
Mast Science
What Is a Mast Year? Why Seed Crops Boom and Bust
A mast year is a season when a population of trees produces an unusually large seed crop, often with many individuals fruiting in synchrony across an area.
Mast production is uneven by tree, species, place, and year. We explain the patterns without pretending an acorn forecast can be read from one enthusiastic branch. Ecological mechanisms are identified as hypotheses or evidence-based patterns when the science does not support one universal cause.

A mast year is a season when a population of trees produces an unusually large seed crop, often with many individuals fruiting in synchrony across an area.