Evolutionary ecology of masting: mechanisms, models, and climate change

The importance of masting for ecosystem processes is well established; now we need to understand its evolutionary and physiological drivers.Synchronous interannual variation in reproduction is driven by a combination of environmental variation, weather cues, and resource dynamics. These three major masting drivers, which span both proximate and ultimate factors, are not mutually exclusive and likely apply in all species, with varying importance.Masting improves plant fitness via well-documented density-dependent processes, but the costs of masting remain stubbornly understudied, preventing the integration required to fully understand masting variation across species.Improved understanding of masting drivers and links between weather variation and seed production will improve conservation outcomes, ecological forecasts, and guide management under climate change. Many perennial plants show mast seeding, characterized by synchronous and highly variable reproduction across years. We propose a general model of masting, integrating proximate factors (environmental variation, weather cues, and resource budgets) with ultimate drivers (predator satiation and pollination efficiency). This general model shows how the relationships between masting and weather shape the diverse responses of species to climate warming, ranging from no change to lower interannual variation or reproductive failure. The role of environmental prediction as a masting driver is being reassessed; future studies need to estimate prediction accuracy and the benefits acquired. Since reproduction is central to plant adaptation to climate change, understanding how masting adapts to shifting environmental conditions is now a central question. Many perennial plants show mast seeding, characterized by synchronous and highly variable reproduction across years. We propose a general model of masting, integrating proximate factors (environmental variation, weather cues, and resource budgets) with ultimate drivers (predator satiation and pollination efficiency). This general model shows how the relationships between masting and weather shape the diverse responses of species to climate warming, ranging from no change to lower interannual variation or reproductive failure. The role of environmental prediction as a masting driver is being reassessed; future studies need to estimate prediction accuracy and the benefits acquired. Since reproduction is central to plant adaptation to climate change, understanding