Work

Cascading effects of soil water content on leaf chemistry and damage: implications for plant susceptibility to pests and pathogens in a drier world

Year: 2026

Type: article

Abstract: Climate change is causing major alterations in precipitation regimes and soil water availability, with far-reaching effects on plant traits. Changes in plant chemistry under drought scenarios are particularly relevant, as they can modulate plant interactions with antagonistic organisms. However, how such changes in plant chemistry affect plant susceptibility to biotic damage remains poorly understood. Here we integrated results from a systematic literature review and a field study in Mediterranean mixed forests to advance our understanding of the cascading effects of reduced soil water content on leaf reserves, defences and damage caused by herbivores and pathogens. The literature review revealed that studies linking soil water content with leaf chemistry and damage remain scarce and reported a variety of direct and indirect relationships between the three components. Nevertheless, most studies found higher leaf damage under drier conditions. Results from our field study also supported that leaf damage increased with decreasing soil water content, a relationship largely mediated by changes in leaf phenolic compounds. In Mediterranean forests, phenolics play a major role in protection against desiccation and UV radiation due to their antioxidant properties, yet certain phenolic compounds can also benefit antagonists. Overall, our findings suggest that leaf damage can increase in a drier climate, forcing tree species to face fundamental trade-offs when protecting themselves from the combined stress imposed by abiotic (drought) and biotic (pests and pathogens) components of global change.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2026.1914073