Since the launch of the first Earth Resources Technology Satellite 1 in 1972, land imaging technology has evolved rapidly and transformed science research innovation. The U.S. Geological Survey (USGS) is partnering with U.S. Federal agencies, incorporating input from state/local, academic, industry, and international communities, to document current usage and benefits, and improvement needs for future land imaging observation data and products. The European Commission in collaboration with the European Space Agency is also engaged in a continuous collection of user needs to drive the implementation of its programme. This includes feedback from users but also considering emerging needs from changes in society, policies and technologies.

These activities promote a needs-driven, prioritized investment decision process for land imaging systems, products, and services to better serve the broad land imaging community. This session will provide an overview of the current landscape of land imaging capabilities, applications, user needs for future systems, and the future landscape of land imaging including the rapidly expanding commercial sector.

This session will highlight activities within U.S. Federal agencies, academic, state/local, and international communities, and within the European Union institutions, agencies, including the European Space Agency and EU Member States.
We also invite submissions showcasing new and emerging multi-disciplinary land imaging applications, technology trends, and future needs and opportunities.

Terrestrial (semi-)natural and managed ecosystems like forests, grasslands, croplands and wetlands are important sources and/or sinks for greenhouse gases (GHGs: CO2, CH4, N2O) as well as for other trace gases (VOCs, NH3, NO, HONO, Rn, He, etc.). Soils sustain complex patterns of life and act as biogeochemical reactors. Production and consumption of gases and their transport in the soil result in typical patterns of gas concentrations that play a fundamental role affecting many soil functions, such as root and plant growth, microbial activity, and stabilization of soil organic carbon. Plants can contribute to ecosystem exchange by uptake and transport of soil-produced gases to the atmosphere, in-situ production and consumption of gases in plant tissues, and alternation of carbon- and nitrogen-turn-over in adjacent soil. However, the contribution of these individual processes to the net ecosystem GHGs exchange is still unclear and seems to depend on many aspects as plant/tree species, ecosystem type, soil type and conditions, environmental parameters and seasonal dynamics.
Due to the simultaneous influence of various environmental drivers and in case of managed land also management activities, the flux patterns in soil-plant-atmosphere systems are often complex and difficult to attribute to individual drivers. However, it is clear that Interactions between soil, vegetation and the atmosphere exert a crucial role controlling the global budget of these gases and need to be well understood to make any predictions for future.
The session addresses experimentalists and modellers working on trace gas fluxes and their dynamics, production and consumption processes, transport mechanisms and interactions in terrestrial ecosystems at any relevant scale, and from the full climatic and hydrological ecosystem range. We welcome also contributions presenting methodological aspects, development and application of new devices and methods, and modelling studies that seek to integrate our understanding of trace gas exchange in terrestrial ecosystems.

Public information:
EGU this year is different than it used to be. We will be able to use the “Sharing Geoscience Online” platform to present and exchange about our research data and results.
But EGU is not only sharing scientific content, but it is also meeting people. We always had session dinners in our session, where people could meet, have a drink, and exchange ideas about science and life in general.

We want to continue this tradition.
We will have a “Session-Dinner”-at-home online on Thursday, May 7, 19:00 (Vienna Time)

If you are interested in joinnig us, you are welcome - please let me know, and I ll share the link:

Martin.Maier@bodenkunde.uni-freiburg.de

Kind regards

Martin

From pole to pole, peatlands contain up to 30% of the world’s soil carbon pool, illustrating their important role in regulating the global carbon cycle. Currently, peatlands are under various pressures such as a changing climate or nutrient loading with unknown consequences for their functioning as carbon sinks and stores, including the uptake or release of the greenhouse gases carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).

However, it is not clear how the carbon reservoir will react to these pressures and how vulnerable or resilient these ecosystems are. Tipping points, thresholds, and system state changes are often referred to in the literature, but how much do we really know about these in a peatland context? This session will focus on the observed or predicted changes on the biogeochemistry of natural peatlands, caused by external pressures such as climate change, fire or nutrient loading.

We invite studies concentrating, for example, on the effects of climate change, nutrient loading or fire on GHG or nutrient dynamics, peatland vegetation, atmosphere-biosphere interactions or carbon stock changes. Field observations, experimental, and modelling studies of both high- and low-latitude peatlands are welcomed.

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

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

Shorter return period of climate and hydrological extremes has been observed in the changing climate, which affects the distribution and vitality of ecosystems. In many regions, available water is a crucial point of survival. Risk can be enhanced by the exposure and/or by the vulnerability of the affected ecosystem as well as by land use/land cover change.
The session should provide a multidisciplinary platform for sharing experiences and discussing results of local and catchment scale case studies from a wider range of relevant fields such as
• observed impacts and damage chains in natural and agricultural ecosystems induced by droughts and intense rainfall events;
• correlation between the underlying environmental factors (e.g. climate, water storage capacity of soil) and the distribution/vitality of ecosystems;
• integrated application or comparison of databases and methods for the identification and complex assessment of ecosystem responses to abiotic stress factors;
• expected tendencies of abiotic risk factors affecting and limiting the survival of the vulnerable species.
Contributions are encouraged from international experiences, ongoing research activities as well as national, regional and local initiatives.

Observations and simulations of the terrestrial carbon and water budget are fundamental to understanding biosphere-atmosphere interactions under a changing climate. A wide range of processes, covering various spatial and temporal scales, influence the response of terrestrial carbon fluxes (NEE, GPP, TER, fires, methane, lateral export) to changes in land and atmospheric moisture availability. The vegetation and soils also contribute to regulating land-atmosphere moisture fluxes (evapotranspiration, precipitation), which in turn feeds back to the water cycle and the climate system. Observations or modeling assumptions made at different spatial and temporal resolutions also pose new challenges in terms of scaling and uncertainty quantification.

This session aims to synthesize our current understanding and identify knowledge gaps and transferability across scales, We encourage contributions exploring carbon-water interactions from multiple perspectives (remote-sensing, experimental, modelling) and covering all types of biomes (boreal, temperate and tropical forests, grasslands, wetlands, …). Contributions might include for example: 1) disentangling the impact of co-varying drought-driven changes to soil moisture, vapour pressure deficit, or temperature on land carbon fluxes, 2) using in-situ or satellite observations to evaluate or improve the representation of water-carbon interactions and biological processes in models, 3) developing and implementing new representations of plant and ecosystem responses to land and atmospheric moisture stress (e.g. through plant hydraulics, optimality approaches, etc.) and 4) scaling carbon- water interactions from the leaf-level to the global scale and bridging the gap between data streams taken at different temporal and spatial scales (e.g. using modeling, theoretical or statistical approaches).

Solicited speaker: Alexandra Konings, Stanford University

Public information:
Observations and simulations of the terrestrial carbon and water budget are fundamental to understanding biosphere-atmosphere interactions under a changing climate. A wide range of processes, covering various spatial and temporal scales, influence the response of terrestrial carbon fluxes (NEE, GPP, TER, fires, methane, lateral export) to changes in land and atmospheric moisture availability. The vegetation and soils also contribute to regulating land-atmosphere moisture fluxes (evapotranspiration, precipitation), which in turn feeds back to the water cycle and the climate system. Observations or modeling assumptions made at different spatial and temporal resolutions also pose new challenges in terms of scaling and uncertainty quantification.

This session aims to synthesize our current understanding and identify knowledge gaps and transferability across scales, We encourage contributions exploring carbon-water interactions from multiple perspectives (remote-sensing, experimental, modelling) and covering all types of biomes (boreal, temperate and tropical forests, grasslands, wetlands, …). Contributions might include for example: 1) disentangling the impact of co-varying drought-driven changes to soil moisture, vapour pressure deficit, or temperature on land carbon fluxes, 2) using in-situ or satellite observations to evaluate or improve the representation of water-carbon interactions and biological processes in models, 3) developing and implementing new representations of plant and ecosystem responses to land and atmospheric moisture stress (e.g. through plant hydraulics, optimality approaches, etc.) and 4) scaling carbon- water interactions from the leaf-level to the global scale and bridging the gap between data streams taken at different temporal and spatial scales (e.g. using modeling, theoretical or statistical approaches).

Solicited speaker: Alexandra Konings, Stanford University

In this session we focus on GHG emissions and an understanding of how management activities and different land use combinations modify the GHG exchanges of different landscape mosaics. A particular emphasis will be placed on how to parcel different management practices and land uses together to provide an optimum configuration that minimizes GHG emissions. We also welcome contributions that report on the GHG mitigation potential of different management practices or land uses. Given the potential role of forests in GHG offsetting this session also seeks to bring together scientists working on the exchange of CO2, CH4 and N2O in forest ecosystems. We also welcome contributions from conventional flux measurements on cropland, grazing systems, and forests, as well as innovative approaches for gas sampling and small scale/on-farm micrometeorological measurements, together with satellite and modelling studies that seek to integrate our understanding of landscape GHG exchanges. We further invite contributions that aim at combining measurements with modelling approaches, and/or those that are trying to disentangle how management practices modify the processes responsible for GHG production and consumption at the farm or ecosystem level. This session also will benefit from contributions from FACCE ERA-GAS programme.

Public information:
This session is focused on land use mosaics and greenhouse gas emissions.

We have a varied programme, including methane uptake by forest soils, re-wetting effects on nitrous oxide emissions, solar panel forests and hedgerow carbon sequestration, so there is something for everyone!

I would encourage you to look at the abstracts and presentations for this session so that we can have an informed and lively discussion.

Please join us on Thursday 7 May, from 1400-15.45

Bruce Osborne

The assessment of forest vulnerability and resilience in the sight of global ecological, social and economic changes is a relevant issue. In recent decades, forest vulnerability is rapidly increasing worldwide and forecasting changes in tree health is becoming a challenge. Forest dieback episodes have been recorded in all biomes affecting different tree and shrub species. These dieback cases are revealing the high vulnerability of some species, particularly conifers, manifested as a loss in tree vigour, growth decline and sometimes tree death. Tree mortality commonly involves multiple, interacting factors, ranging from drought to insect pests and diseases, often making the determination of a single cause unrealistic. The need of understanding and predicting changes in tree mortality, growth and recruitment in response to dieback is essential to improve vegetation and C cycle models.
There is a common agreement on the key role of interdisciplinary research and the combined use of complementary tools to improve the monitoring and projection of forest vulnerability and dieback.
This session focuses on efforts to improve our understanding on: i) causes and mechanisms related to forest vulnerability and dieback; ii) potential changes in tree species composition, forest structure and extent of dieback under current and future climate change scenarios; iii) evaluation of which functional anatomical and hydraulic traits make some tree species or stands and tree populations more prone to environmental-induced dieback and decline IV) assessment of the role and interaction of insect disease and other abiotic factors on mortality; V) possible contribution of novel methods and approaches in quantitative wood anatomy to evaluate plant adaptive capability and identify early-stress indicators; VI) how trees die from drought and how to quantitatively assess tree mortality rates and the magnitude of tree mortality episodes associated to climate change events.
Contributions will focus on an integrated multi-scale (from cells to plant communities, ecosystems and global approaches), multi-temporal (from tree-ring series analysis to xylogenesis and long-term forecasting) and interdisciplinary (microscopy and individual plant physiology to remote sensing) frameworks.

Land use and land cover change (LULCC), including land management, has the capacity to alter the climate by disrupting land-atmosphere fluxes of carbon, water and energy. Thus, there is a particular interest in understanding the role of LULCC as it relates to climate mitigation and adaptation strategies. Much attention has been devoted to the biogeochemical impacts of LULCC, yet there is an increasing awareness that the biogeophysical mechanisms (e.g. changes in surface properties such as albedo, roughness and evapotranspiration) should also be considered in climate change assessments of LULCC impacts on weather and climate. However, characterizing biogeophysical land-climate interactions remains challenging due to their complexity. If a cooling or a warming signal emerges depends on which of the biogeophysical processes dominates and on the size and pattern of the LULCC perturbation. Recent advances exploiting Earth system modelling and Earth observation tools are opening new possibilities to better describe LULCC and its effects at multiple temporal and spatial scales. This session invites studies that improve our general understanding of climate perturbations connected to LULCC from both biogeophysical and biogeochemical standpoints, and particularly those focusing on their intersection. This includes studies focusing on LULCC that can inform land-based climate mitigation and adaptation policies. Both observation-based and model-based analyses at local to global scales are welcome.

Carbon allocation is a key process in ecosystems: it is coupled with plant growth, fuels metabolism and plays a crucial role for carbon sequestration in standing biomass and soil organic matter. While the importance of carbon allocation for plant and ecosystem functioning and the carbon balance is widely recognized, we still lack a comprehensive understanding of the underlying mechanisms, responses to global changes and wider biogeochemical implications. Open questions include: 1) what drives carbon allocation in plants and ecosystems?; 2) what is the fate of newly assimilated carbon?; 3) what determines the allocation of nonstructural carbon to growth, metabolism and storage?, 4) how does carbon allocation affect nutrient and water relations in plants and ecosystems?; and 5) how do allocation patterns change under changing environmental conditions and what are the consequences for biogeochemical cycles? This session invites contributions from observational, experimental and modelling studies.

The need to predict ecosystem responses to anthropogenic change, including but not limited to changes in climate and increased atmospheric CO2 concentrations, is more pressing than ever. Global change is inherently multi-factorial and as the terrestrial biosphere moves into states without a present climate analogue, mechanistic understanding of ecosystem processes and their linkages with ecosystem function is vital to enable predictive capacity in our forecast tools.

This PICO session aims to bring together scientists interested in advancing our fundamental understanding of vegetation and whole-ecosystem processes. We are interested in contributions focused on advancing process- and hypothesis-driven understanding of plant ecophysiology, biodiversity and ecosystem function. We welcome studies on a range of scales from greenhouse and mesocosm experiments to large field manipulative experiments and process-based modelling. We encourage contributions of novel ideas and hypotheses in particular those from early stage researchers and hope the session can create an environment where such ideas can be discussed freely.

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. Observed, and likely future, changes in vegetation structure and functioning are the result of interactions of these processes with atmospheric carbon dioxide concentration, climate and human activities. The quantification and assessment of such changes has proven extremely challenging because of a lack of observations at large scales and over the long time periods required to evaluate trends.

Thus, our current understanding of the environmental controls on vegetation dynamics and properties, and, in turn, their impact on carbon stocks in biomass and soils, is limited. The behaviour of vegetation models regarding many of the processes mentioned above remains under-constrained at scales from landscape to global. This gives rise to high uncertainty as to whether the terrestrial vegetation will continue to act as a carbon sink under future environmental changes, or whether increases in autotrophic respiration or carbon turnover might counteract this negative feedback to climate change. For instance, accelerated background tree mortality or more frequent and more severe disturbance events (e.g. drought, fire, insect outbreaks) might turn vegetation into carbon sources. Likewise, understanding how these shifts in dynamics will influence forest composition is crucial for long-term carbon cycle projections.

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

This session explores the potentials and limitations of various remote sensing applications in forestry, with the focus on the identification and integration of different methodologies and techniques from different sensors and in-situ data for providing qualitative and quantities forest information.
In general, remote sensing allows examining and gathering information about an object or a place from a distance, using a wide range of sensors and platforms. A key development in remote sensing has been the increased availability of data with very high temporal, spatial and spectral resolution. In the last decades, several types of remote sensing data, including optical, multispectral, radar, LiDAR from terrestrial, UAV, aerial and satellite platforms, have been used to detect, classify, evaluate and measure the earth surface, including different vegetation cover and forest structure. For the forest sector, such information allows efficient quantification of the state and monitoring of changes over time and space, in support of sustainable forest management, forest and carbon inventory or for monitoring forest health and their disturbances. Remote sensing data can provide both qualitative and quantitative information about forest ecosystems. In a qualitative analysis, forest cover types and species composition can be classified, whereas the quantitative analysis can measure and estimate different forest structure parameters related to single trees (e.g. DBH, height, basal area, timber volume, etc.) and to the whole stand (e.g. number of trees per unite area, spatial distribution, etc.). However, to meet the various information requirements, different data sources should be adopted according to the application, the level of detail required and the extension of the area under study. The integration of in-situ measurements with satellite/airborne/UAV imagery, Structure from Motion, LiDAR and geo-information systems offers new possibilities, especially for interpretation, mapping and measuring of forest parameters and will be a challenge for future research and application.

Fire is an essential feature of terrestrial ecosystems and an important component of the Earth system. Climate, vegetation characteristics, and human activity regulate fire occurrence and spread, but fires also feedback to them in multiple ways. The mechanisms of interactions between fire, land, atmosphere, and society are complicated and remain poorly understood quantitatively. This session welcomes contributions on all aspects of links between fire, biosphere, climate, and humans to share recent advances and foster interdisciplinary discussions. We encourage all abstracts that explore the role of fire in the Earth system at any temporal and spatial scale using modeling, field and laboratory observations, and/or remote sensing, with an emphasis on studies that advance our understanding on (1) impacts of fire on weather, climate, and atmospheric chemistry, (2) interactions between fire, biogeochemical cycles, land water and energy budgets, and vegetation composition and structure, (3) influence of humans on fire and vice versa (e.g., impact of fire on air and water quality, human health, and economy), (4) fire characteristics (e.g. fire duration, emission factor, emission height, smoke transport), (5) spatial and temporal changes of fires in the past, present, and future, (6) fire products and models, and their validation and error/bias assessment, and (7) analytical tools designed to enhance situational awareness among fire practitioners and early warning systems, addressing specific needs of operational fire behavior modeling.

Sustainable agriculture is needed to ensure that both present and future societies will be food secure. Current agricultural productivity is already challenged by several factors, such as climate change, availability and accessibility of water and other inputs, socio-economic conditions, and changing and increased demand for agricultural products. Agriculture is also expected to contribute to climate change mitigation, to minimize pollution of the environment, and to preserve biodiversity.
Assessing all these requires studying alternative land management at local to global scales and to assess agricultural production systems rather than individual products.
This session will focus on the modeling of agricultural systems under global change, addressing challenges in adaptation to and mitigation of climate change, sustainable intensification and environmental impacts of agricultural production. We welcome contributions on methods and data, assessments of climate impacts and adaptation options, environmental impacts, GHG mitigation and economic evaluations.

Monitoring and modeling of vegetation and ecosystem dynamics is fundamental in diagnosing and forecasting Earth system states and feedbacks. However, the underlying ecosystem processes are still relatively poorly described by Earth system models. Confronting terrestrial biogeochemical models at multiple temporal and spatial scales with an ever-increasing amount and diversity of Earth observation data is therefore needed.

To this end, the rapidly growing amount of satellite data has fostered the development of novel global Earth observation products of vegetation and ecosystem properties (such as sun-induced fluorescence SIF, microwave vegetation optical depth VOD, biomass, spectral plant traits, fuel moisture content, multi-sensor climate data records, new high-resolution products), which complement more traditional products like NDVI, LAI or fAPAR. In this session, we present the most recent advances in:

(1) the production of global land surface biophysical and biochemical variables from satellite observations;

(2) assessment of plausibility, validation and inter-comparisons of these products;

(3) their use in the development of data-driven models to estimate and analyze ecosystem processes;

(4) their use in studying global ecosystem dynamics related to climate variability and change;

(5) benchmarking and improvement of global vegetation models through statistical analysis and model-data integration techniques.


The latter may consider methodological foci or include applications related to the monitoring and modeling of terrestrial vegetation and ecosystem dynamics for timescales from days to decades, also including multiple data streams.

Globally, 10–20% of peatlands have been drained for agriculture or forestry emitting close to 5% of global anthropogenic CO2 emissions. Some European countries report more than 60% of their emissions from agriculture and land use, land use change and forestry (LULUCF) originating from drained organic soils, and the fate of South-East Asian peatlands is of global concern. Most peatland-rich countries address peatlands poorly in national emission reporting and climate change mitigation strategies.

Peatland restoration for conservation purposes can solve many problems related to drained peatlands and has been implemented for decades now. However, innovative mitigation measures that sustain economically viable biomass production while reducing negative environmental impacts including greenhouse gas (GHG) emissions, fire risk and supporting ecosystem services of organic soils are only currently studied. Management measures include, but are not limited to, productive use of wet peatlands, improved water management in conventional agriculture and innovative approaches in conservation-focused rewetting projects. Production systems with high water tables can generate food, feed, fiber, fuel and raw materials for chemical industry. A better understanding of ecosystem functioning and underlying processes is the basis for sustainable use of wet landscapes. Implementing these innovations in practice and integrating them into national GHG inventories remains a challenge.

We invite studies addressing all types of peatland management, i.e. agriculture, forestry and “classical” restoration, as well as their integration into GHG inventories. Work on all spatial scales from laboratory to national level addressing biogeochemical and biological aspects and experimental and modelling studies are welcome. Especially research on development of systems with details on commodities with viable value chains and income generation are of interest. Furthermore, we invite contributions addressing policy coherence and identifying policy instruments for initiating and implementing new management practices on organic soils.

This session is organized as a joined effort of Global Research Alliance “Peatland Management” working group, Greifswald Mire Centre, Thünen Institute and the WETSCAPES project (ESF/14-BM-A55-xxx/16) funded by the European Social Fund and the Ministry of Education, Science and Culture of Mecklenburg-Western Pomerania.

Human activities are altering a range of environmental conditions, including atmospheric CO2 concentration, climate, and nutrient inputs. However, understanding and predicting their combined impacts on ecosystem structure and functioning and biogeochemical cycles is challenging. 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. These model projections constrain the current mean state of the terrestrial biosphere, but they provide limited information on the sensitivity of ecophysiological, biogeochemical, and hydrological processes to environmental changes. Observational and ecosystem manipulation studies (e.g., Free-Air Carbon Dioxide Enrichment (FACE), nutrient addition or warming experiments) can complement modelling studies with unique insights and inform model development and evaluation. This session focuses on how ecosystem processes respond to changes in CO2 concentration, warming, altered precipitation patterns, water and nutrient availability. It aims at fostering the interaction between the experimental and modelling communities by advancing the use of observational and experimental data for model evaluation and calibration. We encourage contributions from syntheses of multiple experiments, model intercomparisons and evaluations against ecosystem manipulation experiments, pre-experimental modelling, or the use of observations from "natural experiments". Contributions may span a range of scales and scopes, including plant ecophysiology, soil organic matter dynamics, soil microbial activity, nutrient cycling, plant-soil interactions, or ecosystem dynamics.

Mountain forests significantly contribute to the habitability of mountain regions, reducing risk for people, infrastructure and resources suffering from natural hazards, including floods, debris floods, debris flows, snow avalanches and rockfalls. Mountain forests are, however, also highly sensitive to climate variability, potentially eroding their protection function under climate change. Since the 19th century, European and other countries in mountain regions have developed a variety of forest and landscape managing techniques for sustaining the protective function of forests. Those management techniques can be seen as are part of the European natural and technical heritage and are of high public interest. Yet, natural disturbances, changes in forest structure and biodiversity, and regeneration failure might pose substantial challenges to forest and landscape management. We thus need to increase our understanding of how the protective function of mountain forests is affected by climate change. The aim of the session consequently is to compile current knowledge on climate change impacts on mountain forests ecosystems and their protective function against natural hazards across the globe.
Potential topics might include the monitoring and modelling of changing disturbance regimes and their impacts on the protective functions of forests, regeneration and recovery failure of mountain forests, and the effects of human land use and changing societal demands on mountain forests and their protective forests. We hope to gain a broad overview on global mountain forest ecosystems in the context of protection against natural hazards.

Soil organic matter (SOM) dynamics play a major role in determining soil fertility, atmospheric CO2 concentrations and climate change adaptation. However, the relationship between soil C persitance and vulnerability under increasing atmospheric temperature and growing global population is poorly understood. Therefore better constraints on SOM pools and fluxes and their reaction to global change are required allowing to disentangle soil C persistence and vulnerability. This session focuses on empirical and modeling studies of soil carbon and its response to warming, and ecosystem vulnerability in different soil types. Contributions focusing on organic as well as mineral soils in contrasting climatic regions are welcome. They may include interdisciplinary research from experiments and observation networks collecting long term, geographically distributed data. International efforts working towards soil data harmonization and data-model sharing are also featured.

Climate changes can alter ecosystem processes and functioning, however these changes are difficult to predict due to multiple interactions and feedbacks between different processes and components within the system. Studies on single processes, e.g. at the soil, root or plant scale, can shed light into individual responses but are limited in their power to be up-scaled to the ecosystem level. Stable isotopes or other tracers can be used to scale information on processes on the soil, rhizosphere, vegetation and atmosphere exchange to the ecosystem level. Using natural or experimentally induced ecosystem responses to climate change drivers when combined with stable isotope labelling or other novel techniques can provide a critical link to elucidate interlinked responses to disturbances. This session invites contributions from studies that investigate ecosystem responses from the molecular and microbial to atmospheric scale, using novel techniques such as compound or position-specific stable isotope labelling. We welcome studies from experimental, as well as natural ecosystems.
Invited speaker: Dan Yakir

Ecosystem management in forests, croplands, grassland, mires, rangelands amongst others is a major driver of net greenhouse gas (GHG) exchange between an ecosystem and the atmosphere. Within this session we aim at better understanding on how management activities in terrestrial ecosystems modify the exchange of the three major GHGs: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). We are particularly interested in in-situ measurements (both short and long-term) of either a single GHG, or studies that jointly assess all three GHGs from managed ecosystems. Direct comparison studies of different managements or managed vs. unmanaged systems are encouraged. We further invite contributions that aim at combining GHG measurements with modeling approaches, and/or those that try to disentangle how management practices modify the processes responsible for GHG production/consumption at the plant, soil or ecosystem level. As an output if this session we anticipate, (1) learning about individual approaches currently being used to better understand the effects of management activities on GHG budgets, and (2) to compile information and develop standardized guidelines for existing and future studies allowing for direct comparison across systems.

Over 600 flux stations are presently operational as part of continental and national flux networks and under the umbrella of the FLUXNET global network, with multiple dozens more flux stations operating as smaller dedicated networks and standalone projects. A total of over 2100 flux tower locations had provided data in the past covering large portions of the globe.

In the last 10 years, multiple new highly advanced software, codes and routines to analyze various aspects of this wealth of flux and ancillary data were developed by individuals, research groups, regional and national networks. From raw-data processing over multi-method data cleaning, gap filling and flux partitioning to flux-footprint budgeting and bottom-up modeling, such advanced tools offer an unprecedented analytical power to the ecosystem flux community.

This session is designed to bring together scientists and developers who have developed such tools utilizing the latest in flux methodology, ecosystem measurements, new instrumentations, and modern computing, so as to provide an orientation map of available tools to ecosystem researchers, flux scientists and ecosystem modelers.

If you developed a tool or code that you think is useful for understanding ecosystem processes and that facilitates data processing, this is the right session to submit to.

Tropical ecosystems play an important role in the regional and global climate system through the exchange of greenhouse gases (GHGs), water and energy and provide important ecosystems services. However, increasing pressures from rapidly growing populations have resulted in intensive transformation of tropical landscapes resulting in deforestation, agricultural expansion, erosion and fire. Carbon-rich ecosystems such as peatlands and forests are particularly threatened, as deforestation and drainage alter their fluxes of dissolved organic carbon (DOC), carbon dioxide and methane. Across the tropics, land use impacts, in combination with climate change, are altering biogeochemical cycles and hydrology, highlighting the need for new observations and understanding that will support sustainable management in these ecosystems.

However, we are limited by both a lack of data and fundamental understanding of tropical landscapes and peatlands. In this session we welcome contributions that provide insights on how changes in climate and land use impact biogeochemical cycles and ecohydrology in the tropics. We invite work on pristine, degraded and agricultural ecosystems, including but not limited to forests, savannahs, oil palm plantations, peatlands, wetlands, lakes and rivers. At the site-level, we welcome studies including laboratory and field experiments, eddy covariance and flux measurements and process-based models. At larger spatial scales, we invite the application of earth observation and modeling tools including airborne and remote sensing products (i.e. LIDAR, SAR and Optical), forest mapping, calibration and validation of new tools, and large-scale simulations, including those addressing climate sensitivity, fire risk and disturbance. Finally, we encourage representation of all tropical regions, including South and Southeast Asia, Africa and the Americas.

Natural disturbances are a primary driver of forest dynamics, thus shaping their composition and structure, and determining succession trajectories.
With the multitude of functions and services simultaneously and increasingly required from forest ecosystems, it is crucial to improve our understanding of the impact of natural disturbances on forests, also in light of the potential alterations introduced by different global change drivers, mostly due to anthropogenic activities. Unprecedented disturbances, both in type and intensity, due to changes in disturbance regimes are occurring in many parts of the world.
Further attention is required to the many ways in which multiple disturbances (of biotic, abiotic and anthropogenic origin) interact with each other, thereby modifying the likelihood of occurrence and the effects of one another.
Despite an increasing awareness of the fundamental ecological role of natural disturbances, forest management still requires solid scientific input on how to increase the resistance and resilience of forests, and manage naturally disturbed landscapes to promote forest regeneration.
This complex situation calls for multi-scale, multi temporal, and multidisciplinary studies, taking advantage of field (in-situ) and remote sensing approaches, in order to capture the large heterogeneity and variability of the patterns and processes involved. In this session, we invite contributions from all fields in order to promote knowledge on disturbance ecology, to implement monitoring of forest recovery, and to promote sustainable forest management.

The world has been significantly transformed by human actions at least throughout the course of the Holocene with implications for ecological functioning, climate regulation, etc. Central to furthering understanding of the timing, extent and impact of these transformations is quantification of vegetation cover and land-use at local, regional and continental scales, and at centennial to millennial timescales. Recent accelerations in the intensity of human land use have been implicated for changes in biodiversity, however, relationships between land use change and diversity are complex and include important historical legacies. This session explores recent developments in, and applications of, the quantification of land-cover and land-use from palaeobotanical and palynological data in globally diverse landscapes. We welcome all contributions on methodological advances, and applications to historic and prehistoric long-term dynamics and drivers of land-use, anthropogenic land-cover and land-system change, as well as shifts in biodiversity patterns. These contributions may include pollen and other palaeobotanical approaches to land-use and land-cover change, archaeological and historical records and related palaeoecological data (e.g. palaeoentomological data), as well as modelling studies on anthropogenic land-cover change (ALCC) and climate-land use interactions.

This session contributes to the PAGES LandCover6k working group (http://pastglobalchanges.org/landcover6k). The primary goal of LandCover6k is to use global empirical data on past land-use and anthropogenic land-cover change to evaluate and improve Anthropogenic Land-Cover Change scenarios for earth system modellers (e.g. the World Climate Research Programme CMIP and PMIP initiatives). However, submissions do not need to be explicitly linked to this working group and we welcome abstracts with wider reaching themes spanning environmental responses to human activities, such as biodiversity loss and changes in ecosystem functioning.

Gross photosynthetic CO2 uptake is the single largest component of the global carbon cycle and a crucial variable for monitoring and understanding global biogeochemical cycles and fundamental ecosystem services. Nowadays routine measurements of the net biosphere-atmosphere CO2 exchange are conducted at the ecosystem scale in a large variety of ecosystem types across the globe. Gross photosynthetic and ecosystem respiratory fluxes are then typically inferred from the net CO2 exchange and used for benchmarking of terrestrial biosphere models or as backbones for upscaling exercises. Uncertainty in the responses of photosynthesis and respiration to the climate and environmental conditions is a major source of uncertainty in predictions of ecosystem-atmosphere feedbacks under climate change. On the other hand transpiration estimates both at ecosystem to global scales are highly uncertain with estimates ranging from 20 to 90 % of total evapotranspiration. The most important bottleneck to narrow down the uncertainty in transpiration estimates is the fact that direct measurements of transpiration are uncertain and techniques like eddy covariance measure only the total evapotranspiration.
During the last decade, technological developments in field spectroscopy, near surface remote sensing, including sun-induced fluorescence, isotope flux measurements and quantum cascade lasers have enabled alternative approaches for constraining ecosystem-scale photosynthesis, respiration and transpiration. On the other hand a variety of approaches have been developed to directly assess the gross fluxes of CO2 and transpiration by using both process based and empirical models, and machine learning techniques.
In this session we aim at reviewing recent progress made with novel approaches of constraining ecosystem gross photosynthesis, respiration and transpiration and at discussing their weaknesses and future steps required to reduce the uncertainty of present-day estimates. To this end we are seeking contributions that use emerging constrains to improve the ability to quantify respiration and photosynthesis processes, transpiration and water use efficiency, at scales from leaf to ecosystem and global. Particularly welcome are studies reporting advancements and new developments in CO2 and evapotranspiration flux partitioning from eddy covariance data, the use of carbonyl sulfide, stable isotopes approaches, and sun-induced fluorescence.

Urban greenspaces play a prime role in making city liable and natural. They are a vital part of the city on the way to achieve sustainable development. They have great values in offering ecosystem services, improving environmental quality and maintaining biodiversity. Smart allocation of greenspaces in the cities will optimize their values to enhance the adaptive capacity in the context of the climate change and anthropogenic processes. Due to competition for space in the urban region, the urban forests and urban greenspaces are vulnerable to the encroachments associated with the growth of the city and the damages linking to extreme weather.

This session aims to gather original viewpoints and bring up discussions concerning various opportunities and challenges in different areas of science of earth observations, environmental health in association with vegetation health, economy and industrialization, in particular, liking to urban greenspaces. innovative techniques and approaches are encouraged to be introduced to foster applications of remote sensing and GIS in contemporary practice. Urban greenspaces are expected to be assessed, monitored and managed by the means of remote sensing and GIS technologies and benchmark models. It is also encouraged to present and discuss the green indices, conceptual frameworks, implemented approaches, models and innovative techniques to make city smarter in greening. Outcomes of the comprehensive studies are essential to make the cities more adaptive in the context of climate change.

The rhizosphere is regarded as the soil compartment with the highest level of nutrient flux through a multitude of interactions between plants, soil, and (micro)biota. Roots and associated (micro)organisms interact with heterogeneous soil environments that provide habitats for biota on various scales. High metabolic activity and nutrient cycling can be observed from single root tips to whole root systems which makes the rhizosphere of central importance for ecosystem functioning.
The main knowledge-gaps in rhizosphere research are related to the difficulty in mechanistically linking the physical, chemical and biological processes, taking place at different scales (nm to cm) in the rhizosphere and to the challenge of upscaling these processes to the scale of the root system and the soil profile. The key for overcoming these knowledge gaps is to understand rates of matter flux, and to link the spatial arrangement of the different interconnected components of the rhizosphere with their temporal dynamics. This requires concerted efforts to combine methods from different disciplines like plant genomics, imaging, soil physics, chemistry and microbiology.
We welcome experimental and modelling studies on rhizosphere functioning that aim at revealing spatial gradients of e.g. functional biodiversity of microorganisms, uptake and release patterns by roots, soil structure modification by root growth (and vice versa) as well as feedbacks between those processes in order to improve our mechanistic understanding of emerging properties like water acquisition, nutrient cycling, plant health, soil structure development and feedbacks among them.

Viticulture is one of the most important agricultural sectors of Europe with an average annual production of 168 million hectoliters (54% of global consumption). The concept of “Terroir” links the quality and typicity of wine to the territory, and, in particular, to specific environmental characteristics that affect the plant response (e.g. climate, geology, pedology). The environmental factors that drive the terroir effect vary in space and time, as well as soil and crop management.
Understanding the spatial variability of some environmental factors (e.g. soil) is very important to manage and preserve terroirs and face the current and future issue of climate change. In this sense, it is important to stress that in the last decade, the study of terroir has shifted from a largely descriptive regional science to a more applied, technical research field, including: sensors for mapping and monitoring environmental variables, remote sensing and drones for crop monitoring, forecast models, use of microelements and isotopes for wine traceability, metagenome approach to study the biogeochemical cycles of nutrients.
Moreover, public awareness for ecosystem functioning has led to more quantitative approaches in evidencing the relations between management and the ecosystem services of vineyard agroecosystems. Agroecology approaches in vineyard, like the use of cover crops, straw mulching, and organic amendments, are developing to improve biodiversity, organic matter, soil water and nutrient retention, preservation from soil erosion.
On those bases, the session will address the several aspects of viticultural terroirs:
1) quantifying and spatial modelling of terroir components that influence plant growth, fruit composition and quality, mostly examining climate-soil-water relationships; 2) terroir concept resilience to climate change; 3) wine traceability and zoning based on microelements and isotopes; 4) interaction between vineyard management practices and effects on soil and water quality as well as biodiversity and related ecosystem services.

Soil organic matter (SOM) is well known to exert a great influence on physical, chemical, and biological soil properties, thus playing a very important role in agronomic production and environmental quality. Globally SOM represents the largest terrestrial organic C stock, which can have significant impacts on atmospheric CO2 concentrations and thus on climate. The changes in soil organic C content are the result of the balance of inputs and losses, which strongly depends on the processes of organic C stabilization and protection from decomposition in the soil. This session will provide a forum for discussion of recent studies on the stabilization and sequestration mechanisms of organic C in soils, covering any physical, chemical, and biological aspects related to the selective preservation and formation of recalcitrant organic compounds, occlusion by macro and microaggregation, and chemical interaction with soil mineral particles and metal ions.

The MacGyver session focuses on novel sensors made, or data sources unlocked, by scientists. All geoscientists are invited to present
- new sensor systems, using technologies in novel or unintended ways
- new data storage or transmission solutions sending data from the field with LoRa, WIFI, GSM, or any other nifty approach
- started initiatives (e.g., Open-Sensing.org) that facilitate the creation and sharing of novel sensors, data acquisition and transmission systems.

Connected a sensor for iPhone to an Arduino or Raspberri Pi? 3D printed an automated water quality sampler? Or build a Cloud Storage system from Open Source Components? Show it! New methods in hydrology, plant physiology, seismology, remote sensing, ecology, etc. are all welcome. Bring prototypes and demonstrations to make this the most exciting Poster Only (!) session of the General Assembly.

This session is co-sponsered by MOXXI, the working group on novel observational methods of the IAHS.

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, cross-disciplinary studies in human-landscape interaction provide valuable opportunities to learn from the past. This session is targeted at providing a platform for scientists with common interests in geomorphology and geoarchaeology and, in particular, the complex and integrated nature of the relationship between landforms, geomorphological processes and societies during the Anthropocene, and how this has developed over time at different spatial and temporal scales.

This session seeks related interdisciplinary papers and specific geomorphological or geoarchaeological case-studies that deploy various approaches and tools to address the reconstruction of former and present 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. We are inviting contributions that focus on the two-way interactions between geomorphological processes/landforms and human activity. These should show how the various factors of the physical environment interact with the Anthroposphere, and, in turn, how population and individuals may affect (and change) these factors. Furthermore, contributions may include (but are not limited to) insights about how people have coped with environmental disasters or abrupt changes; defining sustainability thresholds for farming or resource exploitation; distinguishing the baseline natural and human contributions to environmental changes. In this context, topics of different fields may be addressed in the session such as landform evolution, landscape sensitivity and resilience in the overall context of the interrelation between geomorphology and society, geohazards, geoheritage and conservation, geomorphological responses to (and evidence for) environmental change, and applied geomorphology. Moreover, issues of scale and hierarchies may be addressed, and methods and applications of dynamic rather than equilibrium ideas and metaphors. Ultimately, we would like to understand how strategies of human resilience and innovation can inform our modern strategies for addressing the challenges of the emerging Anthropocene, a time frame dominated by human modulation of surface geomorphological processes and hydroclimate.

Fate and activity of heavy metals, pesticides, PAHs and other xenobiotics depend on their interaction with humic substances present in soil, coal, freshwater and marine systems. They may be deactivated due to various interactions with humic substances, and from the other hand, xenobiotics may affect the properties of humic substances. These processes are dependent on the properties of specific fractions, including humic acids, fulvic acids and humin. Papers covering various aspects of mutual interaction between humic substances and heavy metals, pesticides and PAHs are welcome. This will provide deeper insights and understanding of the mechanisms of xenobiotics sorption on humic substances, as well as their influence on properties of humic substances occurring in terrestrial and aquatic systems.

Peatlands develop in specific hydrological settings and react sensitively to changes in climatic and hydrological boundary conditions. The hydrology of peatlands is fundamental to their function and development. Soil hydrological properties can change drastically after human interventions such as drainage, causing challenges for both model parameterisation and re-wetting measures. Pristine peatlands offer and regulate a number of ecosystem services such as biodiversity, carbon storage and nutrient retention. Hydrology is a key control for a number of these services but studies on peatland hydrology are surprisingly scarce. Furthermore, the effects of peatlands (both pristine and disturbed) on flood retention and on regional climate are much debated, but there seem to be more myths than data. As hydrological and biotic processes in peatlands are strongly coupled, estimating the eco-hydrological response of peatlands under climate change and linking it to vegetation development and greenhouse gas emissions is a demanding task for modellers.
This session aims to bring together peatland scientists to focus on improved understanding of hydrological processes operating in all types of peatlands. Peatlands being considered may be pristine or disturbed and degraded and may also include rehabilitation and re-wetting interventions. Hydrological data may have been collected for other reasons (e.g. carbon flux calculations) but the session welcomes re-examination of such hydrological data in its own right or as supporting data for other studies. All aspects of peatland hydrology are welcome to boost knowledge transfer across scales and methods; from the pore to the global scale, including laboratory, field, remote sensing and modelling studies on hydrological, hydrochemical or geophysical topics, as well as ecosystem service assessments.

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Organization of the Peatland Hydrology session:

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One more note, especially addressed to young researchers! At EGU, we would meet in person after an oral presentation or in the poster hall. Don't hesitate to e-mail people and ask for a skype call as if you were live at EGU !!! Don't allow the physical distance as a hurdle for your scientific development. Our Earth faces big challenges, no need to waste time through inefficient scientific exchange!

best wishes and enjoy EGU20,
Michel Bechtold
Ullrich Dettmann
Joseph Holden
Bjørn Kløve
Marie Larocque

Soil is the largest carbon (C) reservoir in terrestrial ecosystems with twice the amount of atmospheric C and three times the amount in terrestrial vegetation. Carbon related ecosystem services include retention of water and nutrients, promoting soil fertility and productivity and soil resistance to erosion. In addition, changes in the soil C can have strong implications for greenhouse gas emissions from soil with implications in environmental health.

Drivers controlling C pools and its dynamics are multiple (e.g. land use/vegetation cover, climate, texture and bedrock, topography, soil microbial community, soil erosion rates, soil and other environment management practices, etc. ) and some of them are mutually interacting. Also, rate of net soil C loss can be high in some environments due to both climatic constrains or management. Thus, investigation of C dynamics should be addressed with regards to the climate change and climatic extreme events to provide a better understanding of carbon stabilization processes and thus support decision making in soil management and climate adaptation strategies.

The present session highlights the importance of soil C changes, and the interaction among the mechanisms affecting C concentration and stocks in soil. Discussion about the proxies to measure and model C stocks, with special emphasis to cropping systems and natural/semi-natural areas, is encouraged. These proxies should be approached at varying the availability of soil and environment information, including, e.g., soil texture, rainfall, temperature, bulk density, land use and land management, or proximal and remote sensing properties. Studies presented in this session can aim to a wealth of aims, including soil fertility, provision of ecosystem services, and their changes, and the implication for economy, policy, and decision making.

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, and meta-analysis. These works will be evaluated at the light of the organisation of a special issue in an impacted journal

Organo-mineral associations are recognized as key factors in stabilizing organic matter within microaggregates and even larger structural units in soil. A better understanding of the mechanisms behind the formation and stabilization are essential to predict or manage soil
structure, fertility and organic matter dynamics. Recent studies point to the highly dynamic nature
of the structural units of soil, while the major interaction mechanisms, e.g. adsorption and
and coprecipitation, are strongly dependent on the environmental conditions. Microaggregates including the OM-associations may form, alter, and break up depending on the local milieu (i.e., the presence of minerals, redox conditions, pH, water content, type of organic molecules, biotic drivers, etc.), under natural and management-induced variations in soil. With the growing experimental and observational evidence of the existence and build-up of these sub-micrometer soil compounds, in turn the number of modeling approaches increase that aim for an advanced mechanistic understanding of the formation and stabilization processes, the resulting 3d-structures, and their role in the functioning of soil. With this session, we respond to the growing awareness and intensive debate of the importance of the sub-micrometer-architecture for the dynamics and functioning of soils. Presentations will focus on studies that investigate organo-mineral interactions up to the size of microaggregates in soil and sediments, including their time dependence, conceptual, analogic or numerical modeling, the spatial explicit characterization of organo-mineral associations down to the nanoscale through high-resolution imaging microscopies and spectroscopies, the impact of plant C input, the role of the soil fauna and microorganisms, as well as their potential to increase C storage in any types of ecosystem.

Note: This session is a merger of SSS5.6 "Organo-mineral association dynamics in soil" and SSS5.10 "Microaggregates in Soil"

The Amazon forest is the world’s largest intact forest landscape. Due to its large biodiversity, carbon storage capacity, and role in the hydrological cycle, it is an extraordinary interdisciplinary natural laboratory of global significance. In the Amazon rain forest biome, it is possible to study atmospheric composition and processes, biogeochemical cycling and energy fluxes at the geo-, bio-, atmosphere interface under near-pristine conditions for a part of the year, and under anthropogenic disturbance of varying intensity the rest of the year. Understanding its current functioning at process up to biome level in its pristine and degraded state is elemental for predicting its response upon changing climate and land use, and the impact this will have on local up to global scale.
This session aims at bringing together scientists who investigate the functioning of the Amazon and comparable forest landscapes across spatial and temporal scales by means of remote and in-situ observational, modelling, and theoretical studies. Particularly welcome are also presentations of novel, interdisciplinary approaches and techniques that bear the potential of paving the way for a paradigm shift.

Terrestrial ecosystems across the globe are being exposed to elevated atmospheric CO2, causing increase in temperatures and more frequent and intense drought and rainfall events. These changes have strong implications for biogeochemical cycling and the functioning of terrestrial ecosystems. Understanding the mechanisms controlling the response of plants and soil biota to climate change is therefore critical to predict potential feedbacks of terrestrial ecosystems to future climate scenarios.

The aim of this session is to bridge the knowledge of different disciplines to elucidate the multi-scale mechanisms and feedbacks underpinning the biogeochemical response to climate change, with emphasis on warming, drought and drying-rewetting dynamics. This session will give a broad overview of empirical and modelling studies across different scales, considering how climate change affects terrestrial biogeochemistry and the interactions between soil, microorganisms, plants and fauna. Attention will be given to the resistance or adaptation mechanisms of plants and soil biota during single or repeated environmental disturbances, as well as to the resilience and the associated temporal recovery dynamics after a disturbance. We will bring together researchers from different environments and create a discussion platform to review the current state-of-the-art, identify knowledge gaps, share ideas, and tackle new challenges in the field.

The changes in mineral and organo-mineral assemblages during pedogenesis are affected by chemical weathering and transformation of primary minerals over a wide range of time scales. The subsequent formation and transformation of secondary minerals are tightly linked to hydrological conditions and biological processes. Changes in mineral types, organo-mineral organisation and reactivities constrain the biogeochemical cycles of major elements (e.g., silicon, carbon, nitrogen, phosphorus, and sulphur) and trace elements (e.g., iron, manganese, antimony, cadmium, molybdenum, and selenium) which are often intricately coupled and controls the release, transport, and immobilization of nutrients and toxic trace elements, especially in redox-dynamic soil environments. The distribution of elements in soil affects soil quality, biota, ecosystem health, and ultimately, Earth’s climate and life. In this session, we invite field, laboratory, and modelling studies from a molecular-level to ecosystem observations exploring:
(1) the mechanisms and rates of mineral weathering, formation, and transformation at different time scales, as well as the links to biogeochemical element cycling,
(2) the speciation, reactivity, and environmental fate of elements during soil wetting and drying, freezing and thawing, and changing water-flow regimes, and
(3) the impact of mineral weathering and redox oscillations on element turnover, climate, and biota.

Organic substances in the soil are very heterogeneous and include low and high molecular weight compounds, and may be derived from plant and microbial residues. Besides contribution to soil organic matter (SOM) formation, living microorganisms regulate C and nutrient cycles by recycling processes. Detailed analyses of SOM transformation can highlight the role of selective preservation mechanisms, for example, and how these are modified and influenced by biological, physical and chemical interactions. In order to link processes of SOM formation with the pools, the broad range of approaches is used, including an application of various isotopes 13C/14C, 15N, 18O, 33P and analysis of plant and microbial biomarkers comprising both structural and chemical aspects related to SOM turnover. The specific attention is dedicated to the low molecular weight organic substances (LMWOS), which serve as a fuel for microorganisms, regulates their activity, composition, the transition from dormant to active stages and transformation of SOM (e.g. priming effect).
Thus, this session invites contributions, especially from early-career students, to i) the fate and turnover of organic substances in soil: from uptake and utilization by microorganisms to stabilization in SOM, ii) functions of LMWOS for priming of SOM decomposition, regulation of nutrient availability and rock weathering, iii) microbial recycling of elements (C, N, and P) from fresh or aged organic material. Analytical approaches comprising structural and chemical aspects related to SOM, such as potential biomarkers, isotopes, and their combinations are highly desirable. We also encourage contributors to present and discuss analytical challenges that remain due to both environmental and analytical uncertainty.

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