The cork oak trees are not only regenerative, but they do not require fertiliser, pesticides, irrigation or pruning. In Portugal, cork oaks store 17,500 tonnes of carbon in above and below ground biomass. Once the bark is harvested, the tree actually absorbs up to 5 times more carbon dioxide than usual to help the restoration process. The stripped trees release so much oxygen they are referred to in Portugal as the ‘lungs’ of the environment. WWF says ‘Cork oak forests support one of the highest levels of biodiversity among forest habitats, as well as the highest diversity of plants found anywhere in the world.’