masting

Masting, also called mast seeding, is the reproductive strategy in which populations of plants produce large numbers of seeds in some years and relatively few in others. This pattern is especially common in temperate trees and shrubs, including oaks, beeches, maples, and some conifers. A mast year involves a synchronized, high seed output across many individuals, often followed by years with much lower production. The result is a pulse of available seeds that can influence consumer populations and forest dynamics.

Several mechanisms are proposed to explain masting. The resource budget model suggests individuals accumulate carbohydrates and nutrients over multiple years and only initiate a mast when reserves exceed a threshold. Environmental cues such as favorable weather conditions during flowering and seed development can synchronize production across individuals. The predator satiation hypothesis posits that producing many seeds in a single year reduces the likelihood that any one seed will be eaten, improving overall seed survival. In some species, synchronized flowering also enhances pollination efficiency.

Ecological consequences of masting include effects on seed survival, dispersal, and regeneration, as well as impacts on animal populations that feed on seeds. Mast events can influence forest composition and structure by altering seedling recruitment in subsequent years. Because mast timing and intensity vary among species and environments, researchers study mast as a population-level phenomenon, using metrics such as the coefficient of variation of annual seed production to characterize mastiness.

In summary, masting describes episodic, synchronized seed production with wide ecological implications for plants, animals, and communities.