Does optimality partitioning theory fail for belowground traits? Insights from geophysical imaging of a drought‐release experiment in a Scots Pine forest

• Published in: The New phytologist 2025-01, Vol.245 (2), p.546-558
• Main Authors: Shakas, Alexis, Hediger, Roman, Gessler, Arthur, Singha, Kamini, Pasquale, Giulia, D'Odorico, Petra, Wagner, Florian M., Schaub, Marcus, Maurer, Hansruedi, Griess, Holger, Gisler, Jonas, Meusburger, Katrin
• Format: Article
• Language: English
• Subjects: Coniferous forests; drone remote sensing; Drought; Droughts; Ecological effects; Electrical resistivity; Environmental changes; Forests; irrigation; Irrigation water; Moisture content; Photochemical Reflectance Index; Pine; Pine trees; Pinus sylvestris; Pinus sylvestris - physiology; Plant growth; Plant Roots - physiology; Quantitative Trait, Heritable; Resource efficiency; root water uptake; Soil - chemistry; Soil layers; Soil resistance; Soil stresses; Soil water; Stress, Physiological; Tomography; Water; Water availability; Water content; Water uptake
• ISSN: 0028-646X; 1469-8137; 1469-8137
• DOI: 10.1111/nph.20245

Summary We investigate the impact of a 20‐yr irrigation on root water uptake (RWU) and drought stress release in a naturally dry Scots pine forest. We use a combination of electrical resistivity tomography to image RWU, drone flights to image the crown stress and sensors to monitor soil water content. Our findings suggest that increased water availability enhances root growth and resource use efficiency, potentially increasing trees' resistance to future drought conditions by enabling water uptake from deeper soil layers. This research highlights the significant role of ecological memory and legacy effects in determining tree responses to environmental changes.