of Fagus sylvatica Fagus sylvatica L. from Italy and Germany ? L. from Italy and Germany ? Linking ecophysiology and genetics Linking ecophysiology and genetics COST Action E52: Evaluation of Beech Genetic Resources for Sustainable Forestry

Fagus sylvatica (Montierzi (GR), Italy) and F. sylvatica f. purpurea were grafted on F. sylvatica rootstocks. Plants were grown under controlled conditions in a climate chamber (Fig. 1). Air temperature were 22-25°C and humidity 50% during light period and 15°C and 80% at night,. In each chamber 18 36W fluorescent lamps are placed. The photosynthetic active photon flux density (PPFD) was 250 µmol m -2 s -1 in plant height. CO 2 level were ambient concentration (approx. 380-400 ppm) and 1000 ppm, respectively. A PAM modulated fluorescence system (PAM- 2000, Heinz Walz GmbH, Effeltrich, Germany) with a 6 mm diameter standard fibre optic was used for the measurements of the in vivo photosynthesis (Fig.2). Light response curves were recorded up to a light intensity of 420 µmol m -2 s -1 .