There are are approximately 600 different Quercus species across the world, six of which occur in De Waal Park:
Q. cerris (Turkey oak, mos-eik)
Q. ilex (holly oak, holm-eik)
Q. palustris (pin oak, moeras-eik)
Q. nigra (water oak, water-eik)
Q. robur (English oak, Europese eik) (See Sept 2013 Tree of the Month)
Q. suber (cork oak, kurk-eik)
Quercus suber (cork oak, kurk-eik)
This evergreen oak is of medium size, growing up to 20 meters high, though it is often quite stunted in its native environment of south-western Europe and north-west Africa. Cork oaks are considered to be soil builders and their fruits have been shown to have useful insecticidal properties. Furthermore, in parts of north-western Africa, cork oak forests are home to the endangered Barbary ape, and in Western Europe, specifically Portugal and Spain, cork oak forests are the natural habitat of the endangered Iberian lynx.
Quercus Suber Stem
Q. suber is easily recognised by its thick, insulating bark. This may have been the species’ evolutionary answer to forest fires. After a fire, while many other tree species have to regenerate from seeds or resprout from the base of the tree, the cork oak branches resprout quickly,having been protected by the cork layer. This layer grows thicker over time and when the tree is about 10 years old the cork can be harvested. A new cork layer grows again and trees are harvested about 12 times in their lifetime of between 150 and 250 years. Q. suber is is cultivated in Spain, Portugal, Algeria, Morocco, France, Italy and Tunisia and the forests cover approximately 25,000 square kilometres in total. Portugal produces about half of the world cork harvest; the trees are protected and may not be felled without authorisation.
There’s one mature cork oak in De Waal Park, just below the fountain. This specimen already has a substantial cork layer. Four of the young trees planted not far from there in the winter of 2013 are growing well.