Project Details
Projekt
ZP Central project – Central research platforms and modelling approaches
Applicants
Professor Dr. Mutez Ali Ahmed; Professor Dr. Bernhard Schuldt; Professor Dr. Jan Vanderborght; Professorin Dr. Christiane Werner
Subject Area
Soil Sciences
Term
since 2026
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 538902328
A comprehensive mechanistic understanding of plant water use regulation under conditions of atmospheric and soil drying is urgently needed in the context of global climate change and the increasing frequency of drought events that threaten food security and contribute to widespread tree mortality. This can only be achieved by bridging process knowledge across scales and leveraging multidisciplinary approaches through carefully coordinated experiments that synergistically explore the underlying mechanisms and key drivers. Our central hypothesis is that the conductances of soil, rhizosphere, root, xylem and stomata are coordinated on short (daily) and long (seasonal) time scales to maintain a linear relationship between transpiration rate and leaf water potential. This coordination would enable plants to optimize growth while minimizing the risk of hydraulic failure. To evaluate cross-scale coordination, we will conduct a series of four joint laboratory and field experiments that integrate the expertise of soil physicists, molecular biologists, plant physiologists, eco-hydrologists, and large-scale modelers. In (semi-) controlled experiments, we will identify the key hydraulic limits to the transpiration rate and investigate the mechanisms governing stomatal regulation and belowground adaptations to varying soil conditions. To assess the general applicability of our hypotheses under natural conditions, field measurements will be carried out on both herbaceous and woody plant species. To ensure comparability across experiments, the same varieties of two herbaceous and two tree species will be used throughout, and all experiments will be conducted using consistent soil textures (sand and loam). In the laboratory, we will grow two genotypes of two herbaceous species each - maize and sunflower - that differ in their degree of how tightly they regulate plant water status (potential) under water stress (i.e., degree of isohydricity). These will be cultivated in medium-sized lysimeters under controlled conditions in Central Experiment 1 (CE1). The same species and soil textures will be used in an analogous setup in large outdoor lysimeters for Central Experiment 3 (CE3). In parallel, two tree species - lime and beech - representing varying degrees of isohydric behavior will be grown in large mesocosms under controlled conditions within a hangar facility for Central Experiment 2 (CE2). This setup will be mirrored in mature trees growing under natural field conditions for Central Experiment 4 (CE4), again using the same species and soil textures. The generated data will be synthesized in a conceptual framework for mechanistic modelling. The Central Project presented here will provide the necessary infrastructure, coordinate and support the experiments, integrate knowledge across disciplines, and offer a suite of modeling tools to ensure consistency across scales.
DFG Programme
Research Units
