Araucaria araucana, commonly called the monkey puzzle tree, monkey tail tree, piñonero, pewen or Chilean pine, is an evergreen tree growing to a trunk diameter of and a height of . It is native to central and southern Chile and western Argentina. It is the hardiest species in the conifer genus Araucaria. Because of the prevalence of similar species in ancient prehistory, it is sometimes called a living fossil. It is also the national tree of Chile. Its conservation status was changed to Endangered by the IUCN in 2013 due to the dwindling population caused by logging, forest fires, and grazing.
Description
The leaves are thick, tough, and scale-like, triangular, long, broad at the base, and with sharp edges and tips. According to Lusk, the leaves have an average lifespan of 24 years and so cover most of the tree except for the older branches.
It is usually dioecious, with the male and female cones on separate trees, though occasional individuals bear cones of both sexes. The male (pollen) cones are oblong and cucumber-shaped, long at first, expanding to long by broad at pollen release. It is wind pollinated. The female (seed) cones, which mature in autumn about 18 months after pollination, are globose, large, in diameter, and hold about 200 seeds. The cones disintegrate at maturity to release the long nut-like seeds.
The thick bark of Araucaria araucana may be an adaptation to wildfire.
Habitat
The tree's native habitat is the lower slopes of the Chilean and Argentine south-central Andes, typically above . In the Chilean Coast Range A. araucana can be found as far south as Villa Las Araucarias (latitude 38°30' S) at an altitude of 640 m asl. Juvenile trees exhibit a broadly pyramidal or conical habit which naturally develops into the distinctive umbrella form of mature specimens as the tree ages. It prefers well-drained, slightly acidic, volcanic soil, but will tolerate almost any soil type provided it drains well. Seedlings are often not competitive enough to survive unless grown in a canopy gap or exposed isolated area. It is almost never found together with Chusquea culeou, Nothofagus dombeyi, and Nothofagus pumilio, because they typically outcompete A. araucana.
Seed dispersal
Araucaria araucana is a masting species, and rodents are important consumers and dispersers of its seeds. The long-haired grass mouse, Abrothrix longipilis, is the most important animal responsible for dispersing the seeds of A.araucana. This rodent buries seeds whole in locations favorable for seed germination, unlike other animals.
Another important seed dispersal agent is the parakeet species Enicognathus ferrugineus. Adult trees are highly resistant to large ecological disturbances caused by volcanic activity, after events like these the parakeets play their role by dispersing the seeds far from effected territory.
Threats
Logging, long a major threat, was finally banned in 1990. Large fires burned thousands of acres of Araucaria forest in 2001–2002, and areas of national parks have also burned, destroying trees over 1300 years old. Overgrazing and invasive trees are also threats. Extensive human harvesting of piñones (Araucaria seeds) can prevent new trees from growing. A Global Trees Campaign project that planted 2000 trees found a 90percent 10-year survival rate.
Cultivation and uses
Araucaria araucana is a popular garden tree, planted for the unusual effect of its thick, "reptilian" branches with very symmetrical appearance. It prefers temperate climates with abundant rainfall, tolerating temperatures down to about . It is far and away the hardiest member of its genus, and can grow well in western and central Europe (north to the Faroe Islands and Smøla in western Norway), the west coast of North America (north to Baranof Island in Alaska), and locally on the east coast, as far north as Long Island, and in New Zealand, southeastern Australia and south east Ireland. It is tolerant of coastal salt spray, but does not tolerate exposure to pollution.