New Guinea Highlands

The New Guinea Highlands, also known as the Central Range or Central Cordillera, are a chain of mountain ranges and intermountain river valleys, many of which support thriving agricultural communities, on the large island of New Guinea, which lies to the north of Australia. The highlands run generally east-west the length of the island, which is divided politically between Indonesia in the west and Papua New Guinea in the east.

Description

The Central Cordillera, some peaks of which are capped with ice, consists of (from east to west): the Central Highlands and Eastern Highlands of Papua New Guinea including the Owen Stanley Range in the southeast, whose highest peak is Mount Victoria at 4,038 meters (13,248 feet), the Albert Victor Mountains, the Sir Arthur Gordon Range, and the Bismarck Range, whose highest peak is Mount Wilhelm at 4,509 meters (14,793 feet), which is an extinct volcano with a crater lake; the Star Mountains on the Papua New Guinea–Indonesia border; and the Maoke Mountains or Snow Range in Indonesia, where perpetual snow was found by H. A. Lorentz in 1909 at 14,635 ft, and whose highest peaks are Puncak Jaya (Mt. Carstensz) at 4,884 m (16,023 feet), Puncak Mandala (Mt. Juliana) at 4,760 meters (15,610 feet) and Puncak Trikora (Mt. Wilhelmina) at 4,750 meters (15,580 feet).

Although some valleys such as the Wahgi Valley in the Western Highlands, Papua New Guinea are heavily cultivated and support urban settlements most of the mountains have traditional tribal village communities in the grassy mountain valleys. The PNG Highland provinces are: Eastern Highlands Province, the most heavily populated area of PNG; Simbu Province (or Chimbu) whose centre is the small coffee-growing town of Kundiawa on the Waghi River near Mount Wilhelm; the Western Highlands; the rugged Enga Province the home of the Enga people with its administration in the very small town of Wabag on the Lai River, and containing the large Porgera Gold Mine; and Southern Highlands Province, with its centre in the small town and airport of Mendi, and containing the Huli wigmen area around the town of Tari. The Highlands Highway connects many of these towns. Larger urban areas in the PNG Highlands include the Western Highlands capital and PNG's 3rd largest city Mount Hagen (near the extinct Mount Hagen (volcano)), the Eastern Highlands capital and former colonial town of Goroka, and the mining town of Tabubil. The climate is humid as you would expect of the tropical rainforested island of New Guinea, but the higher mountain slopes are of course cooler than the lowlands.

The Highlands are the source of a number of important rivers including the Ramu River in the north and the Wahgi River in the south, and lakes including Lake Kutubu, near which oil has been extracted since 1992 by Chevron.

History

The fertile Highlands have long been inhabited but were not settled by the Western powers during the early colonial period. Indeed they were first visited by western zoologists and explorers, such as Mick Leahy, who opened the Waghi Valley and Mount Hagen, and Richard Archbold in the 1930s.

Ecology

The New Guinea Highlands are home to a great variety of Australasian plant and animal communities, distinct from the surrounding lowlands to the north and south of the central ranges and varying up and along the mountain ranges. The habitats of the mountains have been separated into two ecoregions, depending on their elevation, the tropical montane forests and alpine grasslands, but within these broad bands there is a variety of wildlife along the island as some of the mountains stand quite a distance from others with some species existing of plant or animal existing on only one or two mountains. Particular centres of plant diversity are: the Star Mountains area of western Papua New Guinea near the Indonesian border including Telefomin and Strickland Gorge; the Hunstein Range; Mount Giluwe, a major birdwatching area for Birds of Paradise; the volcanic limestone Kubor Range; the Bismarck Range/Mount Wilhelm/Schrader Range/Mount Gahavisuka, of which Mount Wilhelm is particularly rich in endemic species; and finally the Crater Mountain and Mount Michael in the Eastern Highlands.

Central Range montane rain forests

The montane rain forests (from 1000 to 3000m) can be further categorised into three broad vegetation zones on the mountains, distinguished by elevation.^[1] The lower montane forests extend from 1000 to 1500 meters elevation. They are dominated by broadleaf evergreen trees, including Castanopsis acuminatissima, Lithocarpus spp., elaeocarps, and laurels. Coniferous Araucarias may form thick stands. The upper montane forests, which extend from 1500 to 2500 meters elevation, are dominated by moss-covered Nothofagus. Finally, the high mountain forest extends from 2,500 to 3,000 meters elevation. Conifers (Podocarpus, Dacrycarpus, Dacrydium, Papuacedrus, Araucaria, and Libocedrus) and broadleaf trees of the Myrtle family (Myrtaceae) form a thin canopy, with a prominent understory.

The montane forests are home to a rich wildlife, a great deal of which is unique to these mountains including a many of plants, reptiles and over 100 birds and animals. Of the 90 mammals found on the island, 44 are endemic, a very high proportion. The birds and animals include many Australasian species such as Tree-kangaroos, Bowerbirds, Australasian Robins, Honeyeaters, and Birds of Paradise. Four of the endemic mammals are critically endangered: the Bulmer's Fruit Bat, with only tiny communities remaining in the Papua New Guinea end of the island, and three rodents; a large Leptomys, the Eastern Shrew Mouse, and the Lesser Small-toothed Rat. There are 55 bird species endemic to the mountains from a total of 348 birds found here. There are a number of endemic butterflies, particularly on the Weyland Mountains and the Wahgi Valley.

Apart from in the cultivated valleys the montane forests are largely intact, although the logging industry is a constant threat as more and more access to the mountains is achieved by road building. 20% of this ecoregion is contained within protected areas, mostly in the Indonesian half of the island, including the largest protected area in South East Asia, the huge Lorentz National Park in the highlands, a section of which is montane forest ecosystem.

Central Range sub-alpine grasslands

Above 3000 meters elevation, the high mountain forest yields to remote sub-alpine habitats including alpine meadows, conifer forest, tree-fern (Cyathea) grasslands, bogs, and shrubby heaths of Rhododendron, Vaccinium, Coprosma, Rapanea, and Saurauia all quite different from the tropical rain forest that covers most of New Guinea.

The alpine habitat above 4,000 meters consists of compact rosette and cushion herbs, such as Ranunculus, Potentilla, Gentiana, and Epilobium, grasses (Poa and Deschampsia), bryophytes, and lichens.^[2]

While there are a number of endemic plants there are few animals on the higher slopes, with only nine mammals found here: four rodents, two bats, a cuscus possum, an antechinus and Doria's Tree-kangaroo (Dendrolagus dorianus). Four of these are endemic: the small marsupial Black-tailed Antechinus, Western Shrew Mouse, Glacier Rat and Alpine Woolly Rat. There are nearly 100 birds of which 28 are considered endemic or nearly so, including the vulnerable Long-bearded Melidectes (Melidectes princeps), Ribbon-tailed Astrapia (Astrapia mayeri) and Macgregor's Giant Honeyeater, which although endangered generally is a cultural icon of the Ketengban people of the Star Mountains and therefore protected in some areas ^[3].

Almost half of these remote grasslands are protected in national parks and they are in good condition although in recent times more people are accessing the highlands as visitors or through involvement in mining.

References

1. ^ "Central Range Montane rain forests", WWF scientific report. Accessed May 25 2008 [1]
2. ^ "Central Range sub-alpine grasslands", WWF scientific report. Accessed May 25 2008 [2].
3. ^ http://www.arkive.org/macgregors-bird-of-paradise/macgregoria-pulchra/info.html^{[dead link]}

See also

• List of highest mountains of New Guinea

External links

• Central Range montane rain forests (World Wildlife Fund)
• Central Range sub-alpine grasslands (World Wildlife Fund)