Araucaria bernieri, commonly known as Bernier's columnar araucaria or Bernier's araucaria, is a species of conifer in the family Araucariaceae. It is endemic to New Caledonia.
Taxonomy and Nomenclature
The species was first described by John Theodore Buchholz in 1949, published in Bulletin du Muséum National d'Histoire Naturelle (série 2, 21: 280). A synonym is Eutassa bernieri (J.T. Buchholz) de Laub. (2009). A molecular analysis places Araucaria bernieri into the clade of small-leaved species of New Caledonia, along with A. schmidii, A. scopulorum, and A. subulata.
Description
Araucaria bernieri is a monoecious evergreen tree reaching 40–50 meters (up to 55 m) in height, with a trunk diameter of up to 1 meter at breast height. Specimens growing on poorer soil tend to be dwarfed, sometimes reaching only 4 meters at maturity in northern areas. The crown is narrowly columnar and open, with closely spaced tiers of slender, horizontal branches. The bark is gray, exfoliating in horizontal strips, forming horizontal bands or ridges.
Adult leaves are scale-like, imbricate, broadly ovate, 2–3.5 mm long and 1.5–2.5 mm wide, three-edged and incurved with an acute or obtuse apex, leathery and smooth, prominently keeled beneath. Juvenile leaves are triangular, needle-like, up to 7 mm long, with a sharply acute apex.
Male pollen cones are 35–90 mm long and 8.5–16 mm wide, cylindrical, initially erect but pendulous when shedding pollen, with a bluish-white glaucous bloom. Female seed cones are 8–11 cm long and 6.5–8 cm wide, subglobose, green when mature, with a glaucous waxy coating. Seeds are up to 3 cm long.
Distribution and Habitat
Araucaria bernieri is found only in New Caledonia on the main island of Grande Terre. It is mainly confined to areas of moist evergreen forest on the slopes of lower mountains in the southern part of the island, south of 21.5°S, at elevations below 700 meters. Records from Poum and Tiebaghi in the north have been re-identified as A. scopulorum.
The species is commonly found in evergreen rainforest on slopes of lower mountains. It does not form dense stands but rather occurs as scattered individual trees that emerge well above the closed canopy of the forest, sometimes in association with A. subulata. It is restricted to soils derived from ultramafic rock (peridotite and serpentine) with a high content of heavy metals such as iron, manganese, and nickel.
Conservation Status
Araucaria bernieri is listed as Vulnerable on the IUCN Red List of Threatened Species (2024 assessment). The total population is estimated to be less than 10,000 mature individuals. A decline of 10% over the next 100 years is projected based on the likelihood of losses through fire and activities associated with mining. The species is threatened by habitat loss, with major threats including activities associated with mining (road building, waste storage) and fires that prevent regeneration or expansion of remnant stands. In the past, the species was also under pressure from logging.
The species is represented in protected areas including Rivière Bleue Provincial Park and Montagne des Sources Nature Reserve. Northern subpopulations are all outside of protected areas and vulnerable to mining activities.
