Evergreen and ornamental, the Quercus suber is stripped for its thick, corky bark every 10-12 years.
Medium-sized for an oak tree, this species is the primary source of wine bottle stoppers and cork-flooring making use of its spongy, breathable quality. Harvesting the cork in Spring and Summer doesn’t harm the tree; it is replaced soon after with a new layer.
Harvesting is a process that actually improves the health and vigor of the tree-trunk which tends to flourish with regeneration, thus, even today cork is still harvested entirely without machinery; it is a skill delicately performed by hand using traditional techniques with a special cork-stripping axe designed for the job.
One key factor regarding the cork harvest is that the tree has to be in full growth at the correct time of season and this will not damage the cork material or the tree – isn’t it odd that manual labour is still the cleanest, quickest and most efficient method available?
Cork oaks are trees that can live up to 250 years or more. The first harvest must be no sooner than 25 years to give the material a chance to mature and then the tree goes on a 12 year harvesting cycle; the cork is removed maybe a dozen times in the lifetime of a strong tree.
Forests of this type – cork oak – can support diverse ecosystems such as the Barbary Macaque in North Africa and the endangered Iberian Lynx which is on the protected species list in Western Europe; cork oak forests keep a great many insect species as well as birds that live in the canopy.
30 million years in the making, this marvelous oak tree is responsible for the ingenious device attached to the top of your bottle of wine; cork has been used for thousands of years dating back to ancient Egypt where it was used for insulation and in China (originally) to fish with!
Nowadays, this oak tree is a national treasure to the Portuguese who are the world’s largest manufacturer of cork; the lightweight and elastic property of this unique material can be used for flooring, manufacture of furniture and in many forms of footwear.
Forest mosaics often have cork oaks near other oak species such as pines and even wild olive trees in areas of great species diversity which extends to animal life and many plants.
Kew Gardens has over 60 samples of cork oak including artifacts. In Britain however, the tree is not commercially grown and used simply for the ornamental value; the main novelty value of this oak tree is the year round display of leaves that our native oaks do not have!