Trade‑offs and timing of leaf defenses during development in co‑occurring evergreen and deciduous Quercus

The dataset includes measurements of leaf area, leaf mass per area (LMA), leaf thickness, leaf density, dry mass, cellulose, hemicellulose and lignin + cutin content, work of fracture, and condensed tannin concentration. This dataset has been used in the following study currently under review in Annals of Forest Science: - Title: Trade‑offs and timing of leaf defenses during development in co‑occurring evergreen and deciduous Quercus - Authors: Domingo Sancho‑Knapik, Nerea Urcola-Lázaro, David Alonso‑Forn, Rubén Martín‑Sánchez, José Javier Peguero‑Pina, Juan Pedro Ferrio and Eustaquio Gil‑Pelegrín - Key message: Evergreen and deciduous oaks resolve the early ontogenetic “vulnerability window” with contrasting defense schedules: evergreens front‑load chemical deterrence (condensed tannins) and complete mechanical reinforcement later, whereas deciduous oaks prioritize rapid growth and earlier mechanical strengthening, delaying chemical investment.