ForestFuture · Climate change impacts on trees reproduction and forecasts of forest recruitment change

The capacity of future forests to support biodiversity and deliver ecosystem services will depend on reproductive capacities that keep pace with 21st century climate change. The European continent is warming and drying out fast, and similar changes are happening word wide. The decade-scale trends in biodiversity will be governed by tree fecundity?the capacity of trees to produce seed and to disperse it to the habitats where populations can survive in the future. From the boreal to the tropical forests, including in majority of European tree species, reproduction happens through synchronized, quasi-periodic, non-stationary variation in fruit production, termed masting or mast seeding. Despite the crucial role of mast seeding in plant regeneration and wider ecological processes, our understanding of this process is rudimentary. Poor understanding of the mechanisms that govern it are challenges for anticipating alternations in forest reproduction and function. Reliable predictive models are consequently not available, and the unpredictable recruitment of trees has become a key obstacle to understanding forest change. Recruitment, including reproduction and dispersal, is the most undeveloped demographic process in Earth system models. This work will transform our understanding of mechanisms governing trees reproduction and deliver tools for predicting forest reproduction trajectories under climate change. The main outcomes will be the first experimental description of how masting emerge at proximal level, and how this is conserved among species. This will be also the first explicit test of how variation in masting patterns matters for forest regeneration trajectories. Together with analysis of global reproductive patterns, our work will deliver a step-change in identifying species and regions of special conservation care.