Fire is the primary terrestrial ecosystem disturbance globally and a critical Earth system process. Its frequency and intensity are expected to increase across most regions in the future, posing significant challenges for ecosystems, the carbon cycle, and society. Fire research is rapidly expanding across disciplines, underscoring the need to advance our understanding of fire's interactions with climate, the biosphere, and human systems. This session invites contributions investigating the role of fire in the Earth system at any spatiotemporal scale, using statistical (including AI) or process-based models, remote sensing, field and laboratory observations, proxy records, and data-model fusion techniques. We strongly encourage abstracts on fire's interactions with: (1) weather, climate, atmospheric composition, chemistry, and circulation, (2) vegetation composition and structure and biogeochemical cycle, ocean ecosystems; (3) cryosphere elements and processes (such as permafrost, sea ice), and (4) human health, land management, conservation, and livelihoods. Moreover, we welcome submissions that address: (5) spatiotemporal changes in fire (especially extreme fires) in the past, present, and future, 6) fire products and models, and their validation, error/bias assessment and correction, as well as (7) analytical tools designed to enhance situational awareness for fire practitioners and to improve fire early warning systems.

This session focuses on volatile organic compounds (VOCs) at the biosphere-atmosphere interface, encompassing innovative analytical methods, laboratory and field studies, and emission modelling approaches.

We invite contributions on plant and other biogenic VOC emissions sources (e.g., from soil, litter, and freshwater) under environmental changes and welcome contributions on methodological advances in sampling and analysis techniques, and modelling frameworks that bridge experimental observations with atmospheric processes.

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

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

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

Understanding and predicting ecosystem responses to global change is increasingly urgent, as terrestrial ecosystems are exposed to more frequent and intense climatic extremes such as droughts, heatwaves, floods, wildfires, and/or permafrost thaw. These stressors profoundly affect vegetation dynamics and impact soil functioning through the disruption of tightly coupled carbon, water, and nutrient cycles, with consequences for ecosystem resilience, recovery trajectories, and feedbacks to the climate system.

This session focuses on ecosystem responses to global change and extreme events, emphasizing the tight coupling between biogeochemical and water cycles and their effect on vegetation. Plant physiological responses to stress, such as changes in photosynthesis, transpiration, carbon allocation, and nutrient uptake, directly alter ecosystem-scale carbon, water, and nutrient fluxes and interact with soil processes by shaping soil moisture regimes, microbial activity, and the decomposition and stabilization of organic matter. Conversely, biogeochemical changes triggered by extremes include altered nutrient availability, mineral transformations, soil chemistry changes, and can have strong feedbacks on vegetation functions, recovery, and competitive interactions. Studying these interconnected processes is essential to improve mechanistic understanding of ecosystem resistance, resilience, and legacy effects following stress and disturbance in order to develop sustainable management interventions.

We welcome contributions across multiple spatial and temporal scales using laboratory experiments, field observations, remote sensing, modelling, novel analytical techniques, data synthesis, and/or presenting innovative management strategies. The session aims to foster interdisciplinary discussion at the interface of vegetation functioning, soil processes, and biogeochemical cycling, to advance understanding of ecosystem responses in a rapidly changing world.

Plant hydraulics regulate water transport, photosynthesis and transpiration, thus controlling vegetation productivity, carbon uptake, and vulnerability to e.g. drought and heat. Key hydraulic traits such as conductivity and capacitance are fundamental to ecosystem resilience but remain challenging to monitor and model across scales. Vegetation water content (VWC) provides a critical integrative measure of hydraulic status and dynamics, offering actionable indicators for ecosystem monitoring, agricultural and forestry management, and early warning of stress. Nevertheless, hydraulic variables and VWC remain difficult to observe consistently: signals vary from leaf to landscape, are confounded by soil moisture, vegetation structure, and temperature, and exhibit strong diurnal/seasonal dynamics that challenge cross-sensor harmonisation and validation.

This session welcomes both methodological advances, applications and validations. We emphasise developments in passive and active microwave (radiometry, radar) retrievals, GNSS-based approaches (transmissometry, reflectometry), and optical/thermal methods, alongside in situ measurements (e.g., leaf/stem water potential, dielectric probes, dendrometry) and model-data integration.

We invite contributions that: (i) improve retrieval algorithms, including cross-frequency synergies; (ii) fuse microwave/optical/LiDAR with in situ data to bridge scales; (iii) quantify uncertainties and disentangle confounding factors; (iv) integrate observations into ecohydrological and land-surface models via data assimilation and machine learning, and advance model representation of plant hydraulics, improve the coupling between the water and carbon cycles, and make use of emerging observations; and (v) use hydraulic observations and products, including VWC and related metrics, to resilience and disturbance/recovery assessment, drought monitoring and early warning, phenology, and agricultural/forestry management.

Case studies, global syntheses, and contributions providing open datasets, intercomparisons and community benchmarks are encouraged. The session aims to foster discussion between attendees from various scientific communities approaching plant hydraulics from different perspectives.

Surface exchange fluxes of heat, momentum and mass above the global oceans and at the poles (snowpack, sea-ice, ocean and land) have significant impacts on atmospheric composition, biogeochemistry and climate at regional to global scales. Atmospheric boundary layer processes mediate these chemical and physical fluxes. This session is intended to provide an interdisciplinary forum to bring together researchers working in the areas of meteorology, atmospheric chemistry, air quality, biogeochemistry, stable isotope research, oceanography, and climate above the global oceans and in the polar regions.

The session focuses on new research in several areas which include: air-sea fluxes of climate-active trace gases (CO2, CH4, N2O) mediated by the atmospheric boundary layer above the oceans and in polar regions; regional emission and vertical mixing of aerosol, such as cloud-forming particles (CCN/INP) and their precursors (including dimethyl sulfide (DMS), marine organic compounds and halogenated species) and their impacts on atmospheric composition and climate; atmospheric deposition of nutrients (e.g., nitrogen, phosphorus, iron) and its impact on ocean biological systems; and biogeochemistry-climate feedback loops in the ocean-atmosphere system. We also welcome studies on how these surface fluxes may change in response to climate warming, as well as the local to large-scale influences on these exchanges. An adequate understanding and quantification of these processes is necessary to improve modeling and prediction of future changes above the oceans and in the polar regions, their teleconnections with mid-latitude weather and climate (including meridional transport of heat, moisture, chemical trace species, aerosols and isotopic tracers), and the coupling between local and large-scale dynamics.

The session has strong links to the Surface Ocean ̶ Lower Atmosphere Study (SOLAS) and the GESAMP Working Group 38 on atmospheric input of chemicals to the ocean. Submissions are encouraged from all areas covered by these programs, using a range of analysis approaches including field measurements, remote sensing, laboratory studies, and atmospheric and oceanic numerical models.

This year we particularly welcome studies on the impact of extreme events on air-sea gas exchange of climate-relevant compounds in marine systems. Here we invite contributions addressing physical drivers such as marine heatwaves, storms and tropical cyclones, circulation anomalies or sea ice changes; biogeochemical drivers such as hypoxic or anoxic conditions and acidification pulses; biological drivers such as harmful algal blooms; or compound events. Relevant studies may address impacts in all oceanic domains; e.g., open ocean, shelf waters and shallow (< 20 m depth) coastal ecosystems. The reporting on progress as well as critical knowledge gaps in polar regions will help define upcoming research programmes as part of Antarctica InSync and the International Polar Year 2032-33.

Land–atmosphere interactions often play a decisive role in shaping climate extremes. As climate change continues to exacerbate the occurrence of extreme events, a key challenge is to unravel how land states regulate the occurrence of droughts, heatwaves, intense precipitation and other extreme events. This session focuses on how natural and managed land surface conditions (e.g., soil moisture, soil temperature, vegetation state, surface albedo, snow or frozen soil) interact with other components of the climate system – via water, heat and carbon exchanges – and how these interactions affect the state and evolution of the atmospheric boundary layer. Moreover, emphasis is placed on the role of these interactions in alleviating or aggravating the occurrence and impacts of extreme events. We welcome studies using field measurements, remote sensing observations, theory and modelling to analyse this interplay under past, present and/or future climates and at scales ranging from local to global but with emphasis on larger scales.

Droughts, characterized by precipitation deficits and high evaporative demand, are becoming increasingly frequent, prolonged, and intense under global environmental change. Climatic drivers (such as altered precipitation regimes and rising temperatures) and land surface modifications (including vegetation greening, deforestation, land-use transitions, and wildfires) interact in complex ways to shape ecohydrological responses to droughts across spatial and temporal scales.
This session invites contributions that explore how ecosystems and hydrological processes respond to droughts (hereafter referred to as drought responses), aiming to uncover both underlying mechanisms and broader consequences. We welcome studies based on observational, modeling, and conceptual approaches. Topics of interest include, but are not limited to:
1. New insights into drought responses based on emerging in-situ and satellite observations of soil moisture, evapotranspiration, and vegetation dynamics.
2. Process-based understanding of ecohydrological responses to droughts of varying severity under changing climate and land surface conditions.
3. Long-term trends and resilience of ecohydrological systems under recurrent droughts, with a focus on resistance, recovery, and key environmental drivers.
4. Advances in modeling frameworks (process-based or AI-based) and observation-constrained approaches for improving the representation of drought responses.
5. Social and ecological impacts of evolving droughts, including implications for ecosystems, agriculture, water resources, and human well-being.
By integrating hydrology, ecology, and remote sensing, this session seeks to advance our understanding of ecohydrological drought responses and to inform sustainable adaptation strategies in a changing environment.

Stable and radiogenic isotopic records have been successfully used for investigating various terrestrial and marine sequences in term of special events including geological boundaries, fossils, evaporative rocks, palaeosols, lacustrine, loess, caves, peatlands. The session includes contributions using isotopes along with sedimentological, biological, paleontological, mineralogical, chemical records in order to unravel past and present climate and environmental changes or as tracers for determining the source of phases involved. Directions using triple isotopes, clumped isotopes, biomarkers and non-traditional stable isotopes are welcomed.
Contributions presenting an applied as well as a theoretical approach are invited, including papers related to reconstructions (at various time and space scales), fractionation factors, measurement methods, proxy calibration, and verification.

Environmental changes and the geodynamic evolution of continents have facilitated both the emergence of life on Earth and the diversification of mineral species from the early Archean until today. However, the physico-chemical conditions of ancient environments remain poorly understood, particularly regarding the processes and consequences of major oxygenation events (e.g., the Great Oxidation Event, Neoproterozoic Oxygenation Event, and Phanerozoic Oceanic Anoxic Events) and associated mass extinctions, as well as the influence of continents and mantle processes in modulating ocean chemistry at different times in Earth’s history.
Understanding key processes shaping modern and ancient environments; such as weathering, hydrothermal alteration of the oceanic crust, bacterial activity, sedimentation, and diagenesis; is crucial for reconstructing paleo-environments. Redox processes and Earth’s oxygenation during critical transitions and biotic crises are central to unraveling the links between environmental change and biological evolution.
With this session, we encourage contributions from the interdisciplinary fields of geochemistry, oceanography, sedimentology, mineralogy, and geo(micro)biology with a particular emphasis on geochemical and isotope-based approaches to redox reconstructions, element cycling, and paleoenvironmental modeling. We welcome studies addressing the evolution of early life habitats, biomineralization, and paleobiological responses during intervals of profound environmental and climatic change, highlighting the links between Earth's chemical evolution and life.

Minerals are formed in great diversity under Earth surface conditions, as skeletons, microbialites, speleothems, or authigenic cements, and they preserve a wealth of geochemical, biological, mineralogical, and isotopic information, providing valuable archives of past environmental conditions. Interpretion of these archives requires fundamental understanding of fluid-rock interaction processes, but also insights from the geological record.

In this session we welcome oral and poster presentations from a wide range of research of topics, including process-oriented studies in modern systems, the ancient rock record, experiments, computer simulations, and high-resolution microscopy and spectroscopy techniques. We intend to reach a wide community of researchers sharing the common goal of improving our understanding of the fundamental processes underlying mineral formation, which is essential to read our Earth’s geological archive.

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

- Isotopologues of carbon dioxide (CO2), water (H2O), methane (CH4), carbon monoxide (CO), oxygen (O2), carbonyl sulfide (COS), and nitrous oxide (N2O)
- Novel tracers and biological analogues
- Polyisotopocules including "clumped isotopes"
- Non-mass-dependent isotopic fractionation and related isotope anomalies
- Intramolecular stable isotope distributions ("isotopomer abundances")
- Quantification of isotope effects
- Analytical, methodological, and modelling developments
- Flux measurements

Human activities on land (LULCC) shape climate by altering land-atmosphere fluxes of carbon, water, energy, and momentum. An increasing focus on land-based climate mitigation and adaptation strategies to meet more stringent targets has expanded the range of land management practices considered specifically for their potential to alter terrestrial carbon cycling or mediate favorable environmental conditions. This focus has also called attention to potential tradeoffs between climate-centric aspects of LULCC and its influences on biodiversity, hydrology and other environmental factors. Advancements in modeling and measurement techniques are opening new possibilities to better describe LULCC and its effects on the Earth system at multiple temporal and spatial scales. This session welcomes all contributions aimed at furthering our understanding of LULCC in the Earth system, including those addressing LULCC effects on carbon, climate, hydrology, and/or biodiversity, and aims to present studies that can inform adoption of appropriate land-based strategies for climate mitigation, adaptation, and ecosystem restoration.

Forest ecosystems face unprecedented pressure, with about one hectare of tropical forest lost or degraded every second, and over half destroyed since the 1960s (IUCN, 2021). While deforestation is easier to detect, forest degradation is harder to monitor but often causes greater losses of key ecosystem services (Qin et al., 2021). Climate change further intensifies degradation drivers, shifting forests from carbon sinks to carbon sources; in Europe alone, 168 million tons of CO₂-equivalent are lost annually due to climate-induced disturbances (Seidl et al., 2014).
Nature-based solutions (NBS), such as forest landscape restoration (FLR), provide vital opportunities to reverse these trends and restore ecological, social, climatic, and economic benefits. Major international commitments, including the Bonn Challenge and the UN Decade on Ecosystem Restoration, underscore the urgency of scaling restoration. At the regional level, the EU has launched research and innovation programs, such as Interreg CE-RENFORCE and H2020-SUPERB, to address the societal, economic, and policy dimensions of forest degradation and restoration.
Despite such efforts, forest degradation remains insufficiently understood due to inconsistent definitions, transboundary impacts, and limited monitoring tools. This session aims to advance knowledge by gathering insights into monitoring approaches, stakeholder perspectives, and policy dimensions of NBS and FLR under climate change. We welcome contributions on:

Modelling and predicting forest degradation drivers.
Impacts of degradation on ecosystem services.
Stakeholder perspectives and policy initiatives for NBS in FLR.
Innovative, cross-scale restoration strategies, including co-benefits and resilience under climate change.
IUCN (2021) Deforestation And Forest Degradation. IUCN Issues Brief. February 2021. Available at: https://iucn.org/sites/default/files/2022-04/deforestation-forest_degradation_issues_brief_2021.pdf
Qin Y, Xiao X, Wigneron JP, et al (2021) Carbon loss from forest degradation exceeds that from deforestation in the Brazilian Amazon. Nature Climate Change 2021 11:5 11:442–448.
Seidl R, Schelhaas MJ, Rammer W, Verkerk PJ (2014) Increasing forest disturbances in Europe and their impact on carbon storage. Nat Clim Chang 4:806–810.

Drylands, covering more than 40% of the Earth's land surface, are water-limited regions where evaporation exceeds precipitation. They are home to over a third of the world’s population, serve as reservoirs of carbon that regulate global trends and variability in atmospheric CO2, represent a key source to the global dust cycle, and host diverse endemic plants and animals. Drylands are vulnerable to climate and land-use change, and these pressures are expected to amplify the severity of climate extremes. At the same time, the extent of drylands is projected to expand, as climate change intensifies aridity, triggering abrupt ecosystem changes, which could affect services supporting local livelihoods. Yet, much about dryland ecosystem dynamics remains poorly understood, in part because of the importance of rapid-onset and highly localized events, emphasizing the need for improved understanding of dryland processes and their response to global change. Thus, developing integrated tools for assessing and monitoring dryland ecosystems represents a high research priority.

This session presents studies that advance our understanding of ecosystem dynamics in drylands, their role in carbon, water, and nutrient cycling, and the implications for ecosystem resilience under current and future global change. Topics of this session include (i) novel remote sensing approaches and applications for drylands, focusing on surface component mapping and monitoring, (ii) investigations on interactions among dryland ecology, hydrology, and climatology; (iii) presentation of the development or application of novel approaches to quantify and characterize dryland carbon-water-ecosystem interactions across space and time; and (iv) addressing challenges such as temporal and spatial variability and heterogeneity, pulse-driven dynamics, and measurement and modeling needs specific to drylands.

Oxidation of peat organic carbon is a critical determinant of greenhouse gas emissions from peatland ecosystems. This session aims to bridge the gap between biogeochemical processes at the pore scale and their environmental impacts at the ecosystem scale. At the heart of peat carbon oxidation are microorganisms that act on molecular carbon substrates, driving biogeochemical reactions at a microscale. These microbial processes are fundamental, yet they operate on a scale that poses challenges for direct observation and measurement. Our current methodologies allow us to measure processes at intermediate scales, providing valuable data on carbon turnover and peatland dynamics. However, there remains a significant challenge in inferring processes at the microscale and extrapolating or linking these drivers to the ecosystem scale, on which the implications of carbon emissions and climate change are most profound.
This scientific session will focus aims to integrate across the multiple scales of peat carbon oxidation. We will explore:
Microscale Processes: Understanding the role of biogeochemistry and microorganisms in peat decomposition and the processes that determine peat carbon oxidation potentials and rates.
Intermediate-Scale Measurements: Applying techniques and methodologies to measure carbon turnover and emissions, the insights they provide in underlying processes, and techniques for upscaling.
Challenges in Upscaling: Addressing the links between small-scale processes and ecosystem-scale emissions. This includes modeling approaches and integrative methods to connect scales.

Solicited author:
Dominik Zak

This session calls for contributions from all disciplines and inter- and trans-disciplinary collaborations that are addressing complex problems of effects of climate change and environmental degradation on human, animal, and ecosystems health. These may include, but are not limited to, data analysis and modelling approaches and data- and model-based solutions, indicators development, nature-based solutions, wellbeing-centered and other planetary health interventions. Likewise, the contributions can provide better understanding of or insights into wide range of problems, from air or water pollution or biodiversity loss, to human, animal, and environmental health issues like infectious and zoonotic diseases, or plastic pollution and antimicrobial resistance, driven by climate change or environmental degradation.

Measurements, monitoring and experiments are the basis of hydrological science. However, making these measurements is time-consuming, often financially expensive and not without risk. What do we need to measure, how do we need to measure it and where, to push the boundaries of our science? Where are observational gaps and how do we overcome them? This session aims to celebrate current pioneering work in field hydrology, new promising methods and courageous approaches, and to show the importance of field data for advancing hydrology.

A robust representation of terrestrial carbon, nitrogen, and water cycles requires a fundamental understanding of biosphere-atmosphere interactions, particularly in the context of a rapidly changing climate. However, a significant challenge arises from the mismatch that occurs when carbon, water, or nitrogen fluxes are measured or modelled at different spatio-temporal scales. Multiple processes determine how mass and energy exchanges scale from the leaf, to the whole plant, to the ecosystem, and eventually to the globe. Despite the evolution of Earth system models to incorporate increasingly complex processes across these scales, uncertainties persist due to these mismatches. The unprecedented rate of climate change, along with the increasing frequency and intensity of extreme events, further complicates our ability to robustly formulate mechanistic underpinnings of biogeochemical processes across scales.
The increasing volume of data at multiple scales—from leaf-level measurements (e.g., gas exchange), tree-level measurements (e.g., sap flow and dendroecology), ecosystem-level measurements (e.g., eddy covariance towers, UAVs, aircraft), to Earth observation from space—presents new opportunities to address these challenges. This session invites studies that improve our overall understanding of biosphere-atmosphere interactions by addressing the mismatches across different temporal and spatial scales and integrating these insights into modeling strategies. We particularly encourage contributions that explore the effects of climate extremes (e.g., drought, heatwaves, excess rainfall, winter warming) on carbon, nitrogen, and water fluxes. In addition to empirical multi-scale observations, we welcome research that delves into data-driven diagnostics and constraints for model evaluation, data-driven parameterisations in mechanistic models, and the development of data-driven/hybrid modelling strategies (i.e., seamless fusion of data-driven approaches and mechanistic models) for an integrated understanding of carbon, nitrogen, and water fluxes across scales.

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

This limited observational base gives rise to high uncertainty regarding the future terrestrial carbon sink. Many questions need answer to determine if this negative feedback to climate change will be sustained under future environmental changes, or whether increases in autotrophic respiration or carbon turnover might counteract it, for example through accelerated tree mortality or more frequent and more severe disturbance events (e.g. drought, fire, insect outbreaks) Shifts in the dynamics of plant mortality, establishment, and growth are expected to significantly influence forest composition.

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

Soil carbon (C) and nitrogen (N) cycling are central to soil functions such as climate regulation, nutrient supply, water retention, and ecosystem resilience. Management practices strongly influence these processes, shaping the capacity of soils to store carbon, regulate greenhouse gas emissions, and sustain productive ecosystems under increasing environmental pressures.

This joint session focuses on soil C and N cycling and related soil functions and processes, with particular emphasis on two soil domains that remain comparatively understudied: grassland soils and subsoils.

Contributions addressing grassland soils examine how management and restoration practices such as grazing regimes, fertilisation strategies, legumes, and silvopastoral systems, affect soil C sequestration, N cycling, and greenhouse gas emissions, and how these processes respond to broader drivers such as climate variability and grassland degradation.

Studies focusing on subsoils (below ~30 cm or the B-horizon) explore deep soil C and N dynamics, soil physical properties, soil–plant–atmosphere interactions, and the role of subsoils in long-term carbon storage, nutrient and water regulation, and ecosystem resilience. By integrating research across soil depths and land-use systems and managements, this session provides a holistic view of how management influences soil functions relevant to climate change mitigation and sustainable land management.

Our ability to understand biogeochemical cycles of carbon, nitrogen and phosphorus and other elements in aquatic ecosystems as well as biotic evolution and ecosystem functioning has evolved enormously thanks to advancements in in situ sensor measurements, laboratory techniques and predictive models. The aim of this session is to demonstrate how this methodological advancement improves our understanding of coupled hydrological, biogeochemical and ecological processes in aquatic environments and how it decodes faunal and ecosystem functional responses. In particular, our session focuses on improving the identification and quantification of the sources, delivery pathways, transformations and environmental fate of carbon and organic matter, nutrients, sediments and emerging contaminants in aquatic environments. Additional emphasis will be placed on biogeochemical interactions affecting aquatic organisms. In this multidisciplinary session, we welcome presentations on applications of novel techniques to improve our understanding of aquatic environments, , their biotic evolution, and robust data-driven and modelling approaches for advanced processing of aquatic biogeochemical data. As hydrological, biogeochemical, and ecological processes undergo accelerated change, this session welcomes also studies presenting approaches and tools to monitor, model, and predict water quality and sensitivity of aquatic ecosystems to global change and human disturbance.

Climate and environmental changes have long shaped the terrestrial ecosystems, biodiversity patterns, species dispersal, and human societies across timescales from deep time to the present and into the future. Variability in hydroclimatic conditions, temperature regimes, vegetation structure, fire dynamics, and water availability have influenced the distribution of terrestrial life forms, extinctions and adaptations, large-scale migrations and settlements, evolutionary innovations, ecosystem structure, and development of complex societies. For example, in the Eurasian arid and semi-arid regions connected to the Silk Road, climate variability affected exchange networks, mobility, and civilisational trajectories. Alongside the accelerating climate impacts, modern human activities have added unprecedented pressures to biodiversity and natural habitats.

This session explores climate-ecosystem interactions across space and time, integrating research on vegetation and fauna (including humans), and the broader aspects of ecosystem feedbacks and societal adaptations. We welcome interdisciplinary contributions integrating climate science, paleoecology, evolutionary biology, archaeology, history, genetics, geography, conservation science, and proxy-based and modeling approaches. Topics of interest include,

- Species extinctions, adaptations and the ecological impacts
- Vegetation and biome dynamics
- Biodiversity changes
- Fire and disturbance regimes
- Habitat degradation
- Hominin dispersal and habitat dynamics
- Climate-human-landscape interactions
- Agricultural adaptations
- Environmental influences on trade and exchange systems, including Silk Road contexts.

By bridging past, present, and future perspective, this session aims to foster cross-disciplinary dialogue and collaboration on the intertwined histories and futures of climate, life, and society.

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.

Tree rings are one of nature’s most versatile archives, providing insight into past environmental conditions at annual and intra-annual resolution and from local to global scales. Besides being valued proxies for historical climate, tree rings are also important indicators of plant physiological responses to changing environments and of long-term ecological processes. In this broad context we welcome contributions using one or more of the following approaches to either study the impact of environmental change on the growth and physiology of trees and forest ecosystems, or to assess and reconstruct past environmental change: (i) dendrochronological methods including studies based on tree-ring width, MXD or Blue Intensity, (ii) stable isotopes in tree rings and related plant compounds, (iii) dendrochemistry, (iv) quantitative wood anatomy, (v) ecophysiological data analyses, and (vi) mechanistic modeling, all across temporal and spatial scales.

The interactions between soil, plants, the atmosphere, and human activities are of greatest importance for the sustainable management and conservation of ecosystem functions and services. Terrestrial ecosystems are increasingly threatened by global climate change and human activities, which have complex and multifaceted impacts. To predict future changes and develop strategies for sustainable management, it is necessary to understand the impacts and processes involved. A key challenge in ecosystem research is to capture the complexity of these interactions. Simplified experimental approaches and long-term observations often focus on a limited number of variables. This makes it difficult to evaluate the system as a whole. To address this complexity, a variety of advanced experimental and observational platforms is available. These include lysimeters, ecotrons, remote and in-situ sensing technologies, and data-driven and model-based approaches. This session focuses on how ecosystems respond to climate change and other anthropogenic influences. It aims to promote studies that involve lysimeters and ecotrons but is not limited to these methods. We welcome contributions that integrate different approaches to the study of ecosystem processes are very welcome, as long as they are related to climate change and anthropogenic disturbances. Topics covered include, but are not limited to:
• Research on the functioning of ecosystems and ecosystem services
• Studies on water and nutrient transport processes and greenhouse gas fluxes within the soil-plant-atmosphere continuum
• Approaches to integrating observations across different scales, from small experimental setups to larger landscape or regional studies
• Comparative studies on different measurement and modelling approaches for assessing ecosystem processes
• Investigations of the interactions between climate change, human activities, and ecosystem dynamics

The study of nitrogen (N) processes in soils has a long and distinguished history. Recent research efforts have targeted the direct quantification of N turnover in the soil plant atmosphere system across scales. Nevertheless, methodological constraints, the high spatial and temporal variability of soil N transformation, and the multitude of interacting factors determining N availability and loss from soils presents significant challenges that make accurate quantification difficult, thereby limiting our quantitative understanding of the N turnover.
Although the factors controlling N turnover in soils are relatively well established under laboratory conditions, transposing these relationships to the field and landscape scales remains a significant challenge. The absence of data-sets collected in-situ impedes the validation of N processes, such as mineralization and denitrification simulated via process-based models, thereby rendering their results at field and regional scales highly uncertain. However, current ecosystem management challenges require accurate predictions of N fate to enable sustainable management that minimizes environmental losses.

We invite contributions from the following fields:
• Methodological advances in measuring and modelling of soil N processes, spanning from the micro- to the landscape scale;
• Measurements of N fluxes including specific loss pathways under field or field-like conditions with a focus on identifying controlling factors;
• Comparative studies demonstrating/evaluating novel approaches to constrain N turnover such as incubation under He/O2 atmosphere, 15N-tracer technique, N2O isotopologue approaches or other innovative methods;
• Process-based modelling of soil N processes at various scales;
• Linking nitrogen transformation rates to the function and structure of the soil microbial community.

Highly diverse soil biotic communities are central drivers of biogeochemical processes, and soil biodiversity as a “hot topic” has been raising political interest. We now increasingly understand the diversity, composition and even functional profiles of many soil taxa, still, the integration of physiological functions, community interactions and functional group composition into biogeochemical processes in heterogeneous soil systems remains limited due to methodological challenges. Developing fields of –omics, micro-/spectroscopy, isotope labelling and improved biomarker interpretations allow direct analyses of the activity of microorganisms and fauna in soil, contributing important novel perspectives in soil science. These emergent approaches are critical to predict how environmental changes modifies biogeochemical processes, as climate change, agricultural practices and pollutants threatens soil biodiversity. Our session presents research exploring soil biotic dynamics from individuals to complex communities with a focus on their impact on soil carbon and nitrogen cycling. The impact of environmental change on the functions of diverse biotic groups is explored with an exciting range of novel techniques. Beside a focus on soil microbial dynamics, understudied groups including protists, soil fauna and diverse trophic interactions are highlighted.