Distribution

Endemic to Papua New Guinea. Occurs in the central mountain range from an isolated subpopulation on the Wamira River in the east through the Owen Stanley Range and the Bismarck Range, with other isolated stands near Sattelburg on the Huon Peninsula and on the Tagari River in the Central Highlands. It occurs within a narrow band of 5 degrees of latitude, from Jimmi River (520 m is its lowest recorded altitudinal

occurrence) in the north to Weigane River in the south. It does not occur in West Papua, the Indonesian western half of New Guinea. Its estimated extent of occurrence is more than 20,000 km² while the area of occupancy is likely to be less than 2,000 km². It is known from more than 10 locations.

It occurs in scattered stands, usually as an emergent.

Habitat and Ecology

Araucaria hunsteinii is recorded to be the tallest tree in Malesia, reaching 90 m in height. It occurs in two types of forest, a drier and a wetter one; in the drier type the canopy of angiosperms reaches only 15–25 m of average height,with A. hunsteinii attaining twice that height. Associated common evergreen tree species in this forest type are Aleurites moluccana (L.) Willd. (Euphorbiaceae), Celtis latifolia Planch. (Celtidaceae), Heritiera sp. (Haemadoraceae), Macaranga sp. (Euphorbiaceae) and Pouteria luzonensis (Merr.) Baehni (Sapotaceae); deciduous species are Garuga floribunda Decne. (Burseraceae), Protium macgregorii (F.M. Bailey) Leenh. (Burseraceae), Sterculia sp. (Sterculiaceae) and Terminalia sp. (Combretaceae) (Enright 1982).

In high rainfall localities both angiosperms and A. hunsteinii become much taller, with the conifer towering to 60–90 m. Common associated canopy tree species are Acmena sp. (Myrtaceae), Elmerrillia papuana Dandy (Magnoliaceae), Flindersia amboinensis Poir. and F. pimenteliana F. Muell. (Rutaceae), Pometia pinnata J.R. & G.Forst. (Sapindaceae) and Xanthophyllum papuanum Whitmore ex van der Meijden (Polygalaceae). Cerbera floribunda K.Schum. (Apocynaceae), Cryptocarya sp. (Lauraceae), Dysoxylum sp. (Meliaceae), Gnetum gnemon L. (Gnetaceae), Litsea sp. (Lauraceae) and Myristica sp. (Myristicaceae) are common in the subcanopy tree layer (Enright 1982). Soils are neutral to acidic with a high clay content. Precipitation
ranges from 800 mm to more than 4,000 mm per annum, the species occurs mainly in Fagaceae forest between 520 and 2,100 m although the majority of stands occur between 750 and 1,700 m.

Conservation Status

Global Status & Rationale

Near Threatened

A. hunsteinii's extent of occurrence is estimated to be more than 20,000 km². Although no reliable estimates exist for its area of occupancy, it is likely to be less than 2,000 km². It is known from more than 10 locations and the populations are not yet severely fragmented in the context of the IUCN definitions. While there has been significant historic exploitation for its timber and recent losses due to fires, the extent of this decline is uncertain although it is likely to be at least 30%. In the absence of better information an assessment of Near Threatened is appropriate (it almost qualifies for listing as threatened under criteria A2cd and B2ab(iii)).

Global threats

In most parts of its range, it has been reduced to scattered stands following heavy exploitation for its good-quality timber. It is also locally threatened by shifting agriculture and damage caused by feral pigs. Fire associated with shifting agriculture and periodic El Nino induced droughts is a particular threat: large stands in McAdam National Park were burnt in September 1997. The extent of its decline is uncertain as is the degree of regeneration in areas selectively logged.

Conservation Actions

A range wide survey is required to establish A. hunsteinii's current status and to identify important stands for conservation.