Holm oak fecundity does not acclimate to a drier world

Climate change might impact tree fecundity by altering the relative influences of meteorological and physiological drivers, modifying resource investment in reproduction. Using a 13-yr monitoring Quercus ilex reproduction rainfall exclusion experiment, we analysed interactive effects long-term increased aridity other environmental drivers on inter-annual variation (male flower biomass, number initiated mature fruits). Summer–autumn water stress was main driver fruit abortion during growth. Rainfall treatment strongly reduced fruits, even masting years, did not increase tolerance to severe drought. Conversely, contribution variability production were modified exclusion. Rather than inducing an acclimation limitation, impacted it negatively through both lower initiation due changes allocation, more limitations Long-term affected beyond what is expected from current response drought variations, suggesting that natural regeneration holm oak forest could be jeopardised future.