We estimated water-use efficiency and potential photosyn- thetic assimilation of Holm oak （Quercus ilex L.） on slopes of NW and SW aspects in a replicated field test examining the effects of intensifying drought in ...We estimated water-use efficiency and potential photosyn- thetic assimilation of Holm oak （Quercus ilex L.） on slopes of NW and SW aspects in a replicated field test examining the effects of intensifying drought in two Mediterranean coppice forests. We used standard tech- niques for quantifying gas exchange and carbon isotopes in leaves and analyzed total chlorophyll, carotenoids and nitrogen in leaves collected from Mediterranean forests managed under the coppice system. We pos- tulated that responses to drought of coppiced trees would lead to differ- ential responses in physiological traits and that these traits could be used by foresters to adapt to predicted warming and drying in the Mediterra- nean area. We observed physiological responses of the eoppiced trees that suggested acclimation in photosynthetic potential and water-use effi- ciency： （1） a significant reduction in stomatal conductance （p〈0.01） wasrecorded as the drought increased at the SW site; （2） foliar 813C increased as drought increased at the SW site （p〈0.01）; （3） variations in levels of carotenoids and foliar nitrogen, and differences in foliar morphology were recorded, and were tentatively attributed to variation in photosyn- thetic assimilation between sites. These findings increase knowledge of the capacity for acclimation of managed forests in the Mediterranean region of Europe.展开更多
基金supported by the Italian Ministry for Agricultural and Forest Policy,under the programme Ri.Selv.Italia(Research unit 3.2.1,DIBAF,University of Viterbo)
文摘We estimated water-use efficiency and potential photosyn- thetic assimilation of Holm oak （Quercus ilex L.） on slopes of NW and SW aspects in a replicated field test examining the effects of intensifying drought in two Mediterranean coppice forests. We used standard tech- niques for quantifying gas exchange and carbon isotopes in leaves and analyzed total chlorophyll, carotenoids and nitrogen in leaves collected from Mediterranean forests managed under the coppice system. We pos- tulated that responses to drought of coppiced trees would lead to differ- ential responses in physiological traits and that these traits could be used by foresters to adapt to predicted warming and drying in the Mediterra- nean area. We observed physiological responses of the eoppiced trees that suggested acclimation in photosynthetic potential and water-use effi- ciency： （1） a significant reduction in stomatal conductance （p〈0.01） wasrecorded as the drought increased at the SW site; （2） foliar 813C increased as drought increased at the SW site （p〈0.01）; （3） variations in levels of carotenoids and foliar nitrogen, and differences in foliar morphology were recorded, and were tentatively attributed to variation in photosyn- thetic assimilation between sites. These findings increase knowledge of the capacity for acclimation of managed forests in the Mediterranean region of Europe.
