Botanical Name: Agathis macrophylla
Species: A. macrophylla
Common Names: Dakua, Pacific kauri
Habitat: Agathis macrophylla is native to the islands of the southwestern Pacific Ocean in tropical humid lowlands and lower montane regions, notably in Fiji, Vanuatu, the Santa Cruz Islands, and the Solomon Islands. The Pacific kauri is one of the largest and fastest growing species in its genus, and is important in forestry.
Agathis macrophylla is a large evergreen coniferous tree, reaching 40 m in height and 3 m in diameter. It possesses the mottled, shedding bark that is characteristic of other kauri species. Young trees are narrow and conic in shape, but begin to grow a wider, deeper canopy after attaining a trunk diameter of 30–50 cm. In mature specimens, the trunk is generally straight or slightly tapered and clear for 15–20 m before branching into a spreading canopy up to 35 m in diameter. The root system is deep and strong, and the trees are highly wind resistant.
The leaves are green and glossy, elliptical to lanceolate, 7–15 cm long and 2–4 cm wide. They are borne on short petioles and held in a decussate pairs, but twisted so they lie in one plane. Leaves in the shade, of juvenile trees, and of individuals growing in wetter regions, tend to be larger.
Male cones of A. macrophylla are elliptical and measure roughly 2–5 cm long at pollen shed. The short pollen cones help distinguish this species from related Agathis species. Female (seed) cones are globular, 8–13 cm across, and are borne on short woody stalks. The majority of the cone crop matures early to mid February, as the cones turn brown and release the winged seeds, which are small, flattened, and attached to a wing about 3.5 cm in length. Wind dispersal is very efficient; seeds have been known to travel tens of kilometres in the wind, and may even travel hundreds of kilometres during the tropical cyclones that occur frequently in the species’ range.
A plant of the moister lowland tropics and subtropics, growing in areas where the rainfall is evenly distributed throughout the year and is in the range of 1,900 – 6,000 mm. The mean annual temperature is in the range 25 – 28°c Most commonly found on well structured, friable, and freely drained soils. Prefers a position in full sun or light shade, it can also tolerate quite considerable shade, though growth will be greatly reduced. Young plants require sheltered, shady positions. The tree generally prefers basalt-derived clay loams and clays with a well developed upper humus layer. It has also been reported on coral limestone terraces and bordering mangrove vegetation. Tree growth is poor on compacted and waterlogged soils. Plants can withstand strong winds. Grows well in acid soils, tolerating a pH in the range 4.0 – 7.4. A long lived tree that can live for up to 1,000 years. It is fairly fast-growing tree, in favourable conditions, annual growth can reach about 1 – 1.5 metres. Young specimens have a vigorous taproot, whilst mature specimens have wide, spreading root systems that help stabilize soils on ridges and slopes. Trees start producing flowers when about 10 years old, the seed taking two years to mature. The use of selected, superior seed provenances (notably from Vanuatu) and good silviculture will enable the commercial production of timber and veneer in plantations on a 40 – 55-year rotation period. For introduction into areas outside of its natural range, it is important to inoculate seedlings with appropriate mycorrhizal fungi. From a plantation viewpoint, this species stands apart from most other members of the genus because of its ability to grow moderately fast and establish in open, sunny sites
Agroforestry Uses: Tropical cyclones occur at periodic intervals in all parts of its range. Pacific kauri has an ability to withstand strong winds thereby acting as a wind break or barrier. In certain situations it is suited as boundary marker, due to size and longevity. The species is suitable for soil protection and binding in areas where long term stabilization of less stable soil profiles is needed. It has spreading root systems that help stabilize soils on ridges and slopes. The tree is mainly suitable as a long term top storey tree for more shade tolerant understory crops; however, wide-spaced plantings of less dense forms may provide light shade for a wider variety of crops. Other Uses A resin, called ‘resin of Fiji’, is obtained from the trunk. The resin, produced from the living inner bark, was an important component of many varnishes and is still used mixed with synthetics. Commercial export of the resin was formerly practiced in Fiji but was prohibited in 1941, as no method could be found for tapping an economic yield of gum without endangering the life of the tree. The resin is traditionally used as canoe caulk, and the resin soot was used for tattoos. The resin has also been used for glazing pots. The resin has also been used for lighting and torches. Smoke residues of the burnt resin were traditionally used as a dye for the hair. The heartwood is pale cream to gold brown; the sapwood straw yellow to pale brown. The wood is finely grained, lustrous, uniform and easily worked. Damage from pinhole borers may occur in standing trees, while drywood termites and Anobium borers may cause damage in service. The wood is readily kiln dried with a medium shrinkage value. In service the timber is very stable. It is suitable for a wide range of end-uses including laboratory bench tops, vats, sauna baths, battery separators, weatherboards, bowls, novelties, handles, furniture, veneer, and boat building. It has good peeling and gluing properties and is highly sought after for surface veneer. Its finely grained, pale, easily worked, and uniform timber is of major commercial importance with various high value end-uses, including furniture, handicrafts, veneer, boat building, light construction, and panelling.
A. macrophylla is a valued commercial timber species, and its wood is much sought after for many uses. The wood is a cream to gold colour (mature heartwood is a lustrous brown) and much appreciated in the timber industry, particularly as a surface veneer. The dry wood has a density of approximately 540 kg/m³.
Pacific kauri is a valuable tree throughout the southeastern Pacific (Melanesia). The timber is frequently used for house construction, canoe carving, and totem pole construction. Smoke from the resin is used as a black dye for hair, clothes and tattoos, and the leaves are used in traditional medicine.
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