H 2 (cm), height growth after two growing seasons; Topt (°C), optimal temperature for net (An) and gross (Ag) photosynthetic rate; Aopt (µmol m−2 s−1), photosynthetic rate at Topt. gs_25, stomatal conductance at a reference temperature of 25°C; Q10, rate of change in dark respiration with a 10 °C increase in temperature; Rd10 (µmol m−2 s−1), basal rate of dark respiration (at 10 °C); Nmass, needle nitrogen concentration (mg g−1); SLA, specific leaf area (cm2 g−1).