A Sustainable Industry
Today, the center of the world’s cork oak forest is concentrated on Europe’s Iberian Peninsula and the adjacent Mediterranean basin, where soil, temperature, rainfall and wind conditions are ideal. European forests account for two-thirds of cork oak production, while North Africa produces the remaining one-third. The total land surface occupied by the cork oak forests is 2.2 million hectares (5.434 million acres), of which Portugal and Spain represent 56%.
The cork industry employs more than 15,000 workers in factories devoted to converting raw cork and cork byproducts into commercial products. In addition, the industry employs thousands of seasonal workers for the cork harvest and the maintenance of the oak forests.
In the prime cork-growing region of Portugal, cork oaks and their harvest are protected by law in order to protect this valuable resource and ensure the quality of the harvest.
Depending on the growing region, cork trees are harvested every nine to twelve years. The trees are not cut down and can be expected to live for 200 years. This makes the industry a near-perfect example of renewable production.
Most modern wine cork factories utilize cork dust from the processing plant to co-generate electricity. Larger scraps are reserved for use in agglomerated cork production. Virtually every piece of the wood harvested is utilized. Solid waste is minimal.
The process is repeated every decade for the life of the tree. Harvested trees normally live past 200 years. They are generally considered to be more healthy than those trees that have never been harvested.
The Cork Forest
Though the Cork Oak (Quercus suber) can flourish in many climates, the conditions that favor commercial use lie in a fairly narrow swath that cuts through Western Europe and Northern Africa along the Mediterranean coast.
The cork forest is the dominant ecosystem in much of the arid coastal areas in its range. Thriving on poor, sandy soil, the cork forest is a valuable resource that provides food and habitat for indigenous mammals and birds. The oak canopy provides cover for other flora and its deep root system protects against erosion.
Because of good husbandry practices and recent plantings, the cork forest is undergoing a period of expansion. This bodes well for the future as the cork forest will continue to provide an irreplaceable natural environment while serving the wine industry.
Cork oak forests support one of the highest levels of biodiversity among forest habitats, as well as the highest diversity of plants found anywhere in the world.
In cork oak landscapes, plant diversity can reach 135 species every square meter; many have aromatic, culinary, or medicinal value.
Cork oak landscapes contain more than 30 different brackens, some of them very rare, and cork oak microflora many species of fungus.
The fertile undergrowth is thick with heathers, leguminous plants, rock roses, and herbs.
Cork oak forests also host a rich diversity of fauna, including spiders, spadefoot toads, geckos, skinks, vipers, mongoose, wild cats, roe deer, boars, Barbary deer, and genets.
Countless millions of wintering birds from northern Europe, including virtually the entire common-crane population, shelter in cork oak landscapes in the Mediterranean.
Storks, kites, vultures, buzzards, and booted and short-toed eagles gather at bottlenecks like the straits of Gibraltar and Messina and the Bosphorus, where they can climb in thermals and cross safely.
Nearby cork oak forests are a vital haven, like the Los Alcornocales Nature Reserve in Andalusia.
Cork oak landscapes also provide crucial ecological services.
The trees help conserve soil by protecting against wind erosion and increasing the rate at which rainwater is absorbed.
Water erosion is also less in areas below upland forests that intercept rainfall, while reservoirs linked to irrigation and hydroelectric installations are protected from eroded soil.
Cork oak landscapes store carbon, reducing greenhouse gases in the atmosphere, especially in the early years of their life when they grow fast. In Spain, the Andalusian forests store more than 150 million tonnes of carbon dioxide, of which cork oak trees store nearly 11 per cent.
Cork oak trees store carbon in order to regenerate their bark, and a harvested cork oak tree absorbs up to five times more than one that is not. (WWF)