Mast seeding under increasing drought: results from a long-term data set and from a rainfall exclusion experiment.

摘要: Mast seeding, the synchronous, highly variable seed production among years, is very common in tree species, but there no consensus about its main causes and environmental factors affecting it. In this study, we first analyze a long-term data set on reproductive vegetative growth of Quercus ilex mediterranean woodland order to identify drivers interannual variation flower contrast impact climate vs. adaptive as masting. Second, conducted an experiment rainfall exclusion evaluate effects increasing drought (simulating predictions global change models) both processes. The annual crop was always affected by related precipitation pattern, these abiotic disrupting fruiting process at different periods time. Seed strongly dependent upon water availability for plant initial (spring) advanced (summer) stages acorn maturation cycle, whereas final step development negatively frequency torrential-rain events. We also found clear evidence that masting study species not only regulated selective endogenous rhythms, mainly physiological response environment. Our results from corroborated conclusions obtained 26-year record demonstrated high determined success rather than flowering effort. Under scenario, it could be expected drier conditions predicted models reinforce negative summer production, leading consequences recruitment forest dynamics.