Dynamics, Mechanisms, and Consequences of Mast Seeding

Mast seeding is the phenomenon in which perennial plants produce seed crops in highly variable and synchronized pulses. The irregular seed production associated with masting reverberates through food webs, influencing consumer abundance, behavior, life history strategies, and broader ecosystem processes. In this article, we review how plants achieve dramatic interannual variation in seed output, developing hypersensitivity to external weather cues to modulate annual flowering effort, and leveraging processes associated with pollination and fruit maturation, all of which interact with internal plant resource dynamics. We highlight evidence indicating that masting is more commonly driven by variation in flowering effort rather than fruit maturation. Additionally, weather cues typically synchronize reproduction more efficiently than density-dependent pollen limitation (known as pollen coupling). Emerging research is uncovering the gene networks underpinning weather sensitivity, offering new insights into how masting patterns may shift as the climate warms. Contrary to earlier predictions, masting is not exclusively found in temperate habitats; supraannual peaks in reproduction appear in tropical systems too, although the wider consequences of tropical masting remain unknown. To conclude, we discuss how this knowledge can improve conservation and management strategies, including through the use of masting forecasts, and highlight productive research approaches and potential pitfalls for studying masting.