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کشاورز ایرانی (مرکز ارائه خدمات جامع آموزش کشاورزی) - تیره کاج مطبق araucariaceae

کشاورز ایرانی (مرکز ارائه خدمات جامع آموزش کشاورزی)

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شنبه 20 تیر 1388

تیره کاج مطبق araucariaceae

نویسنده: مهندس علیرضا شعاعی   طبقه بندی: گیاه شناسی، 

                                                     تیره کاج مطبق araucariaceae

این تیره دارای دو جنس و 36 گونه است. در این گیاهان فلس برچه ای چسبیده است و منحصرا دارای یک تخمک به طور واژگون است. بصورت درختانی بزرگ هستند که بیشتر در نیمکره جنوبی انتشار دارند . از این تیره گونه کاج مطبقaraucaria heterophylla   بسیار زیباست. این جنس مخصوص مناطق گرمسیری است. گونه A. excelsa  در شمال کشور یادر گلدان پرورش داده میشود .

MY FAVOURITE TREE

by Magnus Smyly

My favourite tree at Westonbirt, a towering monkey puzzle (Araucaria araucana) succumbed to honey fungus in Spring 2003. There are several other younger specimens at Westonbirt - both near to where this original tree stood in Savill Glade and also in Silk Wood. However, this one was an original of seven planted by Robert Holford during the 1850s and 1860s, each sapling having cost £20. To put this in context, around the same time the Holfords purchased four giant redwood (Sequiadendron giganteum) for £6 each from Veitch’s nursery in Chelsea.

Archibald Menzies introduced the monkey puzzle tree into Britain in 1795, allegedly having pocketed fertile seeds of the tree when offered them as a dessert while dining with the Governor of Chile on a global circumnavigation, sowing and growing the seeds on his return voyage. Five of the seedlings made it back to Britain and were presented to Kew Gardens, the last surviving until 1892. During the first part of the 19th century, monkey puzzle trees were a prized asset and status symbol of wealthy landowners. A major import of monkey puzzle seeds to Britain took place following a trip by William Lobb in 1840 to Chile, sponsored by Veitch’s nursery, leading to advertisements in the Gardener’s Chronicle in 1843 offering 4-year old trees.

Monkey puzzle can be both male and female trees (dioecious) - at the time of planting the sex of the tree cannot be known and the planter has to wait 40 odd years for the tree to mature and fruit. The male tree bears long, pointed cones 4”x2.5” (10x6cm), which exist in sets at the tips of branches, having a brown appearance following the dispersal of pollen from densely packed scales. The female tree carries large bright green ball-like cones 4-7.5” (10-18cm) long, weighing up to 2.2lbs (1kg), which appear in spring and ‘explode’ shedding their seeds in August or September the following year. The explosion - and owners of female trees have noted the noise - cause up to 200 wingless seeds to shower down. They are edible, and fertile when male and female trees grow relatively close to each other. Rarely, monkey puzzle specimens are found that have both male and female branches (monoecious).

 

Male cones © Magnus Smyly

Monkey puzzle is a member of the Araucariaceae family of conifer, which consists of 18 species. Norfolk Island pine (Araucaria heterophylla), Bunya-Bunya (Araucaria bidwillii) and Moreton Bay pine (Hoop pine; Araucaria cunninghamii) are other species of the genus, (see Daniel Luscombe’s article in Holfordiana No. 53). In May this year at Kew Gardens, the close relation Wollemi pine (Wollemia nobilis) was displayed.

There are only around 100 specimens existing in the wild, having thought to be extinct for 2 million years until it was rediscovered 11 years ago. Monkey puzzle is itself an old species - having existed during the Jurassic period of the dinosaurs.

The surviving native forests of the monkey puzzle are located south of Santiago in Chile and across the Andes in Argentina, between 37°27’ and 40°48’, and a genetically distinct population in the Pacific coastal mountain range Cordillera de Nahuelbuta in Chile, between 37°40’ and 38°40’.

Whilst monkey puzzle trees are more widespread in Chile, they are threatened by commercial forestry endangering their natural habitat, and by fires, caused naturally by lightning and the volcanic environment, and allegedly by man intentionally. Due to these pressures, since 1990 the Chilean monkey puzzle tree is listed on the Convention on International Trade in Endangered Species (CITES).

The International Union for Conservation of Nature and Natural Resources (IUCN) lists the monkey puzzle tree on its ‘Red List’ as ‘Vulnerable’ due to selective logging, clear cutting and fires.

My wife and I were fortunate to be able to visit Chile in August 2004 - at the close of the Chilean winter - and managed to visit the Andes area but not the coastal range. From our touring around Temuco, it is clear that little native forest exists outside of National Parks and Reserves, with the land cleared for farming or commercial forestry using faster growing Monterey pine (Pinus radiata) and eucalyptus (Eucalyptus). We visited Parque National Conguillio surrounding the volcano Llaima, and were able to witness how the lava flows from the 1994 eruption had swept through the native forest. The volcanic eruptions can cause forest fires, which due to the fire resistant properties of monkey puzzle trees, in particular their thick bark, allows them to survive the quicker growing, but less fire resistant, competition from the Southern Beech (Nothofagus pumilio). We saw several examples of young monkey puzzle trees already growing on the solidified lava flow (see below).

Although Conguillio is probably the best place in Chile to see Andean monkey puzzle trees, the snow meant our trip through Reserva Nacional Malalcahuello-Nalcas led us further into the centre of a monkey puzzle tree forest. It was here that we were able to gauge the size that fully mature monkey puzzle trees can grow - reaching up to 7ft (2m) in diameter and up to 165ft (50m) tall. They can live up to 2,000 years old in this environment.

Monkey puzzle, seven foot in diameter © Magnus Smyly

The native people of Chile in this area - the Pehuenche - revere the monkey puzzle as a tree left on earth by God for them. Indeed, their name - Pehuenche means people of the Pehuen, or monkey puzzle. Traditionally, their livelihoods depended upon monkey puzzle trees as their diet was based on the seeds (pinones) that they collected during the harvest season, with a single family collecting up to 8,800lb (4,000kg) each year. The Pehuenche have a special ceremony at the time of the summer solstice (21 January) to ensure that the next harvest will be plentiful, and they have been a collective voice calling for the protection of their precious tree.

Whilst the Andean population has suffered severely, the greatest concern is for the distinct coastal population, which in the majority is held in private hands. There is hope. Home Depot, the US based largest retailer of lumber in the world, buys almost 10% of Chile’s annual wood exports, and has mediated between timber producers and Chilean environmentalists to agree a forestry accord to protect the native Chilean forests. At a lower level, whilst in Chile, I met Ned Holburn, Political Secretary to the British Embassy to Chile in Santiago to discuss the monkey puzzle’s plight.

Since the Chilean monkey puzzle is a protected tree but not its environment, a consortium including the International Conifer Conservation Programme (ICCP) based at the Royal Botanical Gardens Edinburgh has acquired 323 hectares of land to comprise the new Nasampulli Reserve. It is hoped that this Reserve, after further acquisitions, will form a corridor between existing nationals parks and reserves for the Andean population of Araucaria arauana.

Whilst my favourite tree at Westonbirt has now long gone, acquired by a wood turner to utilise the beauty of the whorls, the species remains popular all over Britain in parks and gardens, and strives to exist in its native habitat alongside mankind.

Bibliography: Ancient Trees - Trees that last a thousand years, Anna Lewington & Edward Parker monkey puzzle - Sage Press (Available from www.treefinders.co.uk)

 
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