Araucariaceae past, present and living in New Caledonia
If you are a citizen of the northern hemisphere, when you think of conifers you likely picture the pines, firs, spruce and junipers. And likely you also tend to associate the tropics with broadleaved hardwoods and tropical islands with palms and flowering shrubs. Nevertheless, conifers are found in the tropics of the southern hemisphere, especially trees from the Araucariaceae family. These are the descendants of a quite ancient lineage of conifers that once had nearly worldwide distribution.
Conifers are cone-bearing, woody seed plants of the Pinophyta family. They belong to an ancient group called gymnosperms, which appeared roughly 360 million years ago – well before flowering plants (angiosperms). The earliest known conifers date from the late Carboniferous period, around 300 million years ago, the time of the great coal age swamp forests. The fossil record indicates that these early conifers grew in the uplands surrounding the swamps and their foliage is reminiscent of some of today’s araucarians, like that of the Norfolk Island pine (Araucaria heterophylla).
During the Permian period, as the conditions become drier, the tree-sized horsetails and club mosses give way to dry-ground forests dominated, in part, by conifers. After the catastrophic Permian extinctions, through the Mesozoic age of the reptiles and into the Triassic period, conifers continue to diversify. By the late Triassic, (roughly 225 million years ago) trees grew that some believe belong to conifer families extant today: Araucariaceae, Cupressaceae, and Podocarpaceae, as well as a precursors to Pinaceae (group that includes pines). However, fossil evidence from the following period is more conclusive, and these families can be said to have been part of the Jurassic flora.
Trees in the Dinosaur Garden
When artists depict dinosaurs or creatures of the reptile age–in paintings, dioramas and film–they often place them among trees with distinctly araucarian features. This is because of the araucarian-like fossils that date from the Mesozoic and also because the heyday of the dinosaurs coincides with the araucarians: Araucariaceae achieved its maximum diversity in the Jurassic and early Cretaceous periods, when it was distributed almost worldwide. When, at the end of the Cretaceous, dinosaurs became extinct, so did Araucariaceae in the northern hemisphere. Today, araucaria forests are limited to the Southern Hemisphere and are considered a counterpart to the pine and spruce forests of the North.
Araucarians you may know
You may not realize it, but there ia a good chance that you have encountered an Araucarian, even if you do not live in a place where they grow naturally. You may have met one in the guise of a houseplant that originally hails from New Caledonia. However, thanks to a mix-up in seed source long ago, you will know this plant as the Norfolk Island pine (Araucaria heterophylla) rather than the Cook pine (Araucaria columnaris). Cook pines were brought to Hawaii, probably in the nineteenth century, where they have done very well for themselves by naturalizing to their new habitat. They are a common sight in Hawaii, which is the top supplier of Cook pine, rather than New Caledonia. When you go to your local nursery or home improvement store and see a potted Norfolk Island pine, be assured that it is a Cook pine.
In the United States, in Northern California, Oregon, Washington and into British Columbia, the monkey puzzle tree can be seen growing in yards as a landscape plant. The monkey puzzle (Araucaria araucana) is actually a native of Chile and Argentina’s Andean slopes. This species demonstrates a number of features that are common to Araucarians: it grows very tall (up to 100 ft) and looks quite different in its youth than at full maturity. Below: On the left is a yard in the United Kingdom with two young monkey puzzle trees; on the right are fully mature trees in Chile’s Conguillío National Park.
Araucarians of New Caledonia
The abundance of conifers belonging to the ancient plant family Araucariaceae is perhaps New Caledonia’s most striking floristic feature. Out of 41 species in the family Araucariaceae, eighteen are endemic to New Caledonia. In the genus Araucaria alone, thirteen of the nineteen known species are endemic to New Caledonian, where they occur from sea level to 3,000 feet elevation. The collection at the Atlanta Botanical Garden is especially rich in tropical conifers and includes all but two species of New Caledonia’s Araucaria. These trees are in many cases imperiled, so their IUCN ( International Union for Conservation of Nature and Natural Resources) conservation status is listed with each entry.
BERNIER COLUMNAR ARAUCARIA (Araucaria bernieri) The bernier columnar araucaria grows most commonly in the lowland rainforests of southern New Caledonia, but some outlying stands can be found in the north. The difference is that the northern bernier columnar araucarias grow in serpentine (ultramafic) soils and are severely dwarfed; they top out at less than 15 feet. Their southern counterparts are rainforest giants that can grow to 160 feet tall. Conservation status: Vulnerable
PIGGYBACK ARAUCARIA (Araucaria biramulata) This Araucaria species gets its name, which is Latin for “twice-branched,’ from its unusual growth habit. A. biramulata grows secondary branches near its trunk, as if piggyback to the primary branches. It can be found mainly inland, in rocky terrain. Conservation status: Vulnerable
COOK PINE, COLUMNAR PINE (Araucaria columnaris) If you guessed that “Cook” refers to explorer Captain James Cook, you are correct. On September 4, 1774 Captain Cook and the crew of the HMS Resolution became the first Europeans to visit New Caledonia. Approaching the main island, they saw “a vast cluster of … elevated objects.” The men placed bets as to whether they were trees or large stone pillars. Once ashore, they found trees that resembled pines. Cook regarded such tall, strait trees as a boon to sailors: “Excepting New Zealand, there was not an island known in the South Pacific Ocean, where a ship could supply herself with a mast or yard.” The tree seems to achieve its columnar shape only where it grows in its native habitat, on the coastlines of Southern Grande Terre, the Isle of Pines and Loyalty Islands. There they are battered by winds and tropical storms that knock out some of their limbs.
Traditionally, A. columnaris is a very important tree to the Kanak. It is a powerful symbol of masculinity and of the clan chief. Kanak villages had at their center a large meeting house, in front of which was often an aisle of A. columnaris and coconut palms. With 28 Kanak languages spoken in New Caledonia, the Cook pine has many names. In its natural habitat, the south province of Grande Terre and on the Isle of Pines, the Cook pine is called xéxé. Conservation status: Least concern
MOUNT HUMBOLDT ARAUCARIA (Araucaria humboldtensis) This tree casts a distinctive profile where it grows, along the lower slopes of Mount Humboldt. Its crown is decidedly flat, while the lower half of the tree is sparsely branched. Conservation status: Vulnerable
MOUNT MOU ARAUCARIA (Araucaria laubenfelsii) Named for the mountain in southern New Caledonia where it most commonly grows, the Mount Mou aracauria emerges above the canopy of the mountain rainforest. Conservation status: Near threatened
LUSH ARAUCARIA, COAST ARAUCARIA, SAPIN DE NOËL ARAUCARIA (Araucaria luxurians) Growing on the serpentine cliffs on the southern coast of New Caledonia, the lush araucaria bears some similarity to the Cook pine. As both its common and scientific names suggest, the lush araucaria’s foliage is more luxuriant than the Cook pine. The lush araucaria grows in more of a conical shape, making it the Christmas tree of choice on the islands. Unfortunately, due to its small distribution and small populations, the lush araucaria is particularly vulnerable to the mining activities in its habitat and its numbers have been on the decline.
Conservation status: Endangered
SUMMIT ARAUCARIA (Araucaria montana) Perhaps the most common and widespread of the New Caledonian Araucarias, the summit araucaria grows in the serpentine soils of the inland high plateaus and mountain ridges. Scattered stands are found in the macquis minière shrublands and low cloud forests. Mining activities are a threat, especially to smaller, more isolated populations. Conservation status: Vulnerable
CHANDELIER ARAUCARIA, MUELLER ARAUCARIA (Araucaria muelleri) Found in the Pleine des Lacs region, the chandelier araucaria has the largest leaves of the araucaria species on New Caledonia. It actually ties with the monkey puzzle tree for widest leaves in the genus. This feature, combined with upright branchlets, creates the tree’s chandelier-like appearance. Principal threats to the species are the expansion of mining activities, especially with the construction of a smelter on Goro Plateau, and an increased risk of fire, even in protected areas. Conservation status: Endangered
PORT BOISÉ ARAUCARIA (Araucaria nemorosa) The Port Boisé araucaria is one of the rarest conifers in the world. Its scientific name is Latin for “of the groves,” and indeed these Araucaria are found in dense groves in the vicinity of Port Boisé. Unfortunately A. nemorosa also grows in mineral rich soils, and thus the species is facing extinction thanks to strip mining in its habitat. Conservation status: Critically endangered
RULE ARAUCARIA (Araucaria rulei) Rule araucaria is found in some of the most rugged areas of New Caledonia. The trees grow on rocky slopes and mountain plateaus in ultramafic soil, which is rich in heavy metals and poor in nutrients. A. rulei grows slowly, reaching heights of 65 to 80 feet, far shorter than the araucarias that grow in the island’s humid rainforests. A. rulei is found almost exclusively in the nickel-rich areas on the main island, and as a result has seen its habitat shrink. Over the last 100 years, the A. rulei population has declined by more than 50%, most rapidly in the last decade. This is a direct consequence of open cast mining, which brings roads, erosion, soil dumping and unintentionally-set wildfires. Conservation status: Endangered
MOUNT PANIÉ ARAUCARIA (Araucaria schmidii) Found in the Mount Panié-Colnett range in northeastern New Caledonia, this araucaria species looms over the mountain shrublands and dwarf cloud forests. The Mount Panié araucaria is unusual in that the leaves of juvenile trees are longer than those of mature trees. Conservation status: Vulnerable
CLIFF ARAUCARIA (Araucaria scopulorum) The scientific name of this species is Latin for “of the cliffs,” which is just where this rare Araucaria is found. Rather than the coral-derived soil in which the Cook pine grows, the coastal cliffs to which A. scopulorum cling are serpentine. Conservation status: Endangered
VIEILLARD COLUMNAR ARAUCARIA (Araucaria subulata) Although it is distributed over a large area of southern New Caledonia, individual populations of Vieillard columnar araucaria are small and widely scattered. It prefers mountain cloud forests of the interior and can grow quite tall (160 ft). The wood of the Vieillard columnar araucaria is of excellent quality, so the species is threatened both by logging and mining. Conservation status: Near threatened
Agathis: Kauri of New Caledonia
The forest giants of New Caledonia belong to the genus Agathis, also called kauri trees. Kauri is a Maori word that originally referred to New Zealand’s Agathis australis but now is commonly applied to all species of Agathis. With long, thick trunks, kauri trees are prized for their timber and consequently have been heavily logged. They are also highly resinous, and large deposits of kauri gum form where their branches fork. This gum, which helps the trees heal from injury, was harvested for use in the varnish industry.
RED KAURI, CORBASSON KAURI (Agathis corbassonii) On New Caledonia there is red kauri (Agathis corbassonii) and white kauri (Agathis moorei), so called because of the respective color of their wood. However, some botanists do not think red kauri is distinct from white, so do not recognize A. corabassonii as a separate species. Both red and white kauri grow in rainforests, along ridge tops and slopes where the soil is not derived from serpentine. While red kauri does not grow in mining districts, it is still subject to forest exploitation. Conservation status: Vulnerable
KOGHIS KAURI, SERPENTINE FOREST KAURI (Agathis lanceolata) On the forested slopes of Mt. Koghi grows a giant. The Koghis kauri (Agathis lanceolata) is the largest species of kauri endemic to New Caledonia. Other trees may grow as tall, at 130 feet, but none have the massive girth of the Koghis kauri trunk, which can be 8 feet across. Its bark is typical of trees in the Agathis genus, flaking away and leave behind a pattern that resembles hammer-marks. The species name is Latin for “shaped like a little lance,” which applies to its leaves. Conservation status: Vulnerable
MOUNT PANIÉ KAURI (Agathis montana) Restricted to the summits of the Mount Panié range, the Agathis montana claims the highest range of all the New Caledonia kauris. Thanks to its relatively low stature (50 ft) and the inaccessibility of its habitat, the Mount Panié kauri has escaped the exploitation visited upon its lowland relatives. The species has also received additional protection by the establishment of the Mount Panié Special Botanical Reserve, which includes the summit forest. Conservation status: Near threatened
MOORE’S KAURI, WHITE KAURI (Agathis moorei) Another kauri that rises above the canopy of New Caledonia’s humid rainforests is Agathis moorei. As you might guess, its wood is white in appearance, distinguishing it from the red kauri (Agathis corbassonii) also found on the island. The word Agathis is Greek for ball of string, which refers to the kauri tree’s large round female cones. Once the cones fully mature, they break apart releasing seeds that drift down on wing-like structures. Some Kanak people plant kauri next to Cook pines to indicate the home of a family high rank. The beautiful symmetry of tree’s cone is regarded as emblematic of clan unity under the leadership of the chief. The wood was traditionally used to craft canoes, sculpture, and support beams for houses. Conservation status: Vulnerable
SCRUB KAURI (Agathis ovata) Trees in the genus Agathis are especially well adapted for places like the maquis because they are highly efficient nitrogen users. With the help of mycorrhizae (specialist fungi) they can produce far more wood, bark, and cones than other trees given the same amount of nitrogen. A. ovata also grows in the humid mountain forests, which are more abundant in rain and provide richer soil. In these conditions A. ovata can reach 80 feet. Conservation Status: Endangered
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