Seasonal courses of chlorophyll a fluorescence, gas exchange parameters and water status,
joined to environmental variables, were measured in four age classes of stone pine (Pinus
pinea L.) natural regeneration under a natural light gradient in a stone pine regular stand
throughout 2007 and 2008. One-year old seedlings were worse adapted to the extreme
drought conditions recorded in summer (especially in 2008), showing lower predawn and
midday Fv/Fm values, slightly lower photosynthetic rates at midday, lower PSII values …

Seasonal courses of chlorophyll a fluorescence, gas exchange parameters and water status,
joined to environmental variables, were measured in four age classes of stone pine (Pinus
pinea L.) natural regeneration, selected within a natural light gradient in order to cover the
whole range of incident light detected within a stone pine regular stand throughout 2007 and
2008. Selection of light conditions was based a priori on the distance of seedlings to the
parent trees, expressed by crown radius distances. One-year old seedlings were worse …