Format: ORAL

Diana Mara Cruz-Tejada1, Eduardo Fernndez-Pascual2, Efisio Mattana3, Angelino Carta1

1 University of Pisa, Pisa, Italy 2 IMIB Biodiversity Research Institute (University of Oviedo – CSIC - Principality of Asturias), University of Oviedo, Mieres, Spain 3 Royal Botanic Gardens, Kew, Wakehurst, United Kingdom

The understanding of seed biology of wild plant species is fundamental to address ecological, evolutionary, and biogeographical questions, as well as to the success of seed-based conservation and restoration actions. Despite recent attempts to synthesise seed germination knowledge across major temperate biomes, most assumptions about the germination ecology of Mediterranean plants are based on individual species or local studies, missing an integrated view of germination patterns for the whole Mediterranean Basin biodiversity hotspot. Here, we performed a binomial phylogenetically informed Bayesian meta-analysis, considering c. 7000 germination tests of c. 400 species characteristic of EUNIS Mediterranean habitats (European habitat classification system) from laboratory experiments conducted across the Mediterranean Basin. We estimated the effect on germination proportions of five environmental cues, including mean incubation temperature, temperature regime, light, and dormancy-breaking treatments for typical Mediterranean plants (i.e., species that only occur in lowland habitats of the Mediterranean Basin) and generalist plants (i.e., distribution wider than the Mediterranean Basin). Overall, typical Mediterranean species exhibit a cold-cued germination response, a positive effect of scarification, and are insensitive to light and alternating temperatures, in accordance with previously described germination syndromes for the area. Generalist species are also stimulated by cool temperatures but show positive effects of alternating temperatures, light, and cold stratification. Our results suggest that specific germination responses could vary according to species macroclimatic constraints (typical vs. generalist species) and secondarily local habitat conditions. Indeed, we found consistent patterns across different habitats (forests, scrublands, and grasslands) with few exceptions, including anthropogenic habitats, in which opportunistic germination strategies were found. Finally, whilst phylogenetically-related species exhibit similar germination responses, our results also suggest a functional convergence of the seed germination patterns across Mediterranean species. Our integrative methodological approach emphasised the significance of utilising extensive datasets to formally test eco-evolutionary and biogeographical research questions.