| Araucaria araucana | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Araucariales |
| Family: | Araucariaceae |
| Genus: | Araucaria |
| Section: | A. sect.Araucaria |
| Species: | A. araucana |
| Binomial name | |
| Araucaria araucana (Molina)K. Koch | |
Araucaria araucana, commonly called thepewen,monkey-puzzle,[3]pehuen orpiñonero, is anevergreen tree belonging to the familyAraucariaceae and growing to a height of 30–40 m (98–131 ft) and a trunk diameter of 1–1.5 m (3.3–4.9 ft). Native to central and southernChile and westernArgentina, it is the hardiest species in theconifer genusAraucaria.[4]
Because of the prevalence of similar species in ancient prehistory, it is sometimes called a 'living fossil'.[citation needed] It is also theofficial tree of Chile and of the neighboring Argentine province ofNeuquén. The IUCN changed its conservation status toEndangered in 2013, because logging, forest fires, and grazing have caused its population to dwindle.[1]
Theleaves are thick, tough, and scale-like, triangular, 3–4 cm (1+1⁄4–1+1⁄2 in) long,1–3 cm (1⁄2–1+1⁄4 in) broad at the base, and with sharp edges and tips. According toLusk (2001), the leaves remain attached and stay live for up to 24 years[5] and so cover almost all of the tree, except for the older branches.
It is usuallydioecious, with the male and femalecones on separate trees, though occasional individuals bear cones of both sexes. The male (pollen) cones are oblong and cucumber-shaped,4 cm (1+1⁄2 in) long at first, expanding to8–12 cm (3–4+1⁄2 in) long by5–6 cm (2–2+1⁄2 in) broad at pollen release. It is wind pollinated. The female (seed) cones, which mature in autumn about 18 months after pollination, are globose, large,12–20 cm (4+1⁄2–8 in) diameter, and hold about 200 seeds. The cones disintegrate at maturity to release the3–4 cm (1+1⁄4–1+1⁄2 in) longnut-like seeds.[citation needed]
The thick bark ofAraucaria araucana, up to 15 cm thick, may be an adaptation towildfire.[6]
The nearest extant relative isAraucaria angustifolia, a South AmericanAraucaria from Brazil and northeastern Argentina, which differs in the narrower leaves and shorter bract spines on the seed cones. Members of other sections of the genusAraucaria occur in Pacific Islands and in Australia, and includeAraucaria cunninghamii,Araucaria heterophylla, andAraucaria bidwillii.[7]
The tree's native habitat is the lower slopes of the Chilean and Argentine south-centralAndes, approximately between 1,000 m (3,300 ft) and 1,700 m (5,600 ft).[8] In theChilean Coast RangeA. araucana can be found as far south asVilla Las Araucarias (latitude 38°30' S) at an altitude of640 mAMSL.[9] Juvenile trees exhibit a broadly pyramidal or conical habit which naturally develops into the distinctive umbrella form of mature specimens as the tree ages.[10] It prefers well-drained, slightly acidic, volcanicsoil, 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 withChusquea culeou,Nothofagus dombeyi, andNothofagus pumilio, because they typically outcompeteA. araucana.[11]
Araucaria araucana is amasting species, and rodents are important consumers and dispersers of its seeds. The long-haired grass mouseAbrothrix longipilis is the most important animal responsible for dispersing the seeds ofA. araucana. This rodent buries seeds whole in locations favourable for seed germination, unlike other animals.[12][13] Another important seed dispersal agent is theaustral parakeet. 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 affected territory.[11]
Logging, long a major threat, was finally banned in 1990. Large fires burned thousands of acres of Araucaria forest in 2001–2002,[14] and areas of national parks have also burned, destroying trees over 1300 years old.[1] Overgrazing andinvasive trees are also threats.[1][14] Extensive human harvesting of piñones (Araucaria seeds) can prevent new trees from growing.[1] A Global Trees campaign project that planted2000trees found a 90 percent 10 year survival rate.[14]
Another major threat to the survival ofA. araucana, is the presence of non-native seed eating species, in particular mammals, which have been shown to severely restrict the reproduction of the tree in comparison to native seed eaters.[15] However it is still unclear as to how large a role these invasive species play in threatening this species of tree. One study in particular found that native species played a larger role in preventing reproduction through seed destruction.[16] However this may be due to the relatively recent introduction of the selected species, causing their population to be smaller than other invasive species.
A study conducted found that cattle ranching by small landowners and larger timber companies within the range ofA. araucana severely affects regeneration of seedlings.[17]
Araucaria araucana is a popular garden tree, planted for the unusual effect of its thick, "reptilian" branches with very symmetrical appearance. It prefers temperate oceanic climates with abundant rainfall, tolerating temperatures down to about −20 °C (−4 °F). It is far and away the hardiest member of its genus, and can grow well in western and centralEurope (north to theFaroe Islands andSmøla in western Norway[18]), the west coast ofNorth America (north to Baranof Island in Alaska), and locally on the east coast, as far north asLong Island, and in the southern hemisphere south of its native range to southern Chile, and also inNew Zealand and southeasternAustralia. It is tolerant of coastalsalt spray, but notair pollution.[19]
Its seeds (Mapudungun:ngulliw,Spanish:piñones) are edible,[14] similar to largepine nuts, and are harvested by indigenous peoples in Argentina and Chile.[20] The tree has some potential to be a food crop in other areas in the future, thriving in climates with cool oceanic summers, e.g., westernScotland, where other nut crops do not grow well.[21] A group of six female trees with one male for pollination could yield several thousand seeds per year. Since the cones drop, harvesting is easy. The tree, however, does not yield seeds until it is around 30–40 years old, which discourages investment in planting orchards (although yields at maturity can be immense); once established, individuals can achieve ages beyond1000years.[22][23] Pest losses to rodents andferalpigs limits the yield for human consumption and forage fattening of livestock byA. araucanamast. The tree has a high degree of inter-year variability in mast volume, and this variation is synchronous within a given area. This evolved to take advantage ofpredator satiety.[24]
Once valued because of its long, straight trunk, its current rarity and vulnerable status mean itswood is now rarely used; it is also sacred to someindigenousMapuche.[25] Timber from these trees was used for railway sleepers in order to access many industrial areas around the port of Chile. Before the tree became protected by law in 1971, some timber mills inAraucanía Region specialised in its wood.
The species is protected under Appendix I of theConvention on International Trade in Endangered Species (CITES) meaning international trade (including in parts and derivatives) is regulated by the CITES permitting system and commercial trade in wild sourced specimens is prohibited.[2]
Many young specimens and seeds were brought or sent back to the UK by Cornish miners in the nineteenth century during theCornish diaspora, and as a result Cornwall is reckoned to have a high genetic diversity of the species.[citation needed]Chris Page, aUniversity of Exeter botanist working atCamborne School of Mines (CSM), planted specimens in disusedchina clay pits in theSt Austell area as part of his research intoregreening former extractive minerals sites, which he presented in 2017 in theUK Parliament, with Professor Hylke Glass, also of CSM, as co-author.[26][better source needed]
Araucaria araucana is locallynaturalised in Great Britain, with e.g. many young self-sown trees atKyloe Woods in Northumberland.[27]
First identified by Europeans in Chile in the 1780s,[28][29] it was namedPinus araucana byJ.I. Molina in 1782.[30] In 1789,de Jussieu described a new genus calledAraucaria based on the species,[31] and in 1797,Pavón published a new description of the species which he calledAraucaria imbricata (an illegitimate name, as it did not use Molina's older species epithet).[32] Finally, in 1873, after several further redescriptions,Koch published the combinationAraucaria araucana,[33] validating Molina's species epithet in the genus. The namearaucana is derived from the nativeAraucanians who used the nuts (seeds) of the tree in Chile – a group of Araucanians living in the Andes, thePehuenches, owe their name to their diet based on the harvesting of theA. araucaria seeds; hence frompewen or its Hispanic spellingpehuén which meansAraucaria andche means people inMapudungun. They believe thepewen was given by a deity orgwenachen to nourish their offspring; manypewen gathering festivals (ngillatun) are celebrated in both Chile and Argentina in gratitude to the tree's sustenance.[34]
The origin of the popular English language name "monkey puzzle" lies in its early cultivation inBritainc. 1850, when the species was still very rare in gardens and not widely known.Sir William Molesworth, the owner of a young specimen atPencarrow garden nearBodmin,Cornwall, was showing it to a group of friends when one of them, the noted barrister andBenthamistCharles Austin, remarked"It would puzzle a monkey to climb that".[35] As the species had no existing popular name, first "monkey puzzler" then "monkey puzzle" stuck. Currently,c. 150 years later, Pencarrow has an avenue of mature monkey puzzles.[36]
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