The biodiversity of cork forests
The second-highest number of endemic plant species in the world
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 metre; 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.
Wintering birds
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.
Vital 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 isn’t.
Spain’s dehesa
The dehesa (woodland pasture) of south-west Spain is an excellent illustration of the environmental services provided by cork oak landscapes.
It mainly comprises mixed formations of oak species dominated by holm and cork oak. The diversified production found in the dehesa includes acorns, tannin, fodder, firewood, crops, honey, aromatic plants, cork, livestock, and game.
The dehesa has been managed by people for centuries, yet the woodland cover has survived the use of its natural resources.
Environmental value of the dehesa:
It mainly comprises mixed formations of oak species dominated by holm and cork oak. The diversified production found in the dehesa includes acorns, tannin, fodder, firewood, crops, honey, aromatic plants, cork, livestock, and game.
The dehesa has been managed by people for centuries, yet the woodland cover has survived the use of its natural resources.
Environmental value of the dehesa:
- Trees create a microclimate less extreme in both winter and summer.
- The dehesa retains water due to porosity and organic content, preventing soil erosion.
- Wind speed and erosion are reduced.
- Trees supply large amounts of material which rots as humus into the upper soil. Nutrients are also drawn from lower to upper soil.
- Forest fires are reduced.
- Migrating birds can nest and breed.