Cork is the outer bark of the evergreen cork oak (Quercus suber). This variety of oak grows mainly in Portugal, Spain, southern France, Italy, and North Africa.Cork is sustainable. It is harvested by stripping the bark every nine years. Each cork oak tree provides an average of 16 harvests over its 150-200 year lifespan.Cork harvesting is one of the best examples of a sustainable agro-forestry system where people use the natural resources around them without disturbing or destroying nature. Cork harvesting has been a way of life in the Mediterranean for at least a thousand years. The forests are ancient.The World Wildlife Fund (WWF) urged Portugal and other countries to expand their cork forest to act as a barrier against the encroachment of the desert due to global warming. The WWF asserts that in Portugal and Spain cork oak landscapes are important homes to Iberian Lynx (the world's most endangered big cat with only 100 thought to survive), the Spanish Imperial Eagle (with only 150 pairs thought to survive), and in North Africa the Barbary Deer (with only about 200 remaining). Plus, the acorns of the Cork Oak is food for many animals in the wild and is also used for feeding swine and other livestock.Harvesting cork is a highly skilled job; even the axes are specially designed. Cork cutters make precise incisions into the cork bark and then strip it off the trees - like peeling the skin away from a banana. An experienced worker can gather up to 1,300 lbs. of cork each day.After harvest, each tree is painted with a big white number to indicate when it was last stripped. The trees are left for nine years to allow the cork bark to grow back and then the whole process starts again.After the wine corks are cut from the bark, the remaining cork is used to make flooring. Therefore, many of the cork granules used in cork flooring and underlayment are recycled from the wine cork industry.