Mast (botany) Mast seeding is defined as the highly variable production of fruit by a population. These intermittent pulses of food resources drive ecosystem-level functions and forest dynamics. The difference between a mast seeding year and a non-mast seeding year can be thousands of acorns, hickory nuts, beech nuts, etc. Mast seeding dominantly occurs in wind-pollinated tree species, but has also been observed in grasses and Dipterocarps. Masting, in the strict sense of the term, occurs only in monocarpic (or semelparous) species, whose members reproduce only once during their lifetime, then die. Hypothesis for the evolution of mast seeding can broadly be
Forests of the Iberian Peninsula blackberry bushes, blackthorn, hawthorn and other more or less thorny shrubs; this role can also be filled by smaller thorny plants, "los piornales", and clumps of broom. The major forests in this area are beech, oak, birch, and fir. Beech forests ("Fagus sylvatica") are found in the mountain layer of the Iberian Eurosiberian region from 800 to 1500 metres up. The soil is cool, as often chalky as siliceous (rich in silica), and nearly always acidified by rain. The layer is characterised by the beech tree. The beech tree projects a deep shadow, and so its dense foliage usually excludes