Climate change and plant regeneration from seeds in Mediterranean regions of the Northern Hemisphere

Abstract

Mediterranean regions are biodiversity hotspots whose landscapes are characterized by evergreen sclerophyllous vegetation, mild-wet winters, and hot-dry summers. In the Northern Hemisphere, they occur in the Mediterranean Basin and California regions. In these areas, whose habitats are heavily shaped by centuries of anthropic activities, the main effects of climate change include a decrease in precipitation and change in its regime, a pronounced warming, an increase in frequency of extreme temperature events, and altered and intensified fire regimes. Climate change poses a double challenge to the regeneration from seeds of Mediterranean plants. Warmer winters mainly affect the seed germination phase by limiting “typical” Mediterranean cold-cued germination in autumn/winter and reducing overwinter dormancy release for those species whose seeds germinate in spring. Harsher summers are detrimental for the establishment phase, compromising seedling survival. However, evidence of phenotypic plasticity in some Mediterranean plants suggests potential adaptation to a changing climate in the short- to medium-term for species of these regions.