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
Nyssa sylvatica long stalk and a rich source or nectar for bees. They are often dioecious so a male and female tree in proximity is required to set seed, however, many trees are also polygamo-dioecious, which means they have both male and female flowers on the same tree. The fruit is a black-blue, ovoid stone fruit, about 10 mm long with a thin, oily, bitter-to-sour tasting flesh and very popular with small bird species. There are from one to three fruits together on a long slender stalk. They are a valuable energy food for birds, especially the American robin. "Nyssa sylvatica" forms