We collected acorns from selected Quercus robur and Quercus petraea mother trees growing at stations with different depths to the water table.We produced pairs of micro-cuttings from these single acorns.The obtained pairs of cuttings represented phenotypes of high similarity according to photosynthetic parameters.These pairs of cuttings were used to test the plasticity of response to contrasting water regimes.For each pair,one cutting was submitted to drought and the other was submitted to waterlogging.Drought response was recorded according to gas exchange traits(stomatal closure and water use efficiency).The response to waterlogging was recorded according to the capacity to form hypertrophied lenticels and to maintain the CO_2 assimilation rate.Intermediary phenotypes presenting both high water use efficiency and the capacity to develop hypertrophied lenticels were expected. We collected acorns from selected Quercus robur and Quercus petraea mother trees growing at stations with different depths to the water table. We produced pairs of micro-cuttings from these single acorns. The obtained pairs of cuttings represented phenotypes of high similarity according to photosynthetic parameters. These pairs of cuttings were used to test the plasticity of response to contrasting water regimes.For each pair, one cutting was submitted to drought and the other was submitted to waterlogging. Drought response was recorded according to gas exchange traits (stomatal closure and water use The response to waterlogging was recorded according to the capacity to form hypertrophied lenticels and to maintain the CO 2 assimilation rate. Intermediary phenotypes presenting both high water use efficiency and the capacity to develop hypertrophied lenticels were expected.