Hugh Powell reminds us of the connection between wine bottle closures and the preservation of biodiversity. Cork prices are crashing, which threatens cork oak plantations on the Iberian peninsula.

Cork trees live for about 250 years, growing in open groves interspersed with meadows of tawny grasses and diverse wildflowers. Once a decade, skilled workers with hatchets carefully slice off an inch-thick jacket of bark, leaving the tree to grow it back. There are cork farmers right now slicing cork from the same trees that their great, great, great grandparents harvested. In all, some 13 billion corks are produced each year, slightly more than half of them in Portugal and the rest in Spain, France, Italy, Morocco, Algeria, and Tunisia. It’s a $2 billion industry.

The skilled labor pays well, and the farmers can also keep livestock on the land. While they’re at it, the farmers keep a delicate balance in their forests, avoiding overgrazing but keeping shrubs from taking over, setting controlled fires and putting out fierce ones.

Among conservationists there’s a real fear that as cork prices fall, the cork oak forests will deteriorate or be converted into eucalyptus plantations or Mediterranean resorts.