Droughts in the Netherlands have been exacerbated by climate change, urging better scientific understanding of the hydrological cycle. Moreover, reliable predictions and management rely on accurate water observations at the surface. To date, the Royal Netherlands Meteorological Institute (KNMI) primarily estimates evaporation based on the meteorological conditions such as precipitation and temperature. Meanwhile, the Cabauw Experimental Site for Atmospheric Research has maintained decades of in-situ evaporation observations, exploring a range of indirect in-situ methods. Nonetheless, to better understand how moisture leaves the surface, more direct methods are required. A new smart lysimeter has been deployed which measures the water inflow and outflow of a representative soil and vegetation column. We evaluate this direct method for measuring evapotranspiration and
compare the performance to other established methods, such as the eddy covariance method. Lysimeter measurements, although precise, are spatially limited, sensitive to small-scale variations, and require rigorous validation. Therefore, we present the initial results of the validation and explore the lysimeter’s potential as a reference standard for more accessible instruments that could broaden the scope of the evaporation observations network. Furthermore, by integrating supplementary in-situ measurements, our findings suggest that applying validated lysimeter data may lead to better closure of the surface energy balance. Looking towards the future, these results have the potential to advance hydrological research,
inform models, as well as environmental decision-making.
How to cite: de Bruijn, E. I. F. and Strickland, J. M. I.: Measuring Evapotranspiration at Cabauw (The Netherlands) , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21639, https://doi.org/10.5194/egusphere-egu25-21639, 2025.
Climate change poses a significant threat to global natural- and agroecosystems, affecting key soil microbial communities, such as arbuscular mycorrhizal fungi (AMF). These fungi form symbiotic relationships with most terrestrial plants, including economically important ones like fruit trees. AMF are significantly sensitive to various climatic parameters, which influence their species composition, diversity, and ecological functions. Additionally, climate change alters AMF temporal dynamics, affecting their growth, distribution, and interactions with host plants across seasons.
Despite these insights, a critical knowledge gap remains in understanding how multiple climatic parameters simultaneously affect the dynamics of AMF communities. This study aims to address this gap by investigating the response of AMF in pear orchards to the worst-case climate scenario (i.e., RCP8.5) projected for Belgium in 2040. We used a state-of-the-art Ecotron facility, to simulate both ambient (2018) and future (2040) climate conditions in a pear orchard. In total six trees have been grown in the Ecotron in each of the climatic conditions. We assessed diversity, composition, and temporal dynamics of AMF spores, revealing patterns of dormancy and activity, and providing insights into shifts of AMF community phenology induced by climate change. Our research elucidates climate-driven dynamics of AMF in agricultural systems, and provides insights into maintaining sustainable crop production and soil fertility under future climate conditions.
How to cite: Vercauteren, C., Claessens, V., and Soudzilovskaia, N.: Investigating the Effects of Future Climate Scenario on Arbuscular Mycorrhizal Fungal Spore Dynamics in a Belgian Pear Orchard Ecosystem, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7456, https://doi.org/10.5194/egusphere-egu25-7456, 2025.
Projected climatic conditions, such as more frequent and prolonged droughts, are expected to become more common in many regions of the world according to the IPCC 2023 report, particularly in the Mediterranean. These conditions can reduce plant CO2 uptake, gross primary productivity, and decomposition rates, potentially disrupting the carbon cycle. While higher soil biodiversity might mitigate these adverse drought effects by enhancing productivity and decomposition stability, the net effect on ecosystem CO2 exchange remains largely uncertain, making future carbon cycle predictions challenging.
Using a reconstructed Mediterranean understory model ecosystem, we conducted a three-year experiment in 16 lysimeters (1m³ soil volume, 1m² surface area) at the Montpellier European Ecotron (www.ecotron.cnrs.fr). We tested two levels of decomposer functional diversity (low and high) under ambient summer drought and more intense drought conditions (-30% precipitation and longer drought spells). Our results show that higher decomposer functional diversity maintained up to 25% higher gross primary productivity (GPP) during the early stages of drought. This response was partly due to better water uptake from the deeper soil layers, as indicated by volumetric water content sensors.
How to cite: Milcu, A., Barantal, S., Gritti, E. S., Laoue, J., Nahmani, J., and Hattenschwiller, S.: Higher decomposer functional diversity bolsters ecosystem gross primary productivity resistance under drought: a three-year ecotron study, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11225, https://doi.org/10.5194/egusphere-egu25-11225, 2025.
Soil solution sampling is a critical approach to understand the dynamics of water and nutrient transport in terrestrial ecosystems, however little information is available for high-elevation environments. During the summer 2024, soil solution was sampled at 10 cm depth in the Long Term Ecological Research-LTER site Istituto Mosso (2650 – 2900 m a.s.l., NW Italian Alps), using 30 soil disc lysimeters among 3 distinct vegetation communities belonging to alpine tundra ecosystem: snowbed communities, Carex curvula grasslands, and mixed conditions. This work presents new insights in the application of soil suction lysimeters at high-elevated, logistically-complex environments. By collecting and analyzing the soil solution, we aimed to contribute to the comprehension of the functioning of alpine tundra ecosystems, particularly under the pressure of climate change, focusing on the possible shift in vegetation cover from snowbed communities toward Carex curvula grasslands due to higher air/soil temperature and earlier spring snowmelt. These measurements were complemented by continuous monitoring of soil temperature and moisture, providing a comprehensive understanding of soil dynamics in these ecosystems. Special attention was paid to the transport processes of water and nutrients (namely carbon and nitrogen), which are fundamental to understand biogeochemical cycling in alpine areas. Notably, the content of Dissolved Organic Carbon (DOC) was the highest in Carex curvula grasslands, while nitrate concentrations exceeded those of ammonium across all sites. The outcomes of this study are expected to contribute to advancing methodologies in soil solution sampling and provide critical information for evaluating alpine ecosystem responses to changing climatic conditions. These findings will also help refining our understanding of water and nutrient dynamics, offering implications for both ecological research and management strategies in vulnerable high-elevation environments.
Research supported by NBFC - University of Turin/DISAFA, funded by the Italian Ministry of University and Research, PNRR, Mission 4 Component 2, “Dalla ricerca all’impresa”, Investment 1.4, Project CN00000033
How to cite: Benech, A., Pintaldi, E., Colombo, N., and Freppaz, M.: Soil solution chemistry along a land cover transect in the alpine tundra (NW Italian Alps), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8343, https://doi.org/10.5194/egusphere-egu25-8343, 2025.
The dynamic changes of soil water and salt are crucial for crop growth and agricultural productivity. Understanding soil water and salt movement mechanisms, influenced by natural and human factors like climate change, groundwater, and brackish water irrigation, remains challenging. This study focused on the Yellow River Irrigation District, a critical grain-producing area with limited freshwater resources and saline soils. Using Yucheng Station as a case study, field experiments (2004–2020) and model simulations (2023–2053) were conducted to investigate the dynamics and influencing factors of soil water and salt under winter wheat-summer maize rotation.
Field experiments revealed that crop yields decreased with groundwater depth, significantly impacting soil water and salt dynamics. HYDRUS-1D simulations, calibrated with monitoring data (2020–2023), effectively captured these dynamics, achieving high accuracy in soil moisture and salt concentration predictions. Climate change scenarios showed soil water and salt fluctuations aligned with crop growth cycles, with rainfall intensity and crop evapotranspiration being key factors. Higher rainfall in SSP585 scenarios enhanced salt leaching compared to SSP245, while salt accumulation in the cultivation layer was prominent during dry years.
Groundwater depth significantly influenced farmland-water interactions. At shallower depths (2 m), groundwater contributed substantially to crop water use but posed risks of soil salt stress. Conversely, deeper depths (4 m) reduced these contributions, highlighting the balance needed for optimal groundwater management. Long-term brackish water irrigation showed increasing soil salt trends, with salt migration influenced by rainfall and groundwater depth. To mitigate risks and enhance brackish water use, irrigation with ≤3 g/L salt concentration and groundwater depth control at 3 m is recommended for sustainable soil water and salt management, ensuring crop productivity and food security under future climate conditions.
How to cite: Li, F., Qiao, Y., and Li, Z.: Dynamics of Soil Water and Salt in Saline Farmlands: Implications for Brackish Water Irrigation and Climate Resilience, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16521, https://doi.org/10.5194/egusphere-egu25-16521, 2025.
Controlled Environment Facilities (CEFs) – including phytotron, ecotron, and lysimeter systems – are essential tools in experimental plant research. Studies conducted in CEFs have substantially advanced our understanding of ecological, physiological, and molecular responses to environmental factors, and have played an important role in the development and parameterization of mechanistic models.
Until recently, climate change research in controlled environments primarily focused on the static manipulation of a single (or few) parameters, notably temperature. However, modern CEFs now enable the highly precise, simultaneous control of multiple environmental variables, such as temperature, VPD, light, soil temperature, and soil moisture, as well as the accurate manipulation of atmospheric gases (e.g., CO₂ and ozone).
The ability to maintain these factors at high temporal resolution effectively turns CEFs into “time machines,” allowing researchers to investigate plant and model-ecosystem responses under realistic climate change scenarios. Although the technical implementation of complex climate series has become more feasible, the core challenge lies in generating climate series that capture potential future conditions while avoiding oversimplification and meeting the scientific requirements for standardization and reproducibility.
In this contribution, we present examples from various experiments conducted at the TUM Model EcoSystem Analyser (TUMmesa). These range from incremental manipulation of individual environmental variables, through the replication of historically recorded climate series, to the dynamic downscaling of global climate models driven by representative concentration pathway (RCP) scenarios.
These recent advancements highlight the potential of modern CEFs to deepen our understanding of plant-environment interactions and support robust investigations of climate change impacts on terrestrial ecosystems.
How to cite: Jákli, B., Meier, R., and Baumgarten, M.: The Ecotron Time Machine – Simulating Climate Change in Controlled Environment Facilities, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18588, https://doi.org/10.5194/egusphere-egu25-18588, 2025.
For studying the effects of future climate conditions on plant physiological, biogeochemical, hydrological and atmospheric processes in agroecosystems, we developed a large-scale research infrastructure, called AgraSim. AgraSim is an experimental simulator consisting of six mesocosms, each of them consisting of an integrated climate chamber, plant chamber and lysimeter system. The system makes it possible to simulate the environmental conditions in the mesocosms in a fully controlled manner under different weather and climate conditions ranging from tropical to boreal climate. Moreover, it provides a unique way of imposing future climate conditions which presently cannot be implemented under real-world conditions. It allows monitoring and controlling states and fluxes of a broad range of processes in the soil-plant-atmosphere system. This information can then be used to give input to process models, to improve process descriptions and to serve as a platform for the development of a digital twin of the soil-plant-atmosphere system. In detail, each mesocosm consists of a high-precision lysimeter (weighable, control of temperature and lower boundary) with a monolithic soil core (1 m2 surface area and 1.5 m depth) and a transparent, fully controllable plant chamber (7 m3 volume) with an LED light source very similar to the natural solar spectrum with a maximum intensity of 2,500 μmol of photosynthetically active photons per square meter and second. With an in-house developed, fully automated process control system, defined climatic and weather conditions as well as air compositions can be set and varied on the basis of a predefined weather data profile. The inner surfaces of the plant chambers have the purest and most inert properties possible, with the aim of minimizing interactions between the ambient air of the plants and the chamber wall. Strong LED-based plant lighting provides light conditions similar to daylight, which prevents too large heat input into the chamber. A new concept was developed and implemented to dissipate this heat by avoiding condensation at all times, as condensation dissolves gas molecules from the air in the condensate, changing the isotope composition and thus impeding the atmospheric measurements. The process technology includes the precise control of the supply air volume flow, pressure, humidity, carbon dioxide content, air temperature, light intensity within the plant chamber, soil temperature and irrigation.
How to cite: Neumann, J., Brüggemann, N., Chaumet, P., Hermes, N., Huwer, J., Kirchner, P., Lesmeister, W., Mertens, W. A., Pütz, T., Wolters, J., Vereecken, H., and Natour, G.: Development of the "Agricultural Simulator" AgraSim for comprehensive experimental simulation and analysis of environmental impacts on processes in the soil-plant-atmosphere system, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8359, https://doi.org/10.5194/egusphere-egu25-8359, 2025.
Lysimeter systems play a crucial role in understanding the complex interactions within the soil-plant-atmosphere continuum. In the context of climate change, where precise insights into water and nutrient fluxes, energy exchange, and greenhouse gas dynamics are essential, lysimeters equipped with advanced hydraulic and thermal controls are increasingly indispensable. A key innovation in this field is the integration of suction-controlled hydraulic boundary conditions and active temperature regulation, which significantly enhances the capability of lysimeters to mimic natural processes while maintaining experimental control. These functionalities are particularly critical in ecotron experimental platforms, where controlled yet realistic environmental conditions are required for high-resolution and high-quality observations.
Our research focuses on the optimization of lysimeter design and functionality using advanced computational tools. Specifically, we developed a 2D- and a comprehensive 3D-modeling approaches to investigate and refine the technical design of lysimeter systems equipped with underpressure-controlled hydraulic boundary conditions and temperature regulation mechanisms. Two simulation models, HYDRUS and FEFLOW, were systematically tested and compared for their suitability in simulating these complex systems.
We present the results of scenario analyses conducted to evaluate and optimize critical design parameters, including (1) the number and spatial arrangement of suction cups required to achieve precise suction-controlled hydraulic boundary conditions, (2) the number, positioning, and dimensions of heat exchanger pipes for effective temperature regulation and (3) the influence of insulation thickness at the bottom of the lysimeter on thermal efficiency and system stability. Our findings also demonstrate the strengths and limitations of both HYDRUS and FEFLOW in capturing the dynamics of water and energy transport in lysimeters. Our work not only contributes to the technical advancement of lysimeter and ecotron platforms but also supports their broader application in ecosystem research. By integrating robust design methodologies with cutting-edge simulation tools, we provide a framework for enhancing the reliability and functionality of these experimental systems.
In conclusion, this study highlights the potential of modeling and scenario-based optimization in improving the design and operational efficiency of lysimeters with advanced hydraulic and thermal controls. The insights gained from our research are expected to support future applications of lysimeter and ecotron systems in addressing critical questions related to climate change impacts on terrestrial ecosystems.
How to cite: Vrzel, J., Mursaikova, M., Kupfersberger, H., and Klammler, G.: Advancing Design and Functionality of Lysimeter/Ecotron Systems through Modeling , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21644, https://doi.org/10.5194/egusphere-egu25-21644, 2025.
The need for continuous local and long-term observations in the vadose zone has been growing for many years, as they are essential for improving our understanding of the processes occurring in the vadose zone of the soil and enhancing seasonal forecasts from numerical models.
Lysimeters and Ecotrons are the main tools to directly access water and nutrient transport over long periods of time. In France, with the impulsion of the ONEWATER project, a French lysimeter network is in development since April 2024, taking benefice of the existing structure.
A workshop was organised to identify all the sites in France and to collect expectations. We considered about the major scientific questions that could be supported by such a network, and identifying the measurement systems and instruments that are compatible with our ambitions, as well as considering the management and diffusion of the data.
In 2024, 32 lysimeter sites have been identified in France, with a total of 650 lysimeters. These sites are very heterogeneous : i) different type and size of devices : (columns, boxes, plates, mini-lysimeters, porous cells, Ecotrons, etc.); ii) different filling methods (undisturbed or reconstituted), iii) different measurements (probes, frequency…), iv) different atmospheric condition (natural or controlled)… Despite each site is unique and has specific scientific objectives, they all measure drainage.
The site managers expect this network will help sharing experience in terms of device management, data valorisation and probe development, and to enable the data collected in the sites to be more used.
A main issue with this heterogeneous network is to be able to compare and interprete each site. To do so several methods will be used, from in situ temporary experiment to numerical simulations. Additional, the individual sites would benefit from some upgrade, with the use of similar low-cost probes and effort will be done to share and valorize the lysimetric data.
How to cite: Sobaga, A., Faure-Catteloin, P., Abiven, S., Habets, F., Enjelvin, N., and lysimetric network community, F.: The First year of the French lysimetric network, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6050, https://doi.org/10.5194/egusphere-egu25-6050, 2025.
Posters virtual: Thu, 1 May, 14:00–15:45 | vPoster spot A
EGU25-6894 | Posters virtual | VPS10
Water/nitrate fluxes and tranport in deep vadose zone of typical irrigated cropland in North China PlainThu, 01 May, 14:00–15:45 (CEST) | vPA.5
North China Plain is one of the agricultural region in the world with severe water shortage. Flood irrigation is still the most popular irrigation method in NCP, and have caused very low water use efficiency. Groundwater depletion becomes the most concerned issue for sustainable development. To determine the water & nitrate fluxes is important for better water resouces management. We built up a 48-m in depth of cassion and a 36 lysimeter group for this purpose to study the water budget and water/nitrate movement in the deep vadose zone. In this study, we will present the observation facts using these two facilities to reveal the differences between water transport velocity and celerity in the deep vadose zone of nearly 50 meters. This is the first time to observe the variations or responses of soil potential, moisture, temperature, and electricity conductivity to water inputs from land surface, such as extreme rainfall, directly in the deep vadose zone of 48 meters. We will also present the fresh observation results from the 36 lysimeters about ET and drainage fluxes of different cropping patterns, with different watering and fertilizing treatments. The latter experiment could provide useful information for improving the water/nutrients management for different cropping systems in NCP, and will be beneficial to sustainable groundwater management at the aspects of quantity and quality. The results of the observatoins using these new facilities is presented at international conference at the first time. We hope it could be interested by the colleagues worldwide.
How to cite: Shen, Y., Zhang, Y., Min, L., Wu, L., Li, H., and Li, H.: Water/nitrate fluxes and tranport in deep vadose zone of typical irrigated cropland in North China Plain, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6894, https://doi.org/10.5194/egusphere-egu25-6894, 2025.
