. We invite contributions on:

--Reconstruction of fire history from soil charcoal radiocarbon, stable isotopes, and phytoliths and what it reveals about Holocene/pre-Columbian baselines for fires burning today;
--Pyrogenic carbon production, drivers, stocks, and turnover, and its role in soil fertility and carbon balance;
--Secondary and burned forest structure, tree composition, carbon stocks/fluxes, and their recovery following degradation;
--Controls on where and how tropical forests burn, including fire severity and intensity, flammability, and microclimate, and early-warning and forecasting;
--Approaches including Earth observation, forest and soil carbon models, soil respiration, scaling plot data to regional scales and assessing uncertainty.

Interdisciplinary contributions, work spanning tropical regions, and studies linking data over past and contemporary disturbance are especially welcome. Presentations by early career scientists and researchers based in tropical countries are encouraged.

Co-organized by GI1/SSS9
Convener: Ted R. Feldpausch | Co-conveners: Plínio Barbosa de Camargo, Lidiany CarvalhoECSECS, Kees Jan van Groenigen
BG3.11

After carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) are among the most potent greenhouse gases (GHGs), exacerbating global warming. Their rapidly rising concentrations in the atmosphere require urgent action. Forest ecosystems play an important role in the exchange of GHGs with the atmosphere; however, their global role is still far from being understood. It has been shown that not only soils but also trees can emit and/or consume CH4 and N2O in forests. Trees contribute to ecosystem exchanges in various ways. They can uptake and transport soil-produced CH4 and N2O to the atmosphere; produce and consume both gases in situ in tree tissues; and modify carbon and nitrogen turnover in adjacent soils. However, the individual processes involved beyond net ecosystem GHG exchange remain unclear and seem to depend on various factors, including tree characteristics, tree species traits, forest ecosystem type, environmental variables, and seasons. Moreover, there are also other, but still rarely studied co-players in the forest GHG exchange, such as ground vegetation, cryptogamic covers, or water bodies in case of forested wetlands. Interactions between soil, plants, and the atmosphere play a crucial role in controlling the global budget of these gases.

Our session will link scientists studying the CH4 and N2O cycles in forest ecosystems under different climatic, hydrological and scale conditions. This is crucial for improving our understanding of CH4 and N2O exchange in these ecosystems. We welcome contributions on production and consumption processes and mechanisms in soils and plant/tree tissues, as well as gas transport processes within the soil-tree-atmosphere continuum. We highly encourage gas flux measurements from forest soils, cryptogams, ground vegetation, water bodies (in forested wetlands), tree stems, leaves, and canopies using chamber systems or integrated ecosystem approaches (e.g., flux towers with eddy covariance, satellites, or modelling). We also encourage methodological studies investigating CH₄ and N₂O exchange in forest ecosystems.

Solicited author:
Dr. Josep Barba (CREAF, Spain)

Co-organized by SSS9
Convener: Katerina Machacova | Co-conveners: Laëtitia Bréchet, Thomas SchindlerECSECS
HS8.3.4 EDI | PICO

Blue and green water management is vital for sustainable and resilient food systems around the world.
This is true not only in drylands, where any productive activity is deeply related to the understanding of soil hydrological behaviour, and irrigation and green water management are key for agroecosystems’ health (e.g. being a defence against desertification), but in every socio-ecological ecosystem.
Also temperate or humid climates are, in fact, increasingly subjected to variations in the hydrological cycle, as well as to water scarcity and/or mis-management. Improper practices, which are not able to cope with climate-induced threats, may contribute to soil degradation and depletion of the available water resource. For example, incorrect irrigation techniques may lead to soil and groundwater salinization, with dramatic fallout on agricultural productivity.
Irrigation expansion, and paradoxically -through complex socio-hydrological dynamics- also irrigation efficiency improvements, could lead to increasing water consumption and water scarcity conditions . On the other hand, the role of irrigation goes beyond the technological aspects: traditional irrigation is a cultural heritage, which is often structurally resilient, and which needs to be faced with an interdisciplinary approach involving humanities.

This session welcomes contributions with a specific focus on:
- The understanding of the soil hydrological behaviour and of the mass fluxes through the soil in both drylands and environments under actual or projected water stress conditions (e.g. water shortage and/or mis-management, compaction, salinization)
- The understanding of the sociohydrological dynamics linking irrigation, green water, and soil management
- The interaction between irrigation, soil hydrology (including deep drainage) and socio-economic impacts.
- The analysis of the bio-geo-physical and social dynamics related to rainfed and irrigated agriculture in both arid and non-arid areas and oases, including rainwater harvesting, and managed aquifer recharge systems
- The management of rangeland areas, including their restoration
- The management and conservation of traditional irrigation systems, including the provision of co-benefits and ecosystem services

This session is co—sponsored by the International Commission on Irrigation and Drainage (ICID - https://icid-ciid.org/home); and by the International Center for Agriculture Research in the Dry Areas (ICARDA - https://icarda.org/).

Co-organized by SSS9, co-sponsored by ICID and ICARDA
Convener: Marco Peli | Co-conveners: Mira Haddad, Luigi PiemonteseECSECS, Fatma Wassar, Giulio Castelli
HS10.4 EDI | PICO

Hydrology and soil science originated from water-management needs for ancient civilisation and agriculture, but since then have developed into many specialised disciplines. While irrigation and yield management remain prominent research topics, agricultural fields as soil-plant-atmosphere systems are rarely seen as an integrated hydrological system, despite the pressing challenges posed by intensifying climatic extremes, degrading soils and declining water resources.
This session therefore refocuses attention on agricultural fields as coupled soil-plant-atmosphere systems in which hydrological, biogeochemical and ecological processes interact. Interdisciplinary approaches are crucial to improve process understanding for enhancing agricultural practices and making agricultural landscapes more resilient.
Given the contrasting temporal and spatial legacies of the processes involved, we need to consider agricultural landscapes under change. How can we prospectively manage systems with different process turnover scales? Moreover, which system-stabilising processes exist to make the landscapes more resilient, not only through “isolated” measures such as retention basins or hedges, but by enhancing characteristics and properties across entire fields or landscapes (e.g. improving soil structure to increase infiltration capacities)?

We invite contributions investigating soil-plant-atmosphere interactions, water, carbon and nutrient cycling, crop responses to environmental stress, and other processes shaping agricultural landscapes across temporal and spatial scales.
We particularly encourage contributions addressing how fundamental process understanding can inform agricultural management practices and modelling approaches. It is important to us to strengthen the connection between different scales – for example, linking small-scale and/or short-term observations and large-scale and/or long-term system responses, and translating them into management strategies/practices and applications.

This session aims to foster exchange between fundamental and applied research, and discussion about transforming interdisciplinary collaboration to impactful solution prospects.

Co-organized by BG10/SSS9
Convener: Svenja HoffmeisterECSECS | Co-conveners: Conrad Jackisch, Pauline Seeburger, Claudia VoigtECSECS

SSS10 – Digital Soils

Sub-Programme Group Scientific Officers: Sara Cucchiaro, Eugenio Straffelini, Marijn van der Meij

SSS10.1

Observations are the cornerstone of understanding hydrological processes, providing data for model development and validation. However, integrating monitoring strategies and measurement tools with data analysis and modelling remains a major challenge in vadose zone hydrology. This session brings together experimentalists, modelers, and data scientists working on innovative approaches for observing and simulating vadose zone processes, with emphasis on observation–model links across scales, from laboratory and plot experiments to field, catchment, regional, and continental applications. Advances in remote sensing, high-performance computing, artificial intelligence, digital twins, and the Internet of Things offer new opportunities to address these challenges. Integrating observations and models can improve quantification of water and solute fluxes, characterization of soil hydraulic properties, process identification, and assessment of responses to environmental change, including droughts, heatwaves, land-use change, soil degradation, salinization, erosion, contamination, and agricultural and water-management practices, while reducing predictive uncertainty.
We welcome contributions addressing:
• Innovative observations and monitoring technologies: laboratory and field methods, sensor networks, remote and proximal sensing, geophysics, environmental tracers, and measurements of soil water, energy, solute fluxes, and soil physical, hydraulic, and biogeochemical properties.
• Multi-scale data integration and analytics: data fusion and assimilation, uncertainty analysis, artificial intelligence and machine learning, and analysis of large, heterogeneous, high-frequency datasets.
• Vadose zone modelling: process-based, data-driven, and hybrid approaches; parameterization and validation; inverse modelling; model–data integration; upscaling and downscaling; uncertainty quantification.
• Applications under environmental change: vadose zone responses to droughts, heatwaves, climate variability and change, land-use change, irrigation and agricultural management, soil degradation, salinization, erosion, contamination, and other natural or anthropogenic disturbances.
• Emerging challenges and research frontiers: digital twins, interoperable monitoring infrastructures, high-performance computing, cross-scale and cross-environment transferability, and new strategies for linking observations with predictive models.

Convener: Aurora GhirardelliECSECS | Co-conveners: Paolo Nasta, Sara KönigECSECS, Tiantian ZhouECSECS, Dominik BittnerECSECS
SSS10.2

Climate extremes and unsustainable development are increasingly disrupting soil and water dynamics. Heavy rainfall, prolonged droughts, and human pressures are reshaping water and sediment flows, accelerating land degradation, and threatening food and water security. Addressing these challenges requires continuous monitoring and innovative data integration across various spatial and temporal scales. In this context, sensing technologies offer unprecedented opportunities to monitor the Earth’s surface and understand its processes, especially when they're enhanced by Artificial Intelligence (AI) and advanced computational tools to enhance predictive capability and pattern recognition. These geodata-driven approaches can also support decision-making for diverse stakeholders, for example by helping smallholder farmers manage risk and build resilience.

This session invites contributions that push the boundaries of how we observe, measure, and monitor soil and/or soil-water dynamics. We are looking to showcase and discuss research that spans a wide range of scales, from local plots to global systems, and employs a variety of sensing techniques, from proximal sensors (i.e., in-field and machinery sensors) to remote sensing (i.e., UAVs, airborne systems, and satellites).

We also welcome studies that explore the fusion of diverse geospatial datasets (e.g., soil sensors, LiDAR, photogrammetry, and satellite imagery) to gain a more holistic, multi-scale understanding of these processes. This also includes research that uses sensed data as input for modelling and/or aim at predict future scenarios under changing conditions.

This session is open to, but not limited to, the following topics and application fields (e.g., agriculture, forestry, urban development, and mountain environments):
Advanced proximal sensing and ground-based monitoring
• Remote sensing, UAV, airborne, and satellite remote sensing of soil and water investigations
• Fusion and integration of multi-source geospatial data
• AI and machine learning for soil and water analysis
• Novel monitoring workflows, protocols, and open-source tools
• Linking sensing data with process-based or distributed models
• Critical evaluations of opportunities and limitations of emerging technologies
• Translating sensing and modeling into decision-support frameworks

Interdisciplinary contributions are more then welcome, as well as the participation of early career scientists (ECS).

Convener: Wendi WangECSECS | Co-conveners: Sara CucchiaroECSECS, Eugenio StraffeliniECSECS, Fangxin Chen, Longshan Zhao
SSS10.3

Spatial soil information is fundamental for environmental modelling and land management. Spatial representation (maps) of soil attributes (both laterally and vertically) and of soil-landscape processes are needed at a scale appropriate for environmental management. The challenge is to develop explicit, quantitative, and spatially realistic models of the soil-landscape continuum. Modern advances in soil sensing, geospatial technologies, and spatial statistics are enabling exciting opportunities to efficiently create more consistent, detailed, and accurate soil maps while providing information about the related uncertainty. The production of high-quality soil maps is a key issue because it enables stakeholders (e.g. farmers, planners, other scientists) to understand the variation of soils at the landscape, field, and sub-field scales. They can be used as input in environmental models, such as hydrological, climate or vegetation productivity (crop models) addressing the uncertainty in the soil layers and its impact in the environmental modelling. When the products of digital soil mapping are integrated within other environmental models it enables assessment and mapping of soil functions to support sustainable management. We welcome presentations that 1) demonstrate the implementation and use of digital soil maps in different disciplines such as agricultural (e.g. crops, food production) and environmental (e.g. element cycles, water, climate) modelling 2) advance the tools of digital soil mapping 3) investigate the philosophy and strategies of digital soil mapping at different scales and for different purposes. We also welcome contributions reporting the state of the art of soil property prediction from hyperspectral satellites, especially focusing on quantitative estimations making use of data-driven approaches such as machine learning, and physically based modelling or the integration of both.

Convener: Laura Poggio | Co-conveners: Madlene Nussbaum, Gábor Szatmári, Jack Hannam, Sarem NorouziECSECS
SSS10.4

Machine learning (ML) is increasingly used in soil science to predict soil properties, biogeochemical processes, water and solute transport, greenhouse gas emissions, and environmental risks across spatial and temporal scales. However, high predictive accuracy does not necessarily guarantee reliable scientific inference or robust extrapolation. Data leakage, inappropriate data splitting, limited representativeness of training data, poor uncertainty characterization, and a lack of process consistency can substantially undermine model reliability when ML is transferred across soils, sites, regions, or environmental conditions.

This session focuses on the development and application of trustworthy and process-informed machine learning for soil science. We aim to bring together researchers working at the interface of soil science, environmental modeling, hydrology, biogeochemistry, and artificial intelligence to discuss how domain knowledge and physical, chemical, and biological processes can be integrated with data-driven approaches.

We particularly welcome contributions addressing: (1) rigorous model evaluation and data-splitting strategies that match intended extrapolation targets; (2) data leakage, distribution shifts, domain adaptation, and cross-site or cross-region generalization; (3) uncertainty quantification, interpretability, explainability, and causal inference; (4) hybrid and process-informed ML integrating mechanistic models, physical constraints, or scientific knowledge; (5) physics-informed and theory-guided learning for soil processes; (6) multi-scale learning from laboratory experiments to field, regional, and global applications; and (7) reproducible benchmarks, open datasets, and emerging foundation-model approaches for soil and environmental sciences.

The session seeks to move soil ML beyond purely accuracy-driven prediction toward models that are scientifically consistent, interpretable, transferable, and trustworthy. We especially encourage studies that critically examine when and why machine-learning models succeed or fail, and how combining mechanistic understanding with modern AI can improve both prediction and scientific discovery in soil systems.

Convener: Fengxian ChenECSECS | Co-conveners: Liqiong Yang, Bin Zhou
CL5.4

Land surface processes play a crucial role in shaping Earth's climate system, mediating land-atmosphere interactions, and driving terrestrial water-carbon-energy feedbacks. Land Surface Models, as core components of Earth System Models (ESMs), influence climate projections in benchmarks such as the CMIP7. However, land hydrology and its interactions with other components of the Earth system (e.g. biosphere, biogeochemical cycles) remain poorly represented in most ESMs, potentially inducing erroneous responses to anthropogenic climate forcings at global to local scales and leading to misrepresentations of droughts and floods. For instance, ESMs do not represent the observed decline of groundwater levels in water-limited regions that threatens groundwater-dependent ecosystems and exacerbates drought persistence, thereby increasing the risk of ecosystem shifts and progressive desertification. This crosscutting session provides an open, interdisciplinary platform to bridge the gap between hydrologists, hydrogeologists, ecohydrologists, and climate modelers.

We invite observational, theoretical, and numerical modeling contributions that advance the integrated representation of hydrological, hydrogeological, biophysical, and ecosystem processes within land surface models across spatial and temporal scales. Key areas of focus include the representation of the soil-plant-atmosphere continuum, plant hydraulics, vegetation stress dynamics, and biosphere-mediated moisture recycling, alongside subsurface hydrogeology such as explicit groundwater-table dynamics, lateral flow, and deep aquifer linkages. Contributions addressing human-water-ecosystem interlinkages (e.g., groundwater abstraction, irrigation, land-use change), high-resolution ESM configurations, advanced observational networks, and emerging AI/machine learning techniques are also strongly encouraged.

The overarching aim of this session is to overcome historical disciplinary silos and establish a shared agenda across modeling communities. By aligning interdisciplinary priorities, addressing cross-scale parameterization challenges, and improving the evaluation of land-based mitigation and adaptation strategies, this session seeks to define future needs and collaborative opportunities for the next ESM generation.

Co-organized by BG9/GD4/HS13/SSS10
Convener: Simone GelsinariECSECS | Co-conveners: Gianpaolo Balsamo, Rosie Alice Fisher, Andrea Alessandri, Stefan Kollet
GI4.4

Thermal remote sensing is an increasingly established technique employing passive sensors to deriveEarth’s surface properties from the radiation emitted in the Thermal Infrared (TIR) domain. Its main focus is the thermal state of an object or surface, together with the associated surface temperature and emissivity. These properties are relevant across geological, environmental, climatic, agricultural, biological, and engineering applications.

Recent technological advances have driven the development of TIR remote sensing: satellite sensors and data infrastructure systems can now acquire and manage large volumes of high-fidelity TIR data at a wide range of spatial and temporal resolutions. Besides airborne and ground-based systems, Unmanned Aerial Systems (UAS) are increasingly used as versatile platforms that combine high spatial resolution with flexible temporal revisit. Together with a growing catalogue of current and upcoming missions, this makes it a timely moment to take stock of where the field stands.

This session addresses established and emerging research directions in TIR remote sensing and discusses the community's upcoming challenges. We welcome contributions on new frontiers, case studies, and data-integration analysis related to:

• Geosciences: volcanoes, hydrothermal systems, geothermal potential, mineral exploration, rare earths, cryosphere.

• Climate, Urban Systems, and Ecosystems: urban heat islands, global warming impacts, ecosystem stress, forest health, fire risk assessment, water management.

• Agriculture and Precision Farming: crop stress monitoring, irrigation management, soil analysis and pest/disease monitoring.

• Technological and Methodological Innovations: new sensors for satellite, airborne, UAS and in-situ platforms, multi-platform and/or multi-sensor data integration, Cal/Val activities.

• Data Processing and Infrastructure: approaches for managing and processing large TIR datasets, data fusion techniques, advanced algorithms for atmospheric correction and temperature and emissivity separation.

Multi-disciplinary studies and contributions from Early Career Scientists are especially welcome.

Invited Speaker: Sabine Chabrillat, Helmholtz Centre for Geosciences (GFZ).

Co-organized by CL5/CR6/GMPV12/PS7/SSS10
Convener: Andrea BaroneECSECS | Co-conveners: Francesco Rossi, Bastian SanderECSECS, Gala Avvisati, Jennifer AdamsECSECS
GI2.3

The radioactive materials are known as polluting materials that are hazardous for human society, but are also ideal markers in understanding dynamics and physical/chemical/biological reactions chains in the environment. Therefore, man-made radioactive contamination involves regional and global transport and local reactions of radioactive materials through atmosphere, soil and water system, ocean, and organic ecosystem, and its relations with human and non-human biota. The topic also involves hazard prediction, risk assessment, nowcast, and countermeasures, which is now urgent important for the nuclear power plants in Ukraine, the Middle East, etc.

By combining long monitoring data (> halftime of Cesium 137 after the Chornobyl Accident in 1986, 16 years after the Fukushima Accident in 2011, and other events), we can improve our knowledgebase on the environmental behavior of radioactive materials and its environmental/biological impact. This should lead to improved monitoring systems in the future including emergency response systems, acute sampling/measurement methodology, and remediation schemes for any future nuclear accidents. Furthermore, the discharge of ALPS-treated water into the ocean, carried out as part of the decommissioning of the Fukushima Daiichi Nuclear Power Station, has attracted international attention and demonstrated that decommissioning a nuclear power plant that has suffered an accident requires a fundamentally different approach from that of a conventional decommissioning. Studies on past nuclear contamination events and other environmental radioactivity datasets are also welcome.

The following specific topics have traditionally been discussed:
(a) Atmospheric Science (emissions, transport, deposition, pollution);
(b) Hydrology (transport in surface and ground water system, soil-water interactions);
(c) Oceanology (transport, bio-system interaction);
(d) Soil System (transport, chemical interaction, transfer to organic system);
(e) Forestry;
(f) Natural Hazards (warning systems, health risk assessments, geophysical variability);
(g) Measurement Techniques (instrumentation, multipoint data measurements);
(h) Ecosystems (migration/decay of radionuclides).

Co-organized by AS4/BG10/ESSI4/HS13/SSS10
Convener: Daisuke Tsumune | Co-conveners: Roman Bezhenar, Tomoko Ohta, Yu Chiang, Masatoshi Yamauchi
HS1.6 EDI

Nature-based Solutions (NbS) are increasingly promoted as a key strategy for climate adaptation, aiming to improve sponge functioning by intercepting, slowing, storing, and slowly releasing water. By reducing flood peaks, enhancing drought resilience, and delivering ecosystem services such as improved water quality and biodiversity, NbS are central to climate-resilient land and water management. However, implementation at scale remains limited due to insufficient evidence on the (eco-)hydrological impacts of NbS across spatial and temporal scales, and limited translation of this knowledge into decision-making.
Key questions remain regarding how effectiveness evolves over time, how maintenance influences long-term outcomes, how impacts propagate across scales, under which conditions local interventions contribute to landscape-scale resilience, and how scientific evidence can support upscaling.
This session explores the role of quantitative assessment in understanding Nature-based Solutions (NbS) and supporting their upscaling. It examines how evidence from local monitoring and modelling to catchment-scale assessments can guide implementation, inform policy, and strengthen confidence in climate adaptation investments, advancing climate-resilient sponge landscapes. We welcome contributions that:
•Quantify the effectiveness of NbS for multiple objectives, including flood mitigation, drought resilience, and associated co-benefits, trade-offs, and uncertainties to inform design, implementation, prioritization, and upscaling.
•Investigate temporal and spatial scaling, including long-term performance, delayed benefits, degradation processes, maintenance requirements, and cumulative impacts from plot to catchment scales.
•Integrate monitoring, experimental, and modelling approaches to strengthen attribution, process understanding, and impact assessment of NbS, using observed evidence to validate models and evaluate the scaling of flood, drought, and eco-hydrological benefits.
•Highlight the qualitative and quantitative evidence required by local actors, implementers, policy-makers, and investors to support decision-making.
•Develop decision-support tools, indicators, and assessment frameworks that strengthen links between quantification, implementation, governance, financing, and policy.
•Demonstrate how evidence from monitoring and modelling has informed planning, policy development, implementation strategies, investment priorities, and the mainstreaming of NbS.

Co-organized by SSS10
Convener: Christopher WittmannECSECS | Co-conveners: Alejandro Dussaillant, Neeraj SahECSECS, Katarina Zabret, Mark Wilkinson
HS9.3

Quantitative information on the spatial patterns of soil redistribution during storms and on the sources supplying sediment to rivers is essential for advancing our understanding of the processes that control sediment transfer and for designing effective management strategies. It is also crucial to quantify sediment residence times and to reconstruct changes in sediment sources across a range of temporal scales. These needs are becoming increasingly urgent in light of intensified climate- and land use-driven impacts on erosion, sediment delivery, and sediment-related pollution affecting freshwater and marine environments. Over recent decades, sediment tracing (or fingerprinting) techniques, used alone or in combination with other approaches (including soil erosion modelling and sediment budgeting), have provided valuable insights to understand sediment source dynamics. Yet, their widespread application remains constrained by several methodological and conceptual challenges that the research community should address. We welcome contributions that address any of the following aspects:
• Developments of innovative field measurement and sediment sampling techniques;
• Advances in the accuracy and robustness of soil and sediment tracing techniques for quantifying soil erosion and redistribution;
• Sediment source tracing studies using conventional (e.g. elemental/isotopic geochemistry, fallout radionuclides, organic matter) or alternative (e.g. colour, infrared, hyperspectral, particle morphometry, eDNA) properties including methodological developments;
• Investigation of particle-bound contaminant transfers in catchments and river systems using sediment tracing techniques;
• Investigations of the current limitations in sediment tracing studies (e.g. tracer selection, tracer conservativeness, uncertainty analysis, particle size and organic matter corrections);
• Applications of radioisotope tracers to quantify sediment transit times over a broad range of timescales (from the flood to the century);
• Association of conventional techniques with remote sensing and emerging technologies (e.g. LiDAR, satellite);
• Cross-regional and multi-scale applications of tracing techniques to establish generic characterisations of source contributions;
• Integrated approaches to developing catchment sediment budgets: combining different measurement techniques, monitoring, and/or models to improve our understanding of sediment delivery processes.

Co-organized by SSS10
Convener: Olivier EvrardECSECS | Co-conveners: Núria Martínez-Carreras, Leticia Gaspar, Thomas Chalaux-ClergueECSECS, Thomas Hoffmann
CL4.29

Why do past climatic changes produce different societal outcomes across regions and through time? This session focuses on the pathways and feedbacks linking climate change, water availability, ecosystem productivity, resource landscapes, human agency, and societal changes during the Holocene and beyond. We invite empirical, theoretical, and modelling studies that identify these processes across past and present human-environment systems. Of particular interest are studies that integrate palaeoclimate and environmental records with archaeological, historical, or societal evidence; examine thresholds, feedbacks, and nonlinear responses; or use process-based, agent-based, network, complex-systems, and data-driven approaches to connect environmental forcing with human decision-making and societal change. By bridging together climate, environmental, and social perspectives, this session aims to advance a process-based understanding of why climatic changes produce diverse societal trajectories under different environmental and social context.

Co-organized by GM4/HS13/SSS10
Convener: Yumeng QuECSECS | Co-conveners: Hsun-Ming Hu, Annika Vogel, Yanzhen Li, Ashish Sinha
BG6.1

Despite methodological advances in functional microbial ecology, integrating this wealth of data into microbial biogeochemical models remains challenging. Data such as omics, stable isotope probing (SIP), and activity measurements can improve our fundamental understanding of biogeochemical cycles, and consequently increase model realism, and reduce uncertainty in model predictions, especially under scenarios of global change. Yet, a substantial knowledge gap remains in how this integration could be achieved. How can models invoke mechanisms that can be interrogated experimentally? What information can realistically be integrated and how much improvement can we expect? At the same time, how can we leverage model-generated hypotheses to design novel experiments to advance empirical ecology and theory?
This session aims to bring together empirical microbial studies and process-based modeling to close this gap. We welcome contributions using omics, SIP, activity-based approaches, and other methods targeting microbial functional traits, as well as modeling studies applying trait-based parameterization, genome-scale metabolic models, machine-learning-based trait inference, or data assimilation. We are particularly interested in how quantitative microbial traits that determine rates of biogeochemical cycling can be extracted from measurements to define functional groups that inform trait-based models. We envision presentations covering these topics in any biogeochemical context-from soils to sediments, from wetlands to oceans.

Co-organized by SSS10
Convener: Jonathan DonhauserECSECS | Co-conveners: Luciana Chavez RodriguezECSECS, Stefano Manzoni, Xingguo HanECSECS, Johannes Rousk
HS8.1.1

Multiphase flows play a central role in a broad range of natural and engineered processes, such as nutrient cycles and contaminant remediation in soils, and geological storage of carbon dioxide and hydrogen in deep reservoirs. Understanding multiphase systems across scales is therefore fundamental for water resources management as well energy and climate concerns.

The presence of multiple fluid phases enhances heterogeneity at the level of flow, mixing, and reaction in structurally heterogeneous media. This impacts the transport of dissolved substances and fundamentally changes mixing patterns and effective reaction rates, posing major challenges for predictive modeling. Recent theoretical and experimental advances provide unprecedented insights into the pore-scale mechanisms governing these processes and open new opportunities to tackle these challenges.

This session aims to bring together researchers working on fundamental and applied aspects of flow, transport, mixing, and reaction in multi-phase systems across scales. In particular, we encourage submissions relating to experimental, numerical, and theoretical contributions pertaining to the following topics:

- Impact of medium heterogeneity on multiphase flow, from the pore to the continuum scale.
- Impact of multiphase flow patterns on mixing and reaction rates across scales in heterogeneous media.
- Biogeochemical processes in multiphase systems.
- Applications to vadose zone hydrology and geological storage.

Co-organized by ERE3/SSS10
Convener: Juan J. Hidalgo | Co-conveners: Insa Neuweiler, Tomas Aquino
GM5.2

Landscape evolution models (LEMs) have matured into powerful and widely used tools in the geomorphologist’s toolbox. Increasingly robust representations of weathering, erosion, sediment transport and hillslope processes allow LEMs to function as digital laboratories in which hypotheses about landscape dynamics can be explored across spatial and especially temporal scales that are impossible to directly observe.
LEMs have been used to investigate a wide range of questions, including the response of landscapes to climate and tectonic forcing; river incision and sediment transport; hillslope evolution and landslide dynamics; glacial and periglacial processes; soil formation and weathering; drainage-network development; interactions between geomorphic processes and ecosystems; and the propagation of disturbances through coupled Earth-surface systems. Their ability to represent interacting processes also offers opportunities to explore cascading natural hazards, from landslide–river interactions to chains of sediment, flooding and slope instability, making LEMs increasingly relevant to a key societal concern.
At the same time, the field is entering an exciting period of methodological tension. As process-based models, LEMs seek to encode physical mechanisms and study their emerging interactions explicitly, while AI and data-driven approaches offer powerful alternatives for identifying patterns and emulating processes. Rather than treating these approaches as competing paradigms, this tension raises fundamental questions about what we expect models to represent, how we evaluate them, and how process understanding can be combined with emerging computational methods.
This session welcomes contributions from researchers who use, modify, or develop landscape evolution models, as well as those whose research questions could benefit from the application of LEMs.

Co-organized by NP8/SSS10
Convener: Alessia GiarolaECSECS | Co-conveners: Benjamin Campforts, Tom Coulthard, Wolfgang Schwanghart, Arnaud Temme
HS10.19

Water may be present in soil, groundwater or surface storage yet remain inaccessible because it is hydraulically disconnected, too saline, too tightly retained, or stored on timescales mismatched with biological or human demand. We define water accessibility as the capacity of stored water to enter ecologically or societally relevant fluxes, with that capacity varying with hydrological state, connectivity, salinity, biological demand and human intervention.
This session asks when, where, for whom and for how long stored water becomes accessible in human-modified critical zones. We welcome studies of mobile and less-mobile domains, preferential flow, soil hydraulic structure, root access, groundwater depth, salinity, wetting-drying transitions, irrigation, drainage, pumping, land-use change, restoration, hydrological memory, water age and transit times.
Contributions may use field or laboratory experiments, stable isotopes and other tracers, geophysics, remote sensing, water-age and transit-time analyses, and a broad range of modelling approaches. We encourage studies addressing accessibility and functional outcomes for transpiration, recharge, runoff, ecological resilience, crop production, water security and other major ecohydrological or societal fluxes.
We particularly encourage work from agricultural systems, wetlands, deltas, drylands, forests, restored landscapes and other human-modified critical zones. Comparative and negative-result studies are welcome, including cases where connectivity or tracer contrasts strengthen, collapse or shift with hydrological state. The aim is to identify measurable indicators, thresholds, trade-offs and management timing while avoiding the assumption that more stored water necessarily means more accessible water.

Co-organized by BG4/SSS10
Convener: Ying Zhao | Co-conveners: Jan Seibert, Bruce Dudley, Jesse Radolinski, Tiantian ZhouECSECS
HS6.10

Agriculture is the largest consumer of water worldwide and at the same time irrigation is a sector where huge differences between modern technology and traditional practices do exist. Furthermore, reliable and organized data about water withdrawals for agricultural purposes are generally lacking worldwide, thus making irrigation the missing variable to close the water budget over anthropized basins. As a result, building systems for improving water use efficiency in agriculture is not an easy task, even though it is an immediate requirement of human society for sustaining the global food security, rationally managing the resource and reducing causes of poverties, migrations and conflicts among states, which depend on trans-boundary river basins. Climate changes and increasing human pressure together with traditional wasteful irrigation practices are enhancing the conflictual problems in water use also in countries traditionally rich in water. Hence, saving irrigation water improving irrigation efficiency on large areas with modern techniques is an urgent action to do. In fact, it is well known that agriculture uses large volumes of water with low irrigation efficiency, accounting in Europe for around 24% of the total water use, with peak of 80% in the Southern Mediterranean part and may reach the same percentage in Mediterranean non-EU countries. North Africa region has the lowest per-capita freshwater resource availability among all Regions of the world.
Several studies have recently explored the possibility of monitoring irrigation dynamics and by optimizing irrigation water management to achieve precision farming exploiting remote sensing information combined with ground data and/or water balance modelling.
In this session, we will focus on: the use of remote sensing data to estimate irrigation volumes and timing; management of irrigation using hydrological modeling combined with satellite data; improving irrigation water use efficiency based on remote sensing vegetation indices, hydrological modeling, satellite soil moisture or land surface temperature data; precision farming with high resolution satellite data or drones; farm and irrigation district irrigation management; improving the performance of irrigation schemes; estimates of irrigation water requirements from ground and satellite data; ICT tools for real-time irrigation management with remote sensing and ground data coupled with hydrological modelling.

Co-organized by SSS10
Convener: Chiara Corbari | Co-conveners: Jacopo DariECSECS, Pierre LaluetECSECS, Timothy Foster

SSS11 – Material and Methods in Soil Sciences

Sub-Programme Group Scientific Officers: Yang Yu, Iria Benavente-Ferraces

SSS11.1

Recent advances in sensing, machine learning and process modeling have expanded on what is possible within Pedometrics, a branch of research at the interface of soil science and data science. However, many methodological challenges remain. This session focuses on methodological advances that improve the reliability, reproducibility and pedological soundness of digital soil mapping, spectroscopy and spectral transfer functions, pedo-transfer functions or other predictive statistical applications in soil science. We specifically invite contributions that address the underlying statistical, computational and conceptual tools needed to
1) produce pedologically consistent multi-property, multi-depth, multi-timepoint soil maps,
2) create suitable sampling designs for current state-of-the-art mapping approaches,
3) provide physically or chemically meaningful pedo-transfer functions,
4) quantify and propagate uncertainty in space–time and for multivariate outcomes,
5) provide methods for up- and downscaling (change-of-support) and realistic aggregation of uncertainties,
6) contribute to explainable machine learning and robust soil science-informed model diagnostics, and
7) integrate mechanistic soil process knowledge with data-driven algorithms into so-called hybrid approaches or soil science informed machine learning.
The session welcomes contributions that develop, compare, or benchmark novel approaches or present (open) software implementations that strengthen the foundations of pedometrics and enable robust and reproducible frameworks. We welcome developments towards all kinds of applications such as global to local soil health monitoring, soil function assessments or for farm level and forest management. The session aims to bring together statisticians, process modelers, computer scientists and pedologists to discuss methodological solutions that are general, reproducible and transferable across regions and applications.

Convener: Madlene Nussbaum | Co-conveners: Sarem NorouziECSECS, Lei Zhang, Gábor Szatmári, Laura Poggio
SSS11.2

Since the early days of soil science, protocols for fractioning of soil organic matter exist to better understand and describe the composition or turnover in soils. This remains a hotly debated topic, largely due to the persistent challenge of achieving meaningful measurements of soil carbon quality to better capture the persistence and vulnerability of carbon in soils. Unlike other soil parameters that are comparatively more straightforward to measure, the mechanisms conferring the persistence of soil organic matter in soils are far harder to isolate and quantify, and no single method will and can capture all of them simultaneously. Chemistry, density, size, thermal stability and many more intrinsic properties are used to separate soil carbon in operationally defined pools to be able to understand its (potential) persistence or functioning. For instance, by size and mechanical stability fractionation, aggregates and very stable pseudosands can be obtained for further analysis of physically protected organic matter. Moreover, a plethora of chemical and physical fractionation schemes exist to extract microbial or fungal parts to estimate their biomass, or density fractionation is applied to soils to separate particulate and mineral-associated organic matter. Despite a methodological diversity, a persistent difficulty lies in reconciling operationally defined fractions shaped by the extraction method itself with functionally meaningful, biologically or biogeochemically relevant pools in soil.
This session invites contributions focussing on methods to fractionate soil carbon in functional pools, from highly sophisticated, to novel or classical methods . We particularly welcome efforts to link laboratory-based fractions to computational modelling frameworks. Contributions that go beyond successful stories are especially encouraged: we invite submissions that reflect on fractioning not yielding the expected trends, and the exploration of the reasons behind this lacking link.

Convener: Jeroen ZethofECSECS | Co-conveners: Steven de GoedeECSECS, Simone Kilian SalasECSECS, Hermann Jungkunst
SSS11.3

Effective management of soil and water resources is fundamental to sustainable development, ecosystem resilience, and human well-being. Connectivity provides a powerful framework for understanding the transfer of water, sediment, nutrients, and associated materials across heterogeneous landscapes and their responses to climate variability, extreme events, land-use change, and human interventions. In particular, hydrological and sediment connectivity link landscape structure with hydro-geomorphic processes and provide an important basis for understanding watershed responses to environmental change.
Recent advances in field monitoring, remote sensing, geomorphometric analysis, process-based modelling, and data-driven approaches have improved our ability to quantify connectivity across spatial and temporal scales. However, challenges remain in translating connectivity assessment into process understanding, predictive capability, and effective management. Key questions include where and when critical source–pathway–sink linkages emerge, how connectivity changes under natural and anthropogenic disturbances, and how interventions can enhance desirable connectivity or promote strategic disconnectivity.
This session invites studies developing and applying connectivity-based approaches for sustainable watershed management. We welcome contributions addressing hydrological, sediment, geomorphic, and related ecological connectivity using field observations, experiments, remote sensing, geomorphometric indices, process-based models, and data-driven or machine-learning approaches. Studies focusing on temporal dynamics, cross-scale interactions, extreme events, land-use and climate change, and structural–functional connectivity are particularly encouraged.
The session also promotes the application of connectivity concepts to nature-based solutions and watershed restoration, including vegetation restoration, riparian management, and soil and water conservation measures. By bridging process understanding, monitoring, prediction, and management, we aim to clarify where, when, and how connectivity can be managed to reduce soil erosion and sediment-related risks, enhance watershed resilience, and support sustainable soil and water resource management.

Convener: Yang Yu | Co-conveners: Shouhong ZhangECSECS, Boško Blagojević, Stefano Crema, Marco Cavalli
GI4.6

This session aims at presenting current and forthcoming novel uses of spaceborne hyperspectral imagery acquired over several scales, especially the EnMAP mission, for geosciences and environmental applications. EnMAP provides high quality spectral data at 30 m spatial resolution covering the visible, near- and shortwave infrared regions with nearly global coverage and some regional time-series achieved after 5 years in orbit. Abstracts are solicited toward the characterization and quantification of geo- and bio-physical surface properties related to but not limited to soil and soil health, soil pollution, plastics, critical metals and minerals detection, carbon content in soils, hazards, volcanology, snow and ice properties, as well as vegetation, marine and atmospheric studies.

Co-organized by SSS11
Convener: Sabine Chabrillat | Co-conveners: Gabor Kereszturi, Emmanuelle Vaudour, Eyal Ben-Dor
GS4.3

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". Handling mistakes and setbacks is therefore 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 scientific publication if it confirms an accepted theory or 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.

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. In the spirit of open science and in an interdisciplinary setting, we want to bring the BUGS out of the drawers and into the spotlight. 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.

In a friendly atmosphere, we will learn from each other’s mistakes, understand the impact of errors and abandoned paths on our work, give each other ideas for shared problems, 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.

For inspiration, see the collection of BUGS - ranging from clay bricks to atmospheric temperature extremes - at https://meetingorganizer.copernicus.org/EGU25/session/52496

Co-organized by AS5/BG1/CR6/ERE7/ESSI1/G7/GD5/GI1/GM1/GMPV1/HS13/NP1/PS7/SM9/SSS11/TS10
Convener: Jonas PyschikECSECS | Co-conveners: Ulrike ProskeECSECS, Martin GauchECSECS, Justine BergECSECS, Florina Roana SchalamonECSECS
GM2.6

Imaging the Earth’s surface and reconstructing its topography to study the landscape and (sub-)surface processes have advanced rapidly over the past two decades, sometimes separately within different geoscientific disciplines. Developments in satellite, airborne, uncrewed aerial vehicle (UAV), and ground-based sensing, alongside advances in photogrammetry, Structure-from-Motion (SfM), LiDAR, computer vision, and automated processing, have transformed our ability to reconstruct and monitor the Earth’s surface in 2D, 3D, and 4D (time series).
The spatial, temporal, and spectral resolutions of current measurements offer the opportunity to study the surface evolution from local to regional scale at unprecedented detail. Equipped with optimized workflows, either digitizing analogue data, such as historical aerial photographs, or processing near-continuous records of topographic change, geoscientists now have a variety of tools to better understand our rapidly changing environment and disentangle anthropogenic from natural drivers.
Yet, challenges still exist at both methodological and application levels. How can reliable data be acquired in harsh, remote, or non-ideal environments? How can observations from different time periods, scales, and platforms be reconstructed, co-registered, and compared? How should measurement precision, systematic errors, and uncertainty be quantified and propagated into estimates of surface change? And how can computer-vision, machine-learning, and automation extract meaningful information from large and complex 3D and 4D datasets?
In this session, we invite contributions from across the geosciences (e.g., geomorphology, glaciology, volcanology, hydrology, soil sciences) on the opportunities, limitations, and challenges of surface imaging, topographic reconstruction, and change analysis across diverse environments.
We especially welcome contributions addressing (1) novel data acquisition in complex, remote, or rapidly changing environments; (2) image and point-cloud processing, including image matching, reconstruction, co-registration, and correction of sensor distortions; (3) precision and uncertainty assessment, including systematic errors; (4) construction and analysis of multitemporal and 4D datasets, from historical records to high-frequency and near-continuous observations; (5) automated processing, analysis, and information extraction from large and complex datasets; and (6) innovative applications in geosciences.

Co-organized by BG9/CR6/GI1/SSS11
Convener: Reuma AravECSECS | Co-conveners: Friedrich Knuth, Anette Eltner, Felix DahleECSECS, Livia Piermattei

SSS12 – Soil Policy and Legislation

Sub-Programme Group Scientific Officers: Laura Quijano, Laura Gismero Rodríguez

SSS12.1

Soil health is an active priority within the policy landscape of Europe. The EU Soil Strategy and the EU Soil Monitoring and Resilience Directive (SMD) have real potential to support changes in soil health for forest, agricultural and urban land-uses, especially if they are effectively informed by scientific evidence. Yet the translation of soil knowledge to be simultaneously actionable, evidence-based and context-relevant across spatial and temporal scales is a non-trivial task, both with respect to process and content. This session is hosted by members of the PSOILICY project (connecting soil science and policy through national hubs, policy labs and tools for evidence-based soil governance) and invites contributions from researchers working on soil health within the science-policy interface. Presentations highlighting mechanisms for policy support, examples of soil knowledge translation, frameworks or platforms for providing policy-relevant soil knowledge, as well as digital, data-driven and AI-enabled approaches for integrating, interpreting and delivering soil knowledge for policy use, are welcome. Presentations addressing the communication of scientific uncertainty in policy are particularly encouraged.

Convener: Amanda Matson | Co-conveners: Marion Bardy, Christophe Schwartz, Bojan Blazica, Chiara Piccini
SSS12.2

The implementation of the Soil Monitoring Law (SML) requires harmonized and operational monitoring systems capable of assessing soil condition, identifying degradation processes, and supporting sustainable soil management across Europe. Building on existing national and regional monitoring programmes, this session aims to showcase practical approaches, tools, and experiences that facilitate the transition from soil monitoring to evidence-based decision making.
We invite contributions addressing the development and application of soil health indicators, monitoring networks, assessment frameworks, and innovative technologies, including remote and proximal sensing, digital soil mapping, modelling approaches, and sensor-based monitoring. Particular attention will be given to methods for harmonizing and integrating datasets, establishing common assessment criteria, and supporting reporting and policy implementation across multiple governance levels.

The session will also highlight how monitoring information can support sustainable land management, soil restoration, climate and biodiversity policies, and stakeholder engagement, fostering the effective implementation of the Soil Monitoring Law and the protection of soil resources across Europe.

Convener: Stefano Mocali | Co-conveners: Antonio Bispo, Francesco VitaliECSECS, Maria Fantappiè
SSS12.3

Over the past decade, soil organic carbon has gained unprecedented prominence in international and European policy, from the launch of the “4 per 1000” Initiative to the EU Carbon Removals and Carbon Farming Certification Framework, Soil Monitoring and Resilience Directive and Mission “A Soil Deal for Europe”.
This session will address three complementary questions. First, what has actually changed? Contributions are invited to assess the effects of these initiatives on research agendas, stakeholder involvement, monitoring systems and land-management practices.
Second, what knowledge is now needed for credible public action? Contributions could examine how scientific knowledge on soil carbon can inform policy design, target-setting, implementation and evaluation, while considering trade-offs with other soil-health objectives.
Third, how can this knowledge become effectively usable? The session will welcome analyses of how evidence has been mobilized in the design and implementation of soil and climate policies, which institutional and collective arrangements have facilitated—or hindered—its use, and what lessons have been learnt.

Convener: Claire Chenu | Co-conveners: Elen Lemaitre Curri, Irene CriscuoliECSECS, Laure Bamière

SSS14 – Sessions related to ITS

ITS1.10/BG9.23 EDI

Monitoring carbon and greenhouse gas exchange between atmosphere, land, ocean and human systems underpins the Global Stocktake, national inventories, carbon markets and carbon dioxide removal (CDR). Yet bottom-up (inventories, process-based and data-driven models), top-down (atmospheric inversions) and bookkeeping (land-use change) estimates remain uncertain and often disagree, while the credibility of measurement, reporting and verification (MRV) rests on independent methods agreeing. Machine learning (ML) offers new ways to enhance, complement, emulate, integrate or even replace established observational, modelling and analytical workflows.

This session invites contributions using ML to advance carbon cycle monitoring and understanding across all compartments (atmosphere, vegetation, soils, permafrost, wetlands, inland waters, coastal and open ocean, anthropogenic sources) and all relevant trace gases, including CO2, CH4, N2O, CO, COS and isotopes. We welcome the full breadth of ML: foundation models, transformers, GNNs, CNNs, generative models (diffusion, flow matching), hybrid and differentiable modelling, Bayesian ML, symbolic regression, interpretable, robust and trustworthy ML, and tabular methods such as gradient-boosted trees. We particularly encourage work bridging science, policy and industry.
Topics include, but are not limited to:

- ML-enhanced bottom-up estimates: upscaling, mapping stocks and fluxes, inventories
- ML for top-down inversions: transport emulators, data assimilation, retrievals, point-source detection
- ML for bookkeeping and land-use change emissions
- Emulators and foundation models for process-based and Earth system models
- Hybrid modelling, and generative models for gap-filling, downscaling and ensemble generation
- Fusion of remote sensing with in-situ data (eddy covariance, flask networks, ocean pCO2)
- ML for carbon cycle process understanding and discovery: drivers, feedbacks and emergent constraints, with explainability, causality and uncertainty quantification
- Reconciling lines of evidence across methods, compartments and gases
- Monitoring for policy and industry: MRV, national inventories, carbon markets, CDR verification
- ML-based decision support and policy pathways (reinforcement learning, integrated assessment models)
- Benchmarks, datasets & open tools

Co-organized by AS3/ESSI1/SSS14
Convener: Vitus BensonECSECS | Co-conveners: Elena FillolaECSECS, Kai-Hendrik CohrsECSECS, Katarzyna (Kasia) Tokarska de los Santos, Carlos Rodriguez-PardoECSECS
ITS5.1/GM4.5

Landscapes are shaped by geomorphic processes, but life also shapes landscapes. Interactions and feedbacks between organisms, ecosystems and geomorphic processes structure many dynamic environments, including rivers, coasts, hillslopes, aeolian and deglaciating landscapes. Yet, many biogeomorphic feedbacks remain poorly understood and quantified, in particular their mechanisms, strength and thresholds. As these landscapes are increasingly affected by climate and land-use change, understanding how biota influence geomorphic processes—and vice versa—is becoming increasingly important. Improved understanding can support nature-based solutions (NbS) and geoheritage conservation and contribute to the conservation of geodiversity and biodiversity, as well as the maintenance of ecosystem functions and services.

Our session brings together research on interactions between plants, animals, ecosystem processes and geomorphic processes, landforms and materials. We particularly seek to connect researchers working in environment-specific communities, including fluvial, coastal, aeolian and hillslope geomorphology, and provide a forum to explore common biogeomorphic processes and feedbacks across environments. We welcome research spanning functional traits and individual organisms to ecosystems and landscapes, from mountain environments to the sea. By bringing together studies from different environmental settings, we aim to identify common principles, context-dependent contrasts and transferable insights in biogeomorphology, and foster synergies between research communities.

Topics may include, but are not limited to:
• biogeomorphic processes, rates and feedbacks;
• the role of plant and other organisms’ traits in geomorphic processes;
• biota as ecosystem engineers, landform creators and landscape shapers;
• biogeomorphic feedbacks under climate and land-use change;
• applications of biogeomorphology for nature-based solutions, hazard mitigation and geoheritage conservation

Innovative approaches—including field monitoring, laboratory and flume experiments, remote sensing, artificial intelligence, numerical and statistical modelling, and combinations thereof—are warmly welcomed, especially when providing new insights into interactions between life and landscape, resolving previously inaccessible interactions or pushing scalar boundaries.

Co-organized by BG10/CR4/SSS14
Convener: Jana Eichel | Co-conveners: Stefan HaselbergerECSECS, Borbála Hortobágyi, Robert HouseagoECSECS, Zhicheng YangECSECS