Libocedrus yateensis | Threatened Conifers of the World (en-GB)

Cupressaceae

Libocedrus yateensis Guillaumin

One of three species of Libocedrus endemic to New Caledonia where it occurs in only three locations and is threatened by fire

Description

Habit

Spreading shrub or small tree 2–10m tall, monoecious; usually multistemmed. Bark coarse and scaly, exfoliating in thin irregular strips or plates, reddish brown. Branches many, spreading or ascending, often twisted, forming a conical young tree but bushy, often with a rounded crown when mature.

Foliage

Forming dense sprays, flattened, ca. 4mm wide. Leaves arranged in opposite pairs at right angles to those above or below with the facial (central) and laterial pairs almost equal in size, 2–5 x 1–2mm, olive-green, stomatal band glaucous white.

Cones

Male pollen-cones terminal, solitary, 5–8 x 2–2.5mm, cylindrical, yellowish green, light brown when mature. Female seed-cones terminal, borne on branchlets with leaves of similar shape and size; bract-scales, the upper pair 8–9 x 3–4mm, the lower, smaller pair 4–6 x 2mm; seeds 1–-2, ovoid–oblong, flattish, apex acute or biid, light brown, with two opposite, very unequal, membranous wings.

Key characters

Libocedrus yateensis is very similar to L. austrocaledonica and differes in some minor details in that the apex of the facial leaves which are pointed and reaches the next facial leaf (in L. austrocaledonica the apex is blunt and it only reaches halfway). The latter could represent a higher altitude form of L. yateensis (Farjon, 2005)

Distribution

Endemic to New Caledonia on the mian island of Grande Terre. The species is sparsely distributed in two river valleys (Rivière Bleue and Rivière Quinnée) in the southern part of the island ultramafic massifs and a single northern location near to Povila. Records from Roche Ouaieme (Jaffre et al., 1987) have been re-identified as Libocedrus chevalieri (Farjon 2005). Subpopulations are small and localized with little regeneration.

Habitat and Ecology

Grows in riparian habitats in lowland forest. Occurs at altitudes of between 150 to 600m.

Conservation Status

Global assessment

Endangered B2ab(iii)

Global rationale

Libocedrus yateensis is assessed as Endangered as its area of occupancy is estimated to be 24km², only three locations are known which are severely fragmented and there is a decline in the quality of its habitat is due to the effects of fire and a lack of regeneration.

Global threats

Fire is a threat throughout its range.

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.
Farjon, A. (2005). A Monograph of Cupressaceae and Sciadopitys. The Royal Botanic Gardens, Kew.
Jaffre, T., Veillon, J.M. & Cherrier, J.F. (1987). On the occurence of two Cupressaceae, Neocallitropsis pancheri and Libocedrus austrocaledonica in the Mt Paéua area and new sites for the gymnospems in New Caledonia. Bulletin de Museum National d'Histoire Naturelle Section B Adansonia 9(3): 273-288.
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.
Suprin, B. (2011). Florilège des plantes en Nouvelle-Calédonie. Tome 1. Éditions Photosynthèse. 519 pp.
Thomas, P. (2010). Libocedrus yateensis. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. www.iucnredlist.org. Downloaded on 29 June 2012.
Tomlinson, P.B., Takaso, T., & Cameron, E.K. (1993). Cone development in Libocedrus (Cupressaceae): phenological and morphological aspects. Am. J. Bot. 80:649–659