ECOPHYSIOLOGICAL STUDIES OF MEDITERRANEAN PLANT-SPECIES AT THE CASTELPORZIANO ESTATE

The aim of this work was to characterize the eco-physiological perform ance of the main plant species of the Castelporziano site by single le af investigations. We measured the leaf gas exchange of Quercus ilex L ., Pinus pinea L., Pistacia lentiscus L. and Asphodelus microcarpus I, . for several days. Additionally, the xylem water potential of Quercus ilex, Pinus pinea and Pistacia lentiscus was recorded in order to obt ain more physiological background information for the discussion of th e trace gas emissions. This study indicates significantly different ph ysiological responses to the different environmental conditions. In pa rticular, summer conditions (high values of light, air temperature and low xylem water potentials) caused the depression of photosynthesis i n Quercus ilex and Pinus pinea but did not affect photosynthesis of Pi stacia lentiscus and Asphodelus microcarpus. This should be taken into account when discussing VOC emission rates and fluxes. (C) 1997 Elsev ier Science Ltd.