Cork oak (Quercus suber)

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Species: Quercus suber

Family: Fagaceae

Common names: Cork oak; Alcornoque (Spanish); Suro, alzina surera (Catalan); Chêne-liège (French)

Brief description: evergreen sclerophyllous tree. Short-lived foliage (ca. 1 year). It has a very tick corky bark that if it is not debarked (most trees are debarked for cork production), it may attain more that 20 cm (example). It produce both annual and biennial acorns (Pons & Pausas 2012).

Distribution: Western Mediterranean. Portugal, Spain, France (south), Italy, Morocco, Algeria, Tunisia

Habitat: Growth on non-carbonated soils such as acidic soils on granite, schist, or sandy substrates, but does sometimes occur in limestone-derived soils, or in neutral soils overlying dolomitic bedrocks. Most stands are located in areas below 800 m altitude (low winter temperatures appears to set the geographical distribution limits, both in altitude and in continentality) and in areas with annual precipitation above 600 mm. Form pure forests, other times are mixed with pines (P. pinea, P. pinaster), and is one of the trees in the dehesas agrosystems.

Regeneration: Good post-fire resprouter from stem buds (protected by the thick and insulating bark, the cork; Pausas 1997) and from lignotuber (Molinas & Verdaguer 1993). Cork extraction increase the tree susceptibility to fire. Acorns are dispersed by the European jay (at long distances) and by rodents (at short distances) (Pons & Pausas 2007).

Uses and overuses: The bark (cork) is extracted every 9 to 12 years (depending of the site quality). It is one of the trees often occurring in dehesa (= montado) agrosystems; in such conditions, grazing or ploughing makes the regeneration of the tree very difficulties.

Status: Many population under the dehesa system are declining because the system does not allow for regeneration (overgrazing, ploughing).