Domingo Sancho-Knapik; Nerea Urcola-Lázaro; David Alonso‑Forn; Rubén Martín‑Sánchez; José Javier Peguero‑Pina; Juan Pedro Ferrio; Eustaquio Gil‑Pelegrín
Research Square, Posted Date: February 19th, 2026
https://doi.org/10.21203/rs.3.rs-8639643/v1
0 citations · 0 en 2025–2026
Les titres, résumés et légendes des publications sont présentés en anglais.
Abstract
Context:
Young, expanding leaves are nutrient-rich and mechanically weak, making them highly attractive to herbivores. How defense timing and allocation differ during development between co-occurring evergreen and deciduous species remains unclear.
Aims:
We tested whether evergreen oaks invest more in direct defenses during leaf development than deciduous oaks, and whether each habit prioritizes distinct defensive traits across stages.
Methods:
In a Mediterranean common garden, we monitored co-occurring evergreen Quercus rotundifolia and deciduous Q. faginea from budburst to leaf maturity, measuring growth and defense traits. Seasonal trajectories and toughness–tannin relationships were analyzed, and patterns validated with three additional evergreen and three deciduous congeners.
Results:
Leaf area reached its maximum before LMA, creating a juvenile phase with low fibre content and toughness. The evergreen oak increased condensed tannins concentration early, then work of fracture; the deciduous oak grew faster initially, then reinforced mechanically and delayed tannins. Across stages, the evergreen kept higher work of fracture and condensed tannins, while the deciduous prioritized early growth; defense trade-off patterns were habit-specific and consistent across species.
Conclusion:
Leaf-habit–specific defense schedules shape protection: evergreens front-load chemical defenses before structural hardening, while deciduous oaks prioritize tolerance and earlier mechanical reinforcement, patterns with potential implications for herbivore pressure and associational dynamics in
mixed stands.
Keywords:
Condensed tannins, defense trade‑offs, leaf ontogeny, relative growth rate, work of fracture.
Utilisation des équipements
L’étude suit le développement foliaire de chênes persistants et caducifoliés, en évaluant des traits de défense comprenant la ténacité et le travail de rupture. Le résumé disponible ne précise ni l’équipement d’essai mécanique ni la méthode de mesure du travail de rupture. Le rôle du Mach-1 Mechanical Tester, notamment dans une configuration de coupe ou de perforation, ne peut pas être confirmé.
Matériaux (1)
Matériau