The iberian Dehesa (“Montado” in Portugal) is a unique agrosilvopastoral system where economic and social activity is generated in a perfect balance with the environment where they develop.
It is the product of human action on the Mediterranean forest areas, where usually are not appropriate other agricultural activities. The result is a combination of a grazing productive stratum and a dispersed trees stratum.
Its present condition is the result of the combined action of cultural, ecological, economic, geographic, historical, landscape, and social factors.
The main protagonist of this system is the woodland, being mainly of the genus Quercus spp, holm (Quercus ilex) and cork (Quercus suber), which acorns are a source of food for livestock and wildlife in the pasture during late fall and winter. These pasture lands are characterized by low production in winter months and no production at all during the summer months. 
The origin of the Spanish dehesa dates back at least to the Middle Ages, and possibly over 1000 years ago. The denomination of “dehesa” is derived from “defensa”, and “defessar” was defending an area of common use of their pastures, reserving certain cattle.
This agroforestry system occupies more than 3×106 hectares in the south-west Iberian peninsula. The mean tree density is around 30–50 trees ha–1, varying from isolated trees to complete tree cover (over 100 trees/ha). Several tree species are present at the dehesa systems but perennifolius Quercus ilex L. (holm oak) and Quercus suber L. (cork oak) are the dominant tree species.
The dehesa is commonly used for extensive livestock rearing, with the animals feeding on leaves, acorns and grass; cereal fodder is also grown in long rotations; and cork, firewood, charcoal, game, honey, and diverse other goods are also produced.