Southeastern Asia: Central New Guinea

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The Central Range Sub-Alpine Grasslands [AA1002] are a unique example of alpine shrublands surrounding the highest peaks (up to 4,884 m) in Australasia. These fragile environments are fairly well protected by a combination of formal protection and remoteness.

  • Scientific Code
  • Ecoregion Category
  • Size
    6,000 square miles
  • Status
    Relatively Stable/Intact
  • Habitats

Location and General Description
This ecoregion is made up of scattered alpine meadow habitats above 3,000 m along the Central Cordillera in Irian Jaya, Indonesia and PNG. The Central Cordillera is composed of a series of mountain ranges, which are broadly grouped into the Snow Mountains in Irian Jaya, the Star Mountains in Irian Jaya and PNG, and the Central and Eastern Highlands PNG. Although most of New Guinea has a tropical wet climate, in the case of this ecoregion it is modified by extreme altitude (National Geographic Society 1999). Another classification system puts this ecoregion in a humid upper montane climate (Bleeker 1983). The surface geology of the Central Cordillera is composed of metamorphic and intrusive igneous rocks (Bleeker 1983), along with some sedimentary formations.

The vegetation of the ecoregion consists of alpine meadow, montane, and upper montane tropical evergreen forest (MacKinnon 1997). Vegetation in the Central Ranges varies with elevation, local climate, aspect, and substrate. Upper montane forest consists of conifers (Podocarpus, Dacrycarpus, Dacridium, Papuacedrus, Araucaria, and Libocedrus) and Myrtacae, with a thin canopy and prominent understory (Davis et al. 1995). Above the montane forest, at approximately 3,000 m, the vegetation abruptly changes, and the high plateau areas of the cordillera are interspersed with tree fern (Cyathea) savannas, bogs, and grasslands. Immediately below the alpine zone, the vegetation typically is low shrubs and Deschampsia tussock grasslands (Petocz 1989). Heaths of Rhododendron, Vaccinium, Coprosma, Rapanea, and Saurauia form the limit of sub-alpine forest (Petocz 1989). The alpine habitat above 4,000 m consists of compact herbs such as Ranuculus, Potentilla, Gentiana, and Epilobium, the grasses Poa and Deschampsia, and bryophytes and lichens (Petocz 1989). Rosette and cushion herbs, mosses, lichens, and low ferns become progressively more abundant with altitude and replace grasses above 4,300 m (Miller et al. 1994). The highest areas are capped by snow and ice fields (Petocz 1989).

Biodiversity Features
With the exception of plant endemism, overall richness and endemism of this ecoregion are low when compared with those of other ecoregions in Indo-Malaysia.

This extreme environment is inhabited by only nine mammals, consisting of four murid rodents, two microchiropteran bats, and three marsupials: a tree kangaroo, a cuscus, and an antechinus. Of these mammals, four are endemic or near endemic (Flannery 1995) (table 1). The western shrew mouse (Pseudohydromys occidentalis) and Doria's tree-kangaroo (Dendrolagus dorianus) are considered vulnerable (IUCN 2000).

Table 1. Endemic and Near-Endemic Mammal Species.

Family Species
Dasyuridae Antechinus wilhelmina
Muridae Pseudohydromys occidentalis*
Muridae Stenomys richardsoni*
Muridae Mallomys gunung*

An asterisk signifies that the species' range is limited to this ecoregion.

Eighty-four bird species inhabit this ecoregion, of which an amazing twenty-eight species are endemic or near endemic (Beehler et al. 1986; Coates 1985) (table 2). The Central Range Sub-Alpine Grasslands [AA1002] constitute the upper elevations of the Central Papuan Mountains EBA, which it shares with the Central Range montane rain forest ecoregion. Although the entire EBA contains fifty-four restricted-range species, only twenty-four of these range into the sub-alpine grasslands. The long-bearded honeyeater (Melidectes princeps), MacGregor's bird-of-paradise (Macgregoria pulchra), the ribbon-tailed astrapia (Astrapia mayeri) are considered vulnerable (IUCN 2000; Stattersfield et al. 1998).

Table 2. Endemic and Near-Endemic Bird Species.

Family Common Name Species
Phasianidae Snow Mountain quail Anurophasis monorthonyx*
Psittacidae Painted tiger-parrot Psittacella picta
Aegothelidae Archbold's owlet-nightjar Aegotheles archboldi
Motacillidae Alpine pipit Anthus gutturalis
Acanthizidae Papuan thornbill Acanthiza murina
Eopsaltriidae   Greater ground-robin
Amalocichla sclateriana    
Eopsaltriidae Snow Mountain robin Petroica archboldi*
Eopsaltriidae Alpine robin Petroica bivittata
Cinclosomatidae Blue-capped ifrita Ifrita kowaldi
Pachycephalida Black sittella Daphoenositta miranda
Pachycephalida Lorentz's whistler Pachycephala lorentzi
Meliphagidae   Orange-cheeked honeyeater
Oreornis chrysogenys    
Meliphagidae Short-bearded honeyeater Melidectes nouhuysi*
Meliphagidae Long-bearded honeyeater Melidectes princeps*
Meliphagidae Huon wattled honeyeater Melidectes foersteri
Meliphagidae Spangled honeyeater Melipotes ater
Meliphagidae Sooty honeyeater Melidectes fuscus
Meliphagidae Belford's honeyeater Melidectes belfordi
Meliphagidae Rufous-backed honeyeater Ptiloprora guisei
Meliphagidae Black-backed honeyeater Ptiloprora perstriata
Estrildidae Mountain firetail Oreostruthus fuliginosus
Paradisaeidae Crested bird-of-paradise Cnemophilus macgregorii
Paradisaeidae MacGregor's bird-of-paradise Macgregoria pulchra
Paradisaeidae   Brown sicklebill
Epimachus meyeri    
Paradisaeidae Princess Stephanie's astrapia Astrapia stephaniae
Paradisaeidae Splendid astrapia Astrapia splendidissima
Paradisaeidae   Ribbon-tailed astrapia
Astrapia mayeri    
Paradisaeidae Huon astrapia Astrapia rothschildi

An asterisk signifies that the species' range is limited to this ecoregion.

Five Centres of Plant Diversity are shared between this ecoregion and the adjacent Central Range montane rain forests ecoregion. The Star Mountains-Telefomin-Tifalmin-Strickland Gorge CPD in PNG contains very rich (more than 3,000 vascular plant species) montane and high-altitude vegetation. Alpine communities are found on the summit of Mt. Giluwe, in the Mt. Giluwe-Tari Gap-Doma Peaks CPD. The poorly known Kubor Ranges in PNG contain extensive areas of high-altitude vegetation, and many endemics are likely to exist on the limestone and volcanic ash. The Bismarck Falls-Mt. Wilhelm-Mt. Otto-Schrader Range-Mt. Hellwig-Gahavisuka CPD has a wide variety of vegetation types and contains more than 5,000 vascular plant species. There are numerous endemics already known from the sub-alpine and alpine areas of Mt. Wilhelm, the highest point in PNG (Davis et al. 1995).

Current Status
The eleven protected areas that extend into this small ecoregion cover 7,290 km2, representing more than 47 percent of the ecoregion area (table 3). A gap analysis, based on detailed vegetation and habitat type mapping, has never been performed to determine whether the existing protected area network adequately covers all habitats with protected areas that are large enough to maintain all critical ecological processes.

Table 3. WCMC (1997) Protected Areas That Overlap with the Ecoregion.

Protected Area Area (km2) IUCN Category
Pegunungan Weyland [AA0128], [AA0105] 300 PRO
Gunung Lorentz [AA0105], 127, 128, 129] 3,190 I
Gunung Lorentz Addition 250 PRO
Gunung Lorentz Addition 130 PRO
Mt. Capella [AA0105] 600 ?
Jayawijaya extension [AA0105] 1,130 PRO
Mt. Wilhelm [AA0105] 260 ?
Mt. Onuare [AA0105] 350 ?
Finisterre [AA0107] 310 ?
Mt. Bangeta [AA0107] 410 ?
Mts. Albert Edward/Victoria [AA0120] 360 ?
Total 7,290  

Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.

Types and Severity of Threats
Mining exploration and access afforded by mining operations have become significant sources of threats to this sensitive alpine habitat. Visitation has also increased the level of pollution and litter in the area (Petocz 1989).

Justification of Ecoregion Delineation
Using Whitmore's (1984) map of the vegetation of Malesia and MacKinnon's (1997) reconstruction of the original vegetation, we delineated the large areas of distinct habitat types as ecoregions. The montane evergreen moist forests along the Central Cordillera, including the Snow Mountains, Star Mountains, Central Highlands, and Eastern Highlands, were placed in the Central Range Montane Rain Forests [AA0105]. This ecoregion roughly corresponds to MacKinnon's subunits P3g, P3h, and P3i. The moist forests in the southeastern peninsula were distinguished as the Southeastern Papuan Rain Forests [AA0120]. This ecoregion consists mostly of montane forests but also includes some lowland forests along the coasts and is roughly equivalent to MacKinnon's (1997) biounit P3n. We used the 1,000-m contour from a DEM (USGS 1996) to define the montane-lowland transition. All along the Central Cordillera and in the Huon Peninsula, we separated the alpine habitat into a distinct (Central Range Sub-Alpine Grasslands [AA1002]) ecoregion. Udvardy (1975) placed these ecoregions in the Papuan biogeographic province of the Oceanian Realm.

References for this ecoregion are currently consolidated in one document for the entire Indo-Pacific realm.
Indo-Pacific Reference List

Prepared by: John Morrison
Reviewed by:
This text was originally published in the book Terrestrial ecoregions of the Indo-Pacific: a conservation assessment from Island Press. This assessment offers an in-depth analysis of the biodiversity and conservation status of the Indo-Pacific's ecoregions.