Cork Oak Quercus suber

A Cork Oak in the Algarve: cork can be harvested every nine years, and here the outer bark has recently been stripped from the base of the trunk.

So much cultural, economic and biological value is rarely embodied in a single species. The Cork Oak is one of 600 species in the genus Quercus (27 in Europe), which also includes the Garry Oak featured as a Special Species in A Rocha International News July 2004. The Cork Oak is distributed across the western Mediterranean (Morocco, Algeria, Portugal, Spain, France, Corsica, Sardinia, Italy) as well as some other regions of similar climate in South America, South Africa and southern Australia where it has been introduced. An evergreen tree of modest stature (30-40 ft height) and lifespan (200 years) it dominates extensive areas of the famous montados (wood pastures) of Portugal, making this one of the most forested of all Mediterranean countries. It is also the world’s biggest producer of the prized outer bark, or cork, which is sustainably harvested, processed and sold as wine stoppers, floor tiles, insulation and as many other products. Harvesting begins when a tree is about 25 years old, and follows a nine-year cycle of stripping and regrowth, attaining 15-18 cuts in a typical tree’s lifespan. From one hectare (two and a half acres) of montado, with 40-50 trees, a tonne of cork can be produced per cycle, giving the farmer handsome returns. A certain Dr Russel Smith, writing in the Geographical Review, once commented that no other land provides so permanent and secure a base for a comfortable living than a few hundred acres of Portuguese montado.

A branch with abundant lichens on the old growth.

The economic value of cork lies in its special properties: its lightness, yet impermeability to liquids and gases, its elasticity and compressibility. As a material, it also confers a huge survival advantage to the tree, protecting it from the forest fires which are so prevalent in Mediterranean climates. Near to the A Rocha centre, Cruzinha, in southern Portugal, survivors could be seen aplenty on the scarred hills of Monchique following the fires that swept through more than 70% of the area in 2003. Whereas most trees and shrubs are killed off above-ground and resprout from the base, or recolonise from seed, the Cork Oak demonstrates post-fire regrowth from its upper branches, which together with the trunk has been protected by the cork heat shield. A Rocha has been studying the biodiversity of these Cork Oak forests for many years – a diversity far greater than in the swathes of neighbouring eucalyptus, pine and acacia. The wildlife they support can be unexpected too: tracing the route of pipistrelle bats feeding around Cruzinha revealed their nearby roost site to be – a Cork Oak! The montados themselves can support 60 species of nesting birds and are favoured habitats of Egyptian Vultures Neophron percnopterus and Spanish Imperial Eagles Aquila adalberti. The canopy and open spaces promote rich herbaceous plant assemblages, across which the Iberian Lynx Lynx pardinusonce trod…

Preserving and restoring these rich ecosystems is a key conservation priority, as they are not only threatened by the modern plantations but also by rural depopulation and the loss of a whole way of life undergirded by, but also supporting, landscapes of this tree. Can anything be done? To start with, when it comes to bottle-stoppers, choose cork! Portugal’s wildlife-rich montados depend on a continuing demand for cork.

Will Simonson, Scientific Director