Agathis macrophylla
Encyclopedia
Agathis macrophylla known as the Pacific Kauri, is a coniferous
tree 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
throughout the humid tropics.
It is a large evergreen
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 petiole
s 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 wood
y 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 cyclone
s that occur frequently in the species' range.
A. macrophylla is one of the largest trees in its range, and occurs as a dominant emergent tree in closed, humid, lowland-montane tropical forests. Associated plant species vary from location to location, but include Cryptocarya turbinata, Ilex vitiensis, Garcinia vitiensis, Palaquium spp., and Podocarpus
spp. in Vanuatu, Calophyllum vitiense, Dacrydium nidulum
, Retrophyllum vitiense
, Fagraea berteroana, and Podocarpus
spp. in Fiji.
It is one of the fastest growing species in its genus, capable of growing 1-1.5 metres in height annually in lightly shaded to open areas, where growth is fastest. The species is fairly shade tolerant, especially in the seedling stage, though growth is slow under suppression. Strong root systems enable mature trees to withstand cyclones and seed rapidly into gaps. The species on the whole is long lived, capable of reaching ages of 300-1000 years.
. 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.
Pinophyta
The conifers, division Pinophyta, also known as division Coniferophyta or Coniferae, are one of 13 or 14 division level taxa within the Kingdom Plantae. Pinophytes are gymnosperms. They are cone-bearing seed plants with vascular tissue; all extant conifers are woody plants, the great majority being...
tree native to the islands of the southwestern Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
in tropical humid lowlands and lower montane regions, notably in Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...
, Vanuatu
Vanuatu
Vanuatu , officially the Republic of Vanuatu , is an island nation located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is some east of northern Australia, northeast of New Caledonia, west of Fiji, and southeast of the Solomon Islands, near New Guinea.Vanuatu was...
, the Santa Cruz Islands
Santa Cruz Islands
The Santa Cruz Islands are a group of islands in the Pacific Ocean, part of Temotu Province of the Solomon Islands. They lie approximately 250 miles to the southeast of the Solomon Islands Chain...
, and the Solomon Islands
Solomon Islands
Solomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal...
. The Pacific Kauri is one of the largest and fastest growing species in its genus, and is important in forestry
Forestry
Forestry is the interdisciplinary profession embracing the science, art, and craft of creating, managing, using, and conserving forests and associated resources in a sustainable manner to meet desired goals, needs, and values for human benefit. Forestry is practiced in plantations and natural stands...
throughout the humid tropics.
Description
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
, reaching 40 m in height and 3 m in diameter. It possesses the mottled, shedding bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
that is characteristic of other kauri
Agathis
The genus Agathis, commonly known as kauri or dammar, is a relatively small genus of 21 species of evergreen tree. The genus is part of the ancient Araucariaceae family of conifers, a group once widespread during the Jurassic period, but now largely restricted to the Southern Hemisphere except for...
species. Young trees are narrow and conic in shape, but begin to grow a wider, deeper canopy
Canopy (forest)
In biology, the canopy is the aboveground portion of a plant community or crop, formed by plant crowns.For forests, canopy also refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms .Sometimes the term canopy is used to refer to the extent...
after attaining a trunk diameter of 30-50 cm. In mature specimens, the trunk
Trunk (botany)
In botany, trunk refers to the main wooden axis of a tree that supports the branches and is supported by and directly attached to the roots. The trunk is covered by the bark, which is an important diagnostic feature in tree identification, and which often differs markedly from the bottom of the...
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
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
system is deep and strong, and the trees are highly wind resistant.
The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are green and glossy, elliptical to lanceolate
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
, 7-15 cm long and 2-4 cm wide. They are borne on short petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
s 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
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...
of A. macrophylla are elliptical and measure roughly 2-5 cm long at pollen shed
Anthesis
Anthesis is the period during which a flower is fully open and functional. It may also refer to the onset of that period.The onset of anthesis is spectacular in some species. In Banksia species, for example, anthesis involves the extension of the style far beyond the upper perianth parts...
. 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 wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
y stalks. The majority of the cone crop matures early to mid February, as the cones turn brown and release the winged seeds
SEEDS
SEEDS is a voluntary organisation registered under the Societies Act of India....
, 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 cyclone
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
s that occur frequently in the species' range.
Ecology
Podocarpus
Podocarpus is a genus of conifers, the most numerous and widely distributed of the podocarp family Podocarpaceae. The 105 species of Podocarpus are evergreen shrubs or trees from 1-25 m in height...
spp. in Vanuatu, Calophyllum vitiense, Dacrydium nidulum
Dacrydium nidulum
Dacrydium nidulum is a species of conifer in the Podocarpaceae family.It is found in Fiji, Indonesia, and Papua New Guinea.Grows in moist locations, tree to 26m.-References:* Conifer Specialist Group 1998. . Downloaded on 10 July 2007....
, Retrophyllum vitiense
Retrophyllum vitiense
Retrophyllum vitiense is a species of conifer in the Podocarpaceae family.It is found in Fiji, Indonesia, Papua New Guinea, and Solomon Islands.-References:* Conifer Specialist Group 1998. . Downloaded on 10 July 2007....
, Fagraea berteroana, and Podocarpus
Podocarpus
Podocarpus is a genus of conifers, the most numerous and widely distributed of the podocarp family Podocarpaceae. The 105 species of Podocarpus are evergreen shrubs or trees from 1-25 m in height...
spp. in Fiji.
It is one of the fastest growing species in its genus, capable of growing 1-1.5 metres in height annually in lightly shaded to open areas, where growth is fastest. The species is fairly shade tolerant, especially in the seedling stage, though growth is slow under suppression. Strong root systems enable mature trees to withstand cyclones and seed rapidly into gaps. The species on the whole is long lived, capable of reaching ages of 300-1000 years.
Uses
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 veneerWood veneer
In woodworking, veneer refers to thin slices of wood, usually thinner than 3 mm , that are typically glued onto core panels to produce flat panels such as doors, tops and panels for cabinets, parquet floors and parts of furniture. They are also used in marquetry...
. 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
Canoe
A canoe or Canadian canoe is a small narrow boat, typically human-powered, though it may also be powered by sails or small electric or gas motors. Canoes are usually pointed at both bow and stern and are normally open on top, but can be decked over A canoe (North American English) or Canadian...
carving, and totem pole
Totem pole
Totem poles are monumental sculptures carved from large trees, mostly Western Red Cedar, by cultures of the indigenous peoples of the Pacific Northwest Coast of North America...
construction. Smoke from the resin is used as a black dye for hair, clothes and tattoos, and the leaves are used in traditional medicine.
External links
- Agathis macrophylla at the Gymnosperm Database.