Modelling is fundamental for assessing various soil processes and interactions at different scales and resolution, while healthy soils are fundamentally important in sustaining a wide range of ecosystem services. Crossing interdisciplinary borders and integrating knowledge from various fields is essential in developing more accurate and comprehensive models to better capture the complexity of soil processes/mechanisms in natural and cultivated systems, address knowledge-gaps, and tackle the challenges related to data-integration, heterogeneity and uncertainty of modelling predictions across disciplines. An interdisciplinary approach is also needed in light of recent technological advances, such as computational approaches, model-coupling, geomatics, remote sensing/earth observation, machine learning, surveying and data collection sensors/sensor platforms, real-time data-streams, all of which provide opportunities for promoting new modelling generations integrating soil science across disciplines.

Integration of various disciplines and modelling is also essential for better understanding of the role of soil health, which includes concepts soil capacity and functionality towards a wide range of ecosystem services. Several measures to support soil health and tackle soil degradation have been proposed in the scientific literature, as well as several indicators to monitor expected benefits. The need for standardized data covering the broad concept of soil health and degradation is arising, along with the lack of information on relationships between soil quality and agriculture, forest and grassland resilience, and the socio-economic and environmental impacts of these measures. The scattered data availability and their complex integration for agronomic/environmental management and policy decisions may partly be covered by many European/international/national initiatives in the frameworks of the H2020, Horizon Europe, PRIMA, FAO programs, and other programs.

This session aims to promote and enhance communication and exchange of knowledge among scientists from modelling community, soil research and various related projects, linking different disciplines, and is open to contributions in a wide range of related topics, ranging from modelling soil systems to ecosystem and landscape modelling, soil health, degradation and living labs, while striving to contribute towards tackling current research challenges, addressing the knowledge-gaps, and informing policy.

Nature-based Solutions (NbS) are actions to protect, conserve, restore, sustainably use and manage natural or modified ecosystems, that address socio-economic and environmental challenges, while simultaneously providing human well-being, resilience and biodiversity benefits (UNEA, 2022). Within the framework of a global ecosystem approach, NbS must encompass ecological, societal, political, economic and cultural issues at all levels, from the individual to the collective, from local to national, from the public or private sphere.

As recently highlighted by IPCC and IPBES, climate change and biodiversity degradation cannot be separated, and must be considered together. For this reason, this session is especially focused on the way NbS can act as climate change adaptation solutions. Considering various ecosystems (marine and coastal, urban, cropland, mountainous, forest, rivers and lakes,.,), NbS as interventions for climate adaptation includes the adaptation to: sea level rise (flooding and erosion), changes of the water regime (floods, droughts, water quality and availability), rise in temperatures (heat waves, forest fires, drought, energy consumption), plant stress and increase of pests (variation of yields, forest dieback), to minimize their associated social and economic negative impacts.

Therefore, this session aims to promote interdisciplinary research related to ecosystem restoration, preservation and management, to put forward the complexity that is often hidden by simplifying hypotheses and approaches (sector-based silo approach, homogeneity of environments, ...).

Specific topics of interest are the followings:
- Complexity: nature of ecosystems and the risk of oversimplification, interconnection between NbS and complementary areas, consideration of uncertainties (future climate and associated impacts...)
- Scales: spatial scales with the integration of NbS in their environment, and temporal scales considering sustainability over time, variability of bio-physical processes and climate change effects
- Ecosystem services: understanding the bio-geophysical processes, spatial shift between the location of NbS and the location of beneficiaries, modification under climate change (threshold, inflection point), co-benefits or on the contrary degradation and negative effects
- Assessment and indicators: measurement and modelling protocols to evaluate NbS performances, capacity to measure the complexity, resilience and stability of the solutions.

Geoscience knowledge and practices are essential for effectively navigating the complexities of the modern world. They play a critical role in addressing urgent global challenges on a planetary scale (including, climate change and its social, humanitarian, and health impacts), informing decision-making processes and guiding education at all levels. However, the response to these challenges remains largely inadequate across the board.
By equipping both citizens and the wider societal stakeholders with the necessary knowledge background, geosciences empower them to engage in meaningful discussions, shape policies, contribute to reduce inequities and injustice, and implement solutions for local, regional, and global social-environmental problems. Within this broad scope, geoethics strives to establish a shared ethical framework that guides geoscientists’ engagement with sensitive and significant issues concerning the interaction between geoscience and society.
This session will cover a variety of topics, including theoretical and practical aspects of geoethics, ethical issues in professional practice, climate and ocean education, geoscience communication, and strategies for bridging the gap between geosciences and society.
This session is co-sponsored by the International Association for Promoting Geoethics, the Commission on Geoethics of the International Union of Geological Sciences and the Chair on Geoethics of the International Council for Philosophy and Human Sciences (www.geoethics.org).

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

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

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

This session is co-organised with the EGU early career scientists (ECS) and the European Research Council (ERC).

Soil erosion is a major global soil degradation threat to land, freshwater and oceans. Scientific understanding of all erosional physical processes controlling soil detachment, transportation, and deposition is vital when developing methods and conservation alternatives to minimize the impacts associated with soil degradation and support decision making.

This session will discuss the latest developments in soil erosion and closely associated land degradation processes in agriculture, forest and rangelands. Providing space for presenting and discussing:

• measurements - from rill to gully erosion, by means of field essays or laboratory experiments;
• monitoring - short to long-term assessments, by mean of local assessments or remote sensing techniques;
• modelling approaches – from plot to global scale, addressing current and future land and climate change demands;
• mitigation and restoration – to address on-site and off-site impacts on soils and water.

Our main objective is to scientifically discuss soil erosion processes and impacts but also to explore strategies that may help land stakeholders (farmers, land managers or policy makers), and support the ongoing initiatives aiming for land degradation neutrality by 2030 and the upcoming UN Decade on Ecosystem Restoration (2021-2030).

Water erosion is one of the most widespread forms of soil degradation and agricultural productivity loss as well as a substantial driver in morphogenesis and landscape evolution.
In the context of global change, the erosion process is expected to intensify due to an alarming potential for climate change, mainly due to an increase in the frequency of extreme precipitation and localised events. Furthermore, the anthropic action involving changes in land use and increasing erosive crops can contribute to the aggravation of the phenomenon.
In this session is expected to collect contributions for discussing over subjects dealing on:
1. Soil erosion modelling, especially as part of scenario analysis in various contexts. Such an approach has grown exponentially in the last decades becoming a current tool for exploring new horizons in erosion prediction. It may include new data processing methodologies with local and global approaches to improve understanding of long-term behaviors and determine possible trajectories due to the impact of erosion factors such as climate and land-use change.
2. Erosion modelling and assessment based on alternative data such as remote and proximal sensing, fingerprinting of sediment sources, benchmarking, etc. over a wide range of scales and methods. This is in response to the increased availability of observational data, especially from satellite, allowing detailed monitoring of the processes.
Publication of the contributions in a Special Issue publication is foreseen.

Traditional categorizations of soil erosion encompass sheet, rill, and gully erosion as distinct forms. Rill and gully erosion are particularly noteworthy as they concentrate surface runoff, intensifying erosive forces. These modes of concentrated erosion serve as significant contributors to sediment in watersheds and result in substantial economic setbacks, such as diminished crop yields and reservoir sedimentation. Furthermore, rills and gullies serve as crucial conduits for transporting runoff, sediments, and contaminants. Despite their importance, the underlying physical mechanisms driving concentrated erosion remain shrouded in uncertainty.
This session aims to bridge this research gap and will place its emphasis on recent investigations seeking to enhance our comprehension of the rill and gully erosion processes, all with the ultimate goal of developing predictive tools and effective management strategies. Consequently, we eagerly invite contributions related to various aspects, including monitoring and measurement techniques, the factors and mechanisms governing rill and gully erosion, modeling approaches, restoration and control methods, and the role played by rills, and gullies in the broader context of hydrological and sediment connectivity.

Torrent control works and soil conservation techniques play pivotal roles in managing catchment hydrology and morphology, regulating water resources, and supporting agricultural activities. Despite their global significance, certain scientific aspects remain unexplored, such as suitable planning and design of restoration actions, prediction of degradation over time, quantification of effectiveness, and assessment after extreme hydrological events. The scarcity of long-term monitoring studies further complicates these pursuits. Remote sensing (RS) emerges as a valuable tool for analyzing past and current situations and monitoring catchment morphology evolution through multi-temporal surveys.

This session aims to foster collaboration and discussion among soil scientists, hydrologists, geomorphologists, and stakeholders. We encourage research contributions on innovative planning and design protocols, emerging techniques for multi-temporal or real-time monitoring using RS, standards for comprehensive analysis of structural and functional conditions, and identification of new challenges like soil-bioengineering techniques and integration of vegetation in check dam systems.

Additionally, the session addresses the quantification of sediment sources and dynamics in river catchments within the context of land use and climate change. Obtaining quantitative information on soil redistribution patterns during storms and identifying sediment sources are essential for designing effective control measures. Sediment tracing and fingerprinting techniques, coupled with soil erosion modeling and sediment budgeting, have contributed significantly, but challenges persist. Contributions are invited on innovative field measurement and sediment sampling techniques, tracing studies using various approaches, investigations of current limitations, applications of radioisotope tracers, and integrated approaches linking different measurement techniques and models for understanding sediment delivery processes.

This integrated approach seeks to address the complex interplay between torrent control, soil conservation, and sediment dynamics, offering a comprehensive perspective on sustainable catchment management. Early career scientists are encouraged to contribute with original and advanced studies.

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.

It is clear that human impact on earth surface processes is almost ubiquitous. At present the scale of human impacts upon geomorphic systems is considerably larger than at any point in the past with a plenitude of either direct or indirect impacts on the systems’ structure and function. This session aims to provide a platform for studies on the role of humans as agents of geomorphic change and associated environmental feedbacks. We also welcome studies which conceptionally discuss the importance of geomorphology as a discipline within the overall Anthropocene debate. We look for both, conceptional contributions, and quantitative approaches, e.g. based on modelling and/or field surveys, addressing the effects of human agency on all geomorphological process domains (aeolian, fluvial, cryospheric, coastal, hillslope). This could include, but is not limited to the effects of construction works, river engineering, land use/management, or climate change. Moreover, this session especially welcomes studies contrasting natural and human dominated systems.

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.

Microbial metabolism is the engine of key soil functions (e.g. nutrient cycling, carbon transformation, clean water provision) with this engine’s performance determined by energy and matter fluxes that follow the laws of thermodynamics. For growth and anabolism, microbes require not only C and energy, delivered chiefly by the oxidation of soil organic matter (SOM), but various nutrients (e.g., N and P) in stoichiometric relationships. Soil microorganisms therefore couple energy and element flows via complex mechanisms whereby organic matter may be mineralized, invested in cellular reproduction or transformed into a diversity of storage compounds and microbial products. Microbial death processes close the loop to return biomass to non-living SOM as necromass, changing its original quality. This coupled, dynamic system can be investigated from diverse perspectives, such as carbon or energy use efficiency, microbial ecophysiology, bioenergetics, and ecological stoichiometry. Knowledge of the drivers and regulators of microbial energy and matter fluxes is needed to understand the balance between SOM mineralization and accumulation as well as associated C, energy and nutrient budgets. This session integrates experimental, conceptual and modelling insights to elucidate the energy and matter flows governed by soil microbial metabolism and bioenergetics, their dependency on environmental conditions, and the implications for soil functioning.

The session seeks to understand how, when and where soil microorganisms transform OM and energy through their metabolism, growth and death and how bioenergetics regulates these processes. Topics of interest include characterization of microbial turnover and SOM using advanced methods (e.g., isotopic labelling, calorimetry), alongside approaches revealing the effect of microbial community composition and activity on soil functions, and functional responses to environmental change. The session will stimulate innovative and interdisciplinary discussions to advance the field of soil biology at scales from the mechanistic understanding of biogeochemical processes to global change.

Soil health is the capacity of soil to function within ecosystem and land-use boundaries to sustain biological productivity, maintain environmental quality, and increase plant, animal, and human health. In the current context of global change, characterized by the convergence of extreme events and human activities such as intensive fertilization, pesticide application, mismanagement of landfills, nuclear accidents, etc., it is crucial to prioritize soil health. This explains the widespread adoption of sustainable agricultural practices aimed at preserving and/or improving the physical and chemical fertility of the soil. Furthermore, limiting the negative impacts of these practices on soil microbial communities prevents the alteration of the biogeochemical cycles of carbon and nutrients.
We invite field, laboratory and modeling studies on soil health analyzing the effects of human activities on soil organic matter content and composition, microbial functions and enzymatic activities, regulation of nutrient cycles, detoxication of organic pollutants and other relevant indicators. This session considers contributions that examine how soil health influences the delivery of ecosystem services such as provisioning, regulatory, supporting, and cultural services. Contributions covering studies on soil health from a micro to a global scale are highly appreciated.

Microbial hotspots in soils such as the rhizosphere, detritusphere, biopores, hyphasphere, aggregate surfaces, pore space and biocrusts, are characterized by high activity and fast process rates resulting in accelerated turnover of soil organic matter and other microbial functions (e.g. nutrient mobilization, litter decomposition, respiration, organic matter stabilization, greenhouse gas emission, acidification, soil stabilization, or hydrological processes (e.g. by biocrusts). The intensity of microbial and SOM turnover as well as nutrient cycling in such hotspots is at least one order of magnitude higher than in the bulk soil.
This session invites contribution to: 1) Various aspects of microbial activity, interactions, communities composition, growth and distribution in hotspots; 2) Factors influencing (micro)biological nutrient (re)cycling including biotic and abiotic controls (e.g. climatic extreme, warming, drought, contamination, land use and human activities, etc) are strongly encouraged; 3) The session will also present and discuss new developments to assess the crucial microbial mechanisms that underpin biogeochemical processes in hotspots (e.g. approaches assessing the variability in soil activity within the soil matrix, notably focusing on microbial molecular analysis, imaging methods, revealing spatial-temporal gradients of functional biodiversity, enzyme activity and substrates turnover, input and uptake by roots, soil structure modification by root growth; 4) Studies of feedback loops between these processes and biotic/abiotic factors altering nutrient cycling, water availability, soil structure and resilience to climate change are very much appreciated; 5) Combination of experimental and theoretical approaches and modelings to predict the fate and functions of microorganisms in hotspots are highly appreciated.

The physical environment of soils is continuously changing. Soil biota, root growth, land management practices like tillage and abiotic drivers lead to a constant evolution of the arrangement of pores, minerals and organic matter and herewith to modifications in the soil physical functions and chemical properties. Especially in regions with high biological activity, soil organisms induce remarkable alterations to soil structure and functions to optimize growth and reproductive conditions. Resolving the underlying mechanisms forcing such adaptive modifications and exploring the feedbacks between the drivers including the impact of management practices 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 on how the rhizosphere and its microbiome control fluxes beyond the pore scale; on how management practices affect soil structure and functions; on the role of biological soil curst in modifying 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.

Soil microbial communities exert control over carbon and nutrient cycling and they are playing a central role in shaping the impacts of anthropogenic greenhouse gas emissions on the global climate. These communities are also susceptible to both gradual shifts in climate and abrupt weather events, which can trigger substantial feedback loops in biogeochemical cycling. Therefore, understanding the impacts of climate and environmental stressors on soil microbial communities and their functioning is essential for forecasting the future trajectory of ecosystem-level biogeochemical cycling of carbon and nutrients.

This session aims to shed light on the effects of diverse climate scenarios on soil microbial communities, biogeochemical cycling, and their feedback to climate change. Our focus spans over diverse aspects of climate change, ranging from gradual shifts such as increasing temperature or atmospheric CO2 levels, to the influence of extreme weather events like drying-rewetting cycles, heatwaves, or floods. We invite studies that investigate the resilience and associated recovery dynamics of soil biota to environmental disturbances, as well as investigations on their resistance or adaptation mechanisms. We also welcome research on the interactions between soil microorganisms, plants and fauna. With this session, we aim to foster connections among researchers from diverse disciplines, establishing a discussion platform to review the current state of the-art, identify knowledge gaps, exchange ideas, and address emerging challenges within the field.

Climate change is one of the most critical challenges facing humanity. Microorganisms play a pivotal role in both production and consumption of the major greenhouse gases (GHG): carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). To mitigate the emissions of these GHGs and the escalating impact of global warming, a better understanding of the microbes, their processes and environmental drivers and their effect on the GHG balance is needed. Depending on the environmental conditions, terrestrial microbes can change landscapes to significant sources or sinks of GHG.
This session aims to bring together scientists in microbiology, biogeochemistry, and soil and GHG sciences to advance our understanding of the carbon and nitrogen cycling in the soil-plant-atmosphere continuum affecting GHG emissions.
One important focus of this session is on microbial processes such as decomposition, respiration, methanogenesis, methanotrophy, nitrification, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) are directly responsible for the microbial GHG fluxes, and their rates differ in organic and mineral soils and in temperate and tropical ecosystems. These processes and the microbes can be studied in lab and field experiments using different methods, for example, quantifying functional marker genes, omics-based approaches (including sequencing and metagenomics), culturing, isotopic analyses, and GHG measurements and modelling.
Another important focus is on the environmental drivers and key factors, including physical soil structure (porosity, texture, structure), soil chemical properties (pH, Redox) and soil conditions (temperature, water content). Understanding the interplay between these factors and the main transport mechanisms in the liquid and gas phases is also essential to understand microbial interactions and their effect on GHG turnover in soils, as well as non-microbial geogenic or technical GHG fluxes.
In this session, we encourage submissions containing small to large spatial and temporal scales, new methodologies, mechanistic studies in model organisms, and studies in different terrestrial ecosystems locally and globally, aiming to tackle the aforementioned challenges by studying the processes and microbial communities underpinning net GHG fluxes and other emissions such as volatile organic compounds (VOC).

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 as long as 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. Alongside this, advances in methods for monitoring and modelling rates of soil carbon loss or carbon sequestration in soils are key to inform political, agronomical, and geo-engineering approaches. Is there a threshold above which a soil profile can no longer increase its carbon stock? What determines the fate of C inputs to the soil? What are the mechanisms determining differences between soils’ capacity to stabilise C?

Regulation of the cycles of carbon (C) and nutrients (N, P, S) in soils and ensuring their linkage and retention are recognized as major challenges, especially under shifts in environmental factors (warming, drought, N deposition, overfertilization, salinization, alterations of landscapes, biodiversity loss, invasion of species and intensification of land use). The processes underlying C and nutrient cycling in soils are difficult to evaluate and separate since multiple factors can shift process rates and directions, as well as determine pool sizes. Factors also frequently have an interactive effect. Estimating the magnitude of C and nutrient pool response and the temporal scale of reactions to land use change or shifts of environmental factors remains a major challenge. Thus, this session invites contributions focused on evaluating the soil C, N, P, and S pools and process responses under global change scenarios at the local and larger scales. Studies that combine short-term laboratory observation focused on process rate estimation with long-term field experiments and evaluation of pools are highly welcome. Studies that focus on the effect of soil chemistry, including an application of isotopes to investigate the process rates, mineralogy, as well as the transition from conventional to organic agriculture/land restoration, are also highly relevant.

Understanding the partitioning of carbon in different reservoirs on Earth, and the sensitivity of these reservoirs to climatic and anthropogenic factors, remains a key challenge in predicting future responses to global warming. A lot of this uncertainty stems from the inherent complexity of the carbon cycle, where physical, chemical, and biological processes interact on different temporal and spatial scales. Thus, a wide variety of tracers are needed to unravel individual processes and assess their sensitivity to climatic and anthropogenic influences.

Natural Organic matter (OM) is globally ubiquitous and a keystone interactive medium in environmental ecosystem functioning. The vast molecular diversity of natural OM may be both a symptom or a cause of its mediating role in various processes essential for life on Earth, such as nutrient retention and resupply, or climate stability. Dissolved organic matter (DOM) forms the main carbon and energy source for microbial life, still it accumulates in the oceans to one of the biggest carbon reservoirs on Earth. Pyrogenic organic matter (PyOM) is an important component of OM and is characterized by its condensed aromatic composition. It originates from natural (e.g., wildfires) and anthropogenic sources (e.g., biochar) and despite the importance of PyOM in the environment, its processing and fate remain largely unknown.

In this session, we aim to bring together the latest insights into the partitioning and size of all reservoirs of the global carbon cycle and the processes governing fluxes of carbon between these reservoirs. We invite contributions from process- to field-scale approaches and method development for a detailed understanding of isotopic and molecular composition of individual carbon reservoirs, as well as their active role within ecosystem functioning. We are interested in studies showing new field data, laboratory experiments and modeling that use geochemical tracers (e.g., 14C, biomarkers, stable and non-traditional isotopes, trace elements) combined with geomorphic and hydrological tools to unravel controls on the carbon cycle from the local to the global scale. Modern analytical tools and their combination are crucial in advancing this research field, encompassing a variety of spectroscopic and mass spectrometric techniques (AMS, NIR, MIR, NMR, XPS, py-GC-MS, HR-MS, LC-MS-MS, EEMs-PARAFAC, PTR-MS, etc.) as well as new computational approaches.

Soil systems harbor a highly diverse spatial organization of its functions shaping biogeochemical cycles. From microbial microenvironments via physical soil structure and various chemical differentiation by pedogenetic or anthropogenic processes up to the landscape scale. In this session, we invite diverse studies that open our views on the spatial heterogeneity in soils from biological, physical, and chemical perspectives related to organic matter dynamics and other biogeochemical cycles.

We look forward to discuss insights across different scales and structures. Zooming in provides the opportunity to observe microbial habitats and processes, probe highly active spheres around roots or detritus, and follow the interactions of organic matter with mineral phases. Aggregated structures and a network of soil pores provides a dynamic scaffolding, which can protect soil components and influence local water retention and elemental distribution. Pedogenetic soil processes drive the differentiation at pedon scale and can result from a combination of small-scale processes determining soil ecosystem fluxes up to the landscape scale.

This session is of interest to soil scientists with complementary biogeochemical and physical backgrounds working at different scales. We especially encourage contributions that address the importance of spatial heterogeneity and architecture for ecosystem-relevant soil functions, such as the occlusion of organic residues, microbial colonization, provision of water and nutrients, the fate of soil contaminants, and many more. Different experimental imaging approaches, analytical techniques and data-driven modelling works are invited. We aim to discuss recent achievements, current obstacles, and future research directions to strengthen our conceptual understanding of the linkage of spatial heterogeneity with soil functions, biogeochemical cycling, and organic matter dynamics across scales.

Soil is the largest carbon (C) reservoir in terrestrial ecosystems and soil organic carbon (SOC) is the basis for soil’s biodiversity, health and fertility. The sustainable management of ecosystems to enhance both, soil and subsoil organic C storage is one strategy to mitigate climate change and to provide soil-related ecosystem services. However, long-term C sequestration is critically dependent on short-term and long management, including the input of other nutrients, soil intrinsic characteristics and land use.
Investing in productive, highly resilient and sustainable ecosystems, based on appropriate land and soil management requires the knowledge base on drivers and processes controlling soil C storage and cycling.
Thus, this session will provide knowledge about the key mechanisms and proxies controlling physico-chemical and microbial dynamics of soil Carbon-Nitrogen-Phosphorus (CNP) (both organic and inorganic) to foster higher soil C sequestration and enhance the sustainability of agricultural and (semi-)natural systems.
Studies, opinions and other contributions in this session will aim to a wide range of topics related to SOC and soil inorganic carbon (SIC) and the relationship between them. These topics may also include soil fertility, provision of ecosystem services, and their changes. Ultimately, approaches informing management strategies in agricultural and natural systems will be summarised to help the translation of scientific knowledge into policy frameworks.
Types of contribution appreciated include, but are not limited to, definitive and intermediate results; project outcomes; proposal of methods or sampling and modelling strategies, and the assessment of their effectiveness; projection of previous results at the light of climate change and climatic extremes; literature surveys, reviews, meta-analysis; and opinions. These works will be evaluated at the light of the organization of a special issue in an impacted journal.

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

Direct anthropogenic perturbations of the P cycle, coupled with other human-induced stresses, have impacted numerous environments. Forest ecosystems may be losing their ability to recycle P efficiently, due to excessive N input, extensive biomass removal, and climatic stress. Soils, which serve as the biogeochemical fulcrum of the terrestrial P cycle, have been greatly altered by fertilizer use in recent decades. Changes in the P cycle on land impact on the magnitude and timing of P fluxes into aquatic ecosystems, influencing their trophic state. Burial in sediments returns P to the geological sink, eventually forming economically viable P deposits. Throughout the P cycle, redox conditions play a key role in transformations and mobility of P.

This interdisciplinary session, now celebrating its 10th anniversary at EGU, invites contributions to the study of P from across the geosciences, and aims to continue fostering links between researchers working on different aspects of the P cycle. We target a balanced session giving equal weight across the continuum of environments in the P cycle, from forests, soils and groundwater, through lakes, rivers and estuaries, to oceans, marine sediments and geological P deposits. We welcome studies of both past and present P cycling, with a focus on novel techniques and approaches.

This is the new edition of 2023's successful session on the same topic and focus. We would like to continue bringing people together with this session in order to learn from each other’s studies on soils and climate change from a global range of pedogenic and environmental settings.
Climate change is affecting the dynamic feedbacks between plant, soil, and microbial communities and thus strongly influences terrestrial biogeochemical cycling. In this session we address the question: What is the impact of changing environmental conditions on the plant-soil system, and what are the resulting effects on soil biogeochemistry? Given the positive and negative feedbacks with the climate system, dynamics of soil organic matter across terrestrial ecosystems are a key focus of this session.
We invite contributions from manipulative field experiments, observations in natural-climate gradients, and modelling studies that explore the climate change impacts on plant-soil interactions, biogeochemical cycling of C, N, P, microbial diversity and decomposition processes, and deep-soil biogeochemistry. Submissions that adopt novel approaches, e.g. molecular, isotopic, or synthesize outputs from large-scale, field experiments focusing on plant-soil-microbe feedbacks to warming, wetting, drying and thawing are very welcome.

This year's invited speakers are: Dr. Kaizad Patel (Pacific Northwest National Lab) and Dr. Melanie Brunn (Koblenz University)

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