Cork may look like the product of pulped wood, but it is in fact the bark of a Cork Oak. It is a renewable resource grown in Spain and Portugal, but is being replaced by plastics and other artificial cork materials.
The process for harvesting cork is very manual and there is, as of yet, no other way to harvest it. It begins with a tree at just over 25 years old, the starting age for cork. Workers, known as extractors, start by cutting the bark around the circumference and vertically using a sharp axe. This is the most difficult aspect of cork harvesting as cutting too far can damage the pericambium, responsible for regrowth of bark, killing the tree. The axe is then used for leverage to free the cork from the tree, but this also must be done gently and precisely to prevent the death of the tree or damage to the product.
While most alternatives to trees have allowed for more tree growth, alternatives to natural cork are actually causing a decline in Cork Oaks. Arguments for cork alternatives are certainly compelling, from mold reduction to better seals. Removal of the Cork Oak could have bad results for the areas they are grown in. Some of the trees are hundreds of years old, and all of them protect the soil from erosion and extreme drought (which is a common issue in the area).
But with demand dropping, many farms have closed down with the trees being removed, leaving the future of the Cork Oak uncertain.