Araucaria luxurians | Threatened Conifers of the World (en-GB)

Araucariaceae

Araucaria luxurians (Brongn. & Gris) de Laub.

One of 13 species of Araucaria endemic to New Caledonia where it occurs on the main island of Grande Terre; threats include mining, fire, erosion and urbanisation.

Description

Habit

A monoecious tree up to 40m tall, with a diameter up to 70cm at maturity. Narrowly conical or pyramidal at maturity. The thick grey bark produces a red exudate and peels in horizontal plates.

Foliage

The adult leaves are oblong, ovate, subulate or narrowly lanceolate with a rounded apex, to 1cm long, and 1–3mm wide. Adult foliage can vary In size and shape on the same branch. Foliage is usually clustered on small branches at the end of primary branches. Stomata on the outer surface (abaxial) of the adult leaves are in rows from the base to the apex. (×10 lens needed)

Cones

Female seed-cones,terminal borne on very short branches, subglobose, 10-12 x 8-10cm wide, bracts up to 10mm long, tips straight, ripening from January to mid-February. Male pollen-cones terminal in the upper part of the tree, up to 15cm long, mature from May to mid-July.

Distribution

Mainly found in the eastern and central part of the main island with one isolated population on the Îles BéIep, northwest of Grand Terre. It is estimated that the total population consist of no more than 2,500 mature individuals and that no subpopulation contains more than 250 mature trees.

Habitat and Ecology

Often found on rocky areas near the sea or inland in rocky ravines at mid elevation ranging from 1–300m above sea level. On Mont Do it has been recorded from between 800 and 1000m. Restricted to serpentine soils In maquis minier rather than closed forests. Population sizes are generally small (< 50).

Human Uses

This species is widely cultivated on New Caledonia for its ornamental value. Outside of New Caeldonia, it is very rare in cultivation and confined to botanical collections either under glass or outside in milder climates.

Conservation Status

Global status and rationale

Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v);C2a(i)

A. luxurians has a restricted distribution with an estimated extent of occurrence of less than 5,000km². The subpopulations are small and fragmented, with more than 50% separated from each other by at least 50km. There is a continuing decline in most inland subpopulations due to mining and associated activities (such as road building, spoil dumping etc.) or an increase in fires. There is a continuing decline in all parameters with some probably complete loss of certain subpopulations.

Global threats

None of the populations are protected and in places, such as Plum in the south of the main island, they are seriously threatened by fire and erosion. Mining and its activites such as road building and spoil dumping are also serious threats. Fire and the increase in settlements in other locations are also of great concern.

Conservation Actions

Currently, no subpopulations are recorded from any protected area.

References and further reading

de Laubenfels, D. J. (1972). Gymnospermes. In: Aubréville, A. & Leroy, J.-F. (eds.), Flore de la Nouvelle-Calédonie et Dépendances, 4. Paris: Muséum National d’Histoire Naturelle. 167 p.
Gaudeul, M., Rouhan, G., Gardner, M.F. & Hollingsworth, P.M. (2012). AFLP markers provide insights into the evolutionary relationships and diversification of New Caledonian Araucaria species (Araucariaceae). American journal of Botany 99(1):68-81.
Jaffré, T., Bouchet, P. & Veillon, J.–M. (1998). Threatened plants of New Caledonia: Is the system of protected areas adequate? Biodiversity & Conservation 7(1): 36.
Jaffré, T., Munzinger, J. & Lowry, P.P. (2010). Threats to the conifer species found on New Caledonia's ultramafic massifs and proposals for urgently needed measures to improve their protection. Biodiversity & Conservation 19(5):1485-1502.
Manauté, J., Jaffré, T., Veillon, J.-M. & Kranitz, M. (2003). Revue des Araucariaceae de Nouvelle-Calédonie. IRD, Nouméa.
Nasi, R. (1982). Essai pour une meilleure connaissance et une meilleure comprehension des Araucariacées dans la végétation Calédonienne. Nouméa: École Nationale des Ingénieurs des Travaux des Eaux et Forêts, Centre Technique Forestier Tropical. 134 p., 10 plates, 44 p. appendices.
Thomas, P. (2010). Araucaria luxurians. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. www.iucnredlist.org . Downloaded on 29 June 2012.