The cork oak (Quercus saber) is the national tree of Portugal. Though protected by law, their numbers are dwindling due to climate change and bad land management practices. As they grow, cork oaks can assume extremely graceful and un-natural forms. Each tree has a clear, distinct personality. Apart from the bark, which is harvested every nine years by skilled laborers, cork oaks also provide shade for cattle and acorns that are eaten by the famous Iberian pigs. It is the oil of the acorn of cork and holm oaks that gives Iberian ham its distinct taste and health benefits.