Mast (botany) some domestic animals consume. Mast is found in two forms. Mast is generated in large quantities during mast seeding events (or masting, mast events). Mast seeding is a population-level phenomenon that is hypothesized to be driven by economies of scale, weather, and resources. These pulses of resources drive ecosystem-level functions and dynamics. Tree species such as oak, hickory, and beech produce a hard mast—acorns, hickory nuts, and beechnuts. It has been traditional to turn pigs loose into forests to fatten on this form of mast. Other tree and shrub species produce a soft mast, such as raspberries, blueberries, and greenbriar.
English Lowlands beech forests its tannins had been leached out by soaking. Beechmast has also traditionally been fed to pigs. However, by 4000 BC, as Oliver Rackham has indicated, the dominant tree species was not the beech, but the small-leaved lime, also known as the pry tree. The wildwood was made up of a patchwork of lime-wood areas and hazel-wood areas, interspersed with oak and elm and other species. The pry seems to have become less abundant now because the climate has turned against it, making it difficult for it to grow from seed. Nevertheless, some remnants of ancient lime-wood still remain in south