Cork trees in the Alentejo
The bark of the cork oak tree is rugged, hardy and extremely thick and is known as cork and it is this cork which is harvested in Portugal every 9 years and its widespread production has led Portugal to become the leading cork producer in the world. One very significant reason for the continued ample production of cork is because of the fact that once the cork is removed from the tree, a newer layer begins to grow again and therefore this resource is constantly replaced once removed therefore confirming continuous production. In Portugal, cork oak trees are preserved and cutting them down is illegal unless it is sanctioned by the forestry department for the curbing of unproductive trees. Cork harvesting is more of a natural process and it is estimated that these cork oak trees can live for over 150 years and the first cork are obtained from its bark when the tree is about 25 years of age and then harvested for over a century.
It has been estimated that a whopping 16% of the total foreign income in Portugal is accumulated from the export of cork.