Lagarostrobos

Lagarostrobos franklinii is a species of conifer native to the wet southwestern corner of Tasmania, Australia. It is often known as the Huon pine or Macquarie pine, although it is actually a podocarp (Podocarpaceae), not a true pine (Pinaceae).[2][1] It is the sole species in the genus Lagarostrobos; one other species L. colensoi (endemic to New Zealand) formerly included has been transferred to a new genus Manoao. The genus was also formerly included in a broader circumscription of the genus Dacrydium.[3]

Lagarostrobos
Huon pine in a Tasmanian botanical garden
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Podocarpaceae
Genus: Lagarostrobos
Quinn
Species:
L. franklinii
Binomial name
Lagarostrobos franklinii
(Hook.f.) Quinn

In molecular phylogenetic analyses Lagorostrobos was found to be related to Parasitaxus (a parasitic and monotypic genus from New Caledonia) and Manoao, but their exact relationships are unresolved.[4]

The wood is highly prized for its golden yellow colour, fine grain, and natural oils that resist rotting. The chemical giving the timber its unique smell and preservative qualities is methyl eugenol.

It has been planted in the grounds of Crathes Castle, Aberdeenshire, Scotland and has done well. Two healthy specimens can also be found at Torosay Castle, Isle of Mull.[5]

Description
Close-up of Huon pine foliage

It is a slow-growing, but long-lived tree; some living specimens of this tree are in excess of 2000 years old.[6] It grows to 10 to 20 m tall, exceptionally reaching 30 m, with arching branches and pendulous branchlets. The leaves are spirally arranged, very small and scale-like, 1 to 3 mm long, covering the shoots completely. It is dioecious, with male (pollen) and female (seed) cones on separate plants. The male cones are yellow, 5 to 8 mm long and 1 to 2 mm broad. The mature seed cones are highly modified, berry-like, with 5 to 10 lax, open scales which mature in 6–8 months, with one seed 2 to 2.5 mm long on each scale. Unlike the closely related New Zealand genus Manoao, the scales do not become fleshy and are water-dispersed, not bird-dispersed.[2]

Based on herbarium specimens the extent of occurrence is estimated to be around 13,363 km2 with an estimated area of occupancy of 825 km2. The actual area of occupancy is estimated to range from 2,500 ha (Gibson 1991) to as much as 10,500 ha (Parks and Wildlife Service Tasmania 2006).[1]

Age

Huon pines are some of the oldest living organisms on the Earth.

A stand of trees in excess of 10,500 years old was recently found in western Tasmania on Mount Read.[7] Each of the trees in this stand is a genetically identical male that has reproduced vegetatively. Although no single tree in this stand is of that age, the stand itself as a single organism has existed that long.[8]

Individual trees in the clonal patch have been listed as having ages of 2000[6][9] or even to 3000[10][11] years old.

Because of the long life of individual trees, tree rings from Huon Pine have been used for dendrochronology to establish a record of climate variation.[12]

Conservation

An estimated 15% of its habitat has been lost through inundation for hydroelectric schemes and to fire over the past 100 years or so. Extensive logging in the past has removed nearly all large trees, but there is regrowth nearly everywhere. One stand of the species has been made available for access to craft wood from dead and downed timber under a strict licensing system. It is illegal to cut living trees.[1]

See also

References
  1. Farjon, A. (2013). "Lagarostrobos franklinii". IUCN Red List of Threatened Species. 2013: e.T34153A2848138. doi:10.2305/IUCN.UK.2013-1.RLTS.T34153A2848138.en. Retrieved 11 January 2020.
  2. Molloy, B. P. J. (1995). "Manoao (Podocarpaceae), a new monotypic conifer genus endemic to New Zealand" (PDF). New Zealand Journal of Botany. 33 (2): 183–201. doi:10.1080/0028825x.1995.10410483. Archived from the original (PDF) on 2005-09-30.
  3. Quinn, C. J. (1982). "Taxonomy of Dacrydium Sol. ex Lamb". Australian Journal of Botany. 30 (3): 311–320. doi:10.1071/bt9820311.
  4. Sinclair, W. T., R. R. Mill, M. F. Gardner, P. Woltz, T. Jaffré, J. Preston, M. L. Hollingsworth, A. Ponge, and M. Möller. (2002) Evolutionary Relationships of the New Caledonian Heterotrophic Conifer Parasitaxus Ustus (Podocarpaceae), Inferred from Chloroplast trnL-F Intron/Spacer and Nuclear ITS2 Sequences. Plant Systematics and Evolution 233: 79–104.
  5. "Half-hardy trees in Britain and Ireland - part two". Royal Horticultural Society. Archived from the original on 2013-03-11. Retrieved 2009-06-18.
  6. "Plants - Huon pine : one of the oldest plants on earth". Parks and Wildlife Service Tasmania. 2003.
  7. Graham Lloyd, "The oldest tree", The Australian, September 10, 2011. Retrieved 2018-03-22.
  8. "Could a tree be 10,000 years old?". Gumnuts - the ASGAP Blog. Archived from the original on 2007-04-12. Retrieved 2012-09-19.
  9. Cris Brack and Matthew Brookhouse, Where the old things are: Australia’s most ancient trees", The Conversation, April 17, 2017: "the oldest in Australia could be a Huon pine (Lagarostrobos franklinii) in Tasmania, the oldest stem of which is up to 2,000 years old." Retrieved 2018-03-22.
  10. Huon Pine Lagarostrobos franklinni", Department of Primary Industries, Parks, Water and Environment, 2011: "Individuals have been known to reach an age of 3,000 years." Retrieved 2018-03-22.
  11. Quinn, Lagarostrobos franklinii, The Gymnosperm Database, 1982: "Living trees sampled by increment borer have yielded ring counted ages of up to 2500 years, and since these were not pith dates, it seems likely that there are living trees with ages in excess of 3000 years (Balmer 1999)." Retrieved 2018-03-22.
  12. Cook, E.R., Francey, R.J., Buckley, B.M. and D'Arrigo, R.D., "Recent increases in Tasmanian Huon pine ring widths from a subalpine stand: natural climate variability, CO2 fertilisation, or greenhouse warming?", Papers and Proceedings of the Royal Society of Tasmania, vol. 130(2), 1996, pp. 65-72. ISSN 0080-4703. Retrieved 2018-03-22.
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