- 1Institute of Geosciences, Friedrich Schiller University Jena, Jena, Germany (ruth.magh@posteo.net)
- 2German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig, Germany
- 3Plant Ecology and Ecosystems Research, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Göttingen, Germany
- 4Department Biogeochemical Signals, Max Planck Institute for Biogeochemistry, Jena, Germany
- 5Bioclimatology, University of Göttingen, Göttingen, Germany
- 6Leibniz Centre for Agricultural and Landscape Research (ZALF), Müncheberg, Germany
- 7Institute of Geoecology, Technische Universität Braunschweig, Braunschweig, Germany
- 8Ecosystem Physiology, University of Freiburg, Freiburg, Germany
- 9Helmholtz-Centre for Environmental Research, UFZ, Leipzig, Germany
Water potential is a key driver of fluxes within natural ecosystems, governing water flow and its direction. Understanding plant hydraulics is essential in the context of climate change, as it helps evaluate the suitability of plant species for specific locations. Plant water potential, and its response to environmental changes, plays a pivotal role in this assessment.
Traditionally, the measurement of plant water potentials has been conducted destructively and intermittently, often employing time-consuming techniques e.g. using a pressure chamber. This has resulted in low temporal resolution of water potential data for individual plants. In contrast, meteorological forcing and topsoil moisture often exhibit much greater variability. This mismatch hinders our understanding of plant responses to changing environmental conditions. This study evaluated the performance of a novel microtensiometer for continuous stem water potential monitoring. Using soil matric potential data at multiple depths, meteorological variables, and the Standardised Precipitation Evapotranspiration Index (SPEI), we analysed stem water potential drivers across three German forest sites via boosted regression trees.
The microtensiometer demonstrated reliability across environmental conditions and for several deciduous tree species (i.e., Fagus sylvatica, Fraxinus excelsior, Carpinus betulus), provided the installation depth was appropriately adjusted for ring-porous species.
Boosted regression analysis revealed soil matric potential at varying soil depths as the primary influence on hourly stem water potential. Uppermost soil layers predominantly influenced stem water potential during the day, while deeper soil layers became more important towards the late evening. This research underscores the microtensiometer's potential to advance plant hydraulics research, offering a continuous, cheaper and minimal-destructive tool to monitor water potential dynamics in forest ecosystems, particularly in the context of a changing climate.
How to cite: Magh, R.-K., Paligi, S. S., Papastefanou, P., Klosterhalfen, A., Rohde, C., Dubbert, M., Beyer, M., Haberstroh, S., Werner, C., Pohl, F., and Hildebrandt, A.: Continuous Observations Highlight Depth-Dependent Soil Matric Potential as Drivers of Stem Water Potential in Temperate Forests under non-drought conditions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8878, https://doi.org/10.5194/egusphere-egu25-8878, 2025.
