Araucaria montana Brongn. & Gris

Araucariaceae

One of 13 species of Araucaria endemic to New Caledonia where it occurs on the main island of Grande Terre and although widespread is under considerable threat from mining and fire.

Description

Habit

A monoecious tree up to 40m tall, with a d.b.h. up to 1m when mature. Pyramidal when young and developing a very distinct open, candelabriform crown with a clear bole as it matures. Bark thick, light grey and often peeling in horizontal plates.

Foliage

Adult leaves 1–2.5 x 1–2cm, lanceolate to ovate with an acute apex; stomata in bands at the base and apex of the leaf along the upper surface of leaf. Foliage usually clustered on small branches at the end of primary branches.

Cones

Female seed-cones up to 12cm long, terminal, borne on very short branches; bracts with prominent tips to 1cm; maturing January and February. Male pollen-cones 8–25cm long, terminal, maturing July to August.

Key Characters

A. montana can be confused with A. laubenfelsii, however, the different stomatal patterns on the upper leaf surface (seen through a hand lens) can be used to distinguish them. In A.montana they are only present at the base and apex of the leaf and are not organised in bands, whereas in A. laubenfelsii they are in intermittent rows organised into bands of 3–5 rows each and most of the rows extend throughout the length of the leaf, or at least from the base to the middle.

Distribution

Endemic to New Caledonia where it occurs in scattered subpopulations throughout the main island of Grande Terre. An isolated subpopulation occurs on the Ile d'Art. Subpopulations can be locally extensive and cover several square kilometers.

Habitat and Ecology

Generally in the maquis minier vegetation on nickel rich soils, usually at altitudes ranging from 500 to 1,400m. At lower altitudes (e.g. Mt Panie), it also occurs in humid dense forests. Occasionally it occurs with A. rulei and A laubenfelsii. In some serpentine areas it may form extensive, open stands spread over several kilometers.

Conservation Status

Global status and rationale

Vulnerable A3c;B1ab(i,ii,iii,iv,v)

This is the most widespread Araucaria species on New Caledonia. However, the majority of subpopulations, have been and will continue to be affected by mining activities. It meets the criteria for Vulnerable on account of its current extent of occurrence, fragmentation, a continuing decline in the area of occupancy, extent of occurrence and quality of habitat together with a projected 30% decline in total population within the next 100 years.

Global threats

Open cast mining, its associated activities and an increase in fire frequencies are the main threats to this species except in locations in the north east where it is unlikely that mining will occur.

Conservation Actions

Very few stands are within protected areas and many more have been disturbed by mining activities