Agathis robusta

Agathis robusta, commonly known as Dundathu pine, kauri pine, Queensland kauri (pine), Australian kauri (pine) or smooth-barked kauri, is a coniferous tree in the family Araucariaceae. Although sometimes called a pine it is not a true pine, having leaves rather than needles. It has a disjunct distribution, occurring in eastern New Guinea and New Britain in Papua New Guinea and Queensland, Australia.

Description
Agathis robusta is a large evergreen tree with a straight cylindrical trunk, which can often reach a height of 30 –, and occasionally 50 m. The trunk is usually about 1.2 m diameter at breast height (DBH), but occasionally may reach 3 m. The bark is orange-brown to grey-brown, smooth, but shedding in large flakes.

The linear-elliptic leaves are up to 13 cm long and 4 cm wide, with numerous fine parallel veins and no midrib. They are carried on petioles measuring 3 to 10 mm and are arranged in opposite pairs (rarely whorls of three) on the stem.

The globose, green seed cones measure 8 – diameter with up to 440 scales, and mature in 18–20 months after pollination. They disintegrate at maturity to release the seeds. The male (pollen) cones are cylindrical, 5 – long and 9 mm diameter.

Taxonomy
The Queensland kauri was first described as Dammara robusta in 1859 by the German-born Australian botanist Ferdinand von Mueller and published in the journal Quarterly Journal and Transactions of the Pharmaceutical Society of Victoria. In 1883 the Colonial Botanist of Queensland Frederick Manson Bailey published a paper in which he gave the species its current binomial name Agathis robusta.

Subspecies
There are two recognised subspecies, namely:
 * Agathis robusta subsp. nesophila Whitmore (syn. Agathis spathulata de Laub. ), which is restricted to eastern New Guinea and New Britain
 * Agathis robusta ssp. robusta, the autonymous subspecies, which is native to New Guinea and Queensland.

Etymology
The genus name Agathis is from the Ancient Greek word ἀγαθίς 'ball of thread', a reference to the appearance of the female cones (seed cones). The species epithet is derived from the Latin word rōbustus meaning 'robust'.

Distribution and habitat
Agathis robusta occurs in three distinct locations — a southern population in southeast Queensland in the regions around Gympie, Maryborough, and K'gari (Fraser Island); another population in northeast Queensland in the regions from Ingham to Cooktown, including the Atherton Tablelands; and the third in New Guinea. The north Queensland population was formerly recognised as Agathis palmerstonii, but is now considered to be synonymous with the southern grouping.

The species grows in rainforest on well-drained soils of various types, at elevations up to 1100 m and where the annual rainfall is between 1100 and 1500 mm.

Ecology
The cones of the Queensland kauri are eaten by sulphur-crested cockatoos (Cacatua galerita).

Conservation
Agathis robusta is listed by both the Queensland Department of Environment and Science and the IUCN as least concern. However, the IUCN assessment states that the "subspecies in Papua New Guinea has been assessed as Vulnerable" due to ongoing, albeit limited, logging.

Pests and diseases
A number of Lepidoptera species utilise the Queensland kauri as a host plant, including Agathiphaga queenslandensis, Heteropsyche poecilochroma, Leipoxais rufobrunnea, Darna nararia, Orgyia australis, Achaea janata, and Lexias dirtea.

Uses
This tree produces a high quality timber, which was used for a variety of purposes, such as cabinetmaking, joinery, framing, and plywood. This led to it being heavily logged from the mid-19th century, with the result that the large stands of these trees, which were once common, are now gone, although many individual trees may still be found. Logging in north Queensland continued until the establishment of the Wet Tropics of Queensland World Heritage area in 1987.

State-owned plantations of kauri were established in both north and south Queensland in the first half of the 20th century and met with varying degrees of success; however, today little more than 100 ha of plantation kauri exists.