The Biak–Numfoor rain forests is a
tropical moist forest ecoregion
An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...
in
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...
. The ecoregion covers the islands of
Biak
Biak is the main island of Biak Archipelago located in Cenderawasih Bay near the northern coast of Papua (province), Papua, an Indonesian province, and is just northwest of New Guinea. Biak has many atolls, reefs, and corals.
The largest popula ...
,
Supiori,
Numfoor, and several smaller islands, which lie in
Cenderawasih Bay north of
Yapen
Yapen (also Japen, Jobi) is an island of Papua (province), Papua, Indonesia. The Yapen Strait separates Yapen and the Biak Islands to the north. It is in Cenderawasih Bay off the north-western coast of the island of New Guinea. To the west is ...
and
New Guinea
New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...
.
Geography
Biak
Biak is the main island of Biak Archipelago located in Cenderawasih Bay near the northern coast of Papua (province), Papua, an Indonesian province, and is just northwest of New Guinea. Biak has many atolls, reefs, and corals.
The largest popula ...
and
Supiori are the largest islands in the ecoregion. They lie very close together, separated by a narrow and shallow channel.
Numfoor lies southwest of Supiori and Biak. The
Padaido Islands are a group of small islands south and southeast of Biak.
[
The surface geology of Biak and Supiori consists mainly of rugged coralline limestone, with outcrops of schist overlain by basaltic lavas and tuffs. The highest elevations in the ecoregion are on Supiori, where a ridge of mountains parallel to Supiori's southern coast reaches in elevation.
The islands are oceanic, and not part of the New Guinea continental shelf. Their physical isolation from New Guinea meant that plants and animals had to cross the ocean to get to the islands, giving rise to a unique flora and fauna that includes several ]endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
species.
Politically the islands fall into two regencies. Biak Numfor Regency
Biak Numfor Regency is one of the Regencies of Indonesia, regencies (''kabupaten'') in Papua (province), Papua Province of Western New Guinea in northeastern Indonesia.
Geography
The regency consists two of the three largest members of the Schout ...
includes the islands of Biak and Numfor and the Padaido Islands. Supiori Regency covers Supiori, and was split from Biak Numfor in 2004 to become a separate regency.
Climate
The ecoregion has a tropical rain forest climate.[
]
Flora
The original vegetation was tropical wet evergreen forest. The forests are similar in structure and species composition
Relative species abundance is a component of biodiversity and is a measure of how common or rare a species is relative to other species in a defined location or community.Hubbell, S. P. 2001. ''The unified neutral theory of biodiversity and biogeog ...
to the lowland rain forests of mainland New Guinea. Forests consisted of two types, alluvial forests in flatlands and river valleys, and hill forest on the hillsides.[
The tree canopy of the alluvial forest is irregular and multi-tiered, with many emergent trees rising above the canopy. The forests have a shrub and herb layer in the understory with a variety of palms, climbers, ]epiphytes
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...
, and ferns. The tree canopy of the hill forests is lower and more closed than the alluvial forests. The understory has a more open shrub layer and a denser herbaceous layer, with fewer palms.[
Dominant emergent trees on the islands include '' Pometia pinnata'' and species of '']Ficus
''Ficus'' ( or ) is a genus of about 850 species of woody trees, shrubs, vines, epiphytes and hemiepiphytes in the family (biology), family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few spe ...
, Alstonia'', and ''Terminalia
Terminalia may refer to:
* Terminalia (festival)
Terminalia () was an ancient Roman festival in honour of the god Terminus, who presided over boundaries. His statue was merely a stone or post stuck in the ground to distinguish between propert ...
''. Canopy trees include species of ''Garcinia
''Garcinia'' is a genus of flowering plants in the family (biology), family Clusiaceae native to the Sundaland bioregion of Asia, America, Australia, tropical and southern Africa, and Polynesia.
The number of species is disputed; Plants of the W ...
, Diospyros
''Diospyros'' is a genus of over 700 species of deciduous and evergreen trees and shrubs. The majority are native to the tropics, with only a few species extending into temperate regions. Individual species valued for their hard, heavy, dark timb ...
, Myristica, Maniltoa'', and ''Microcos
''Microcos'' is a genus of flowering plants in the family Malvaceae ''sensu lato'' or Tiliaceae or Sparrmanniaceae.
Species
''Plants of the World Online'' lists:
* '' Microcos africana'' (Hook.f.) Burret
* '' Microcos antidesmifolia'' (King) Bu ...
''. Large coastal stands of '' Calophyllum'' are found in northern Biak.[
The recently discovered endemic palm '' Manjekia maturbongsii'' is found in lowland forests, between 80 and 170 meters elevation, on thin soils over limestone.
]
Fauna
The ecoregion is home to 29 mammal species. Five species are endemic to the ecoregion – the Biak glider (''Petaurus biacensis''), Blue-eyed spotted cuscus (''Spilocuscus wilsoni''), Biak naked-backed fruit bat (''Dobsonia emersa''), Biak giant rat (''Uromys boeadii''), and Emma's giant rat (''Uromys emmae''). Biak and Supiori are home to endemic subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
of the common spiny bandicoot, ''Echymipera kalubu philipi''. The Japen rat (''Rattus jobiensis'') is near-endemic, and is also found on Yapen.[Wikramanayake, Eric; Eric Dinerstein; Colby J. Loucks; et al. (2002). ''Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment.'' Washington, DC: Island Press.]["Geelvink Islands". Birdlife International. Accessed 9 July 2021]
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The Biak white-lipped python (''Leiopython biakensis'') is endemic to Biak. The frog '' Oreophryne kapisa'' is endemic to Biak and Supiori.[
Endemic butterflies include the Biak tiger (''Parantica marcia''), Biak threespot crow (''Euploea tripunctata''), and '' Damias biakensis''.
]
Conservation and threats
In 2000, 97% of Biak Numfor Regency, which includes Biak, Numfor, and the Padaido Islands, had tree cover. 158,000 hectares, or 70% of its land area, was primary forest, and the rest was secondary forest
A secondary forest (or second-growth forest) is a forest or woodland area which has regenerated through largely natural processes after human-caused Disturbance (ecology), disturbances, such as Logging, timber harvest or agriculture clearing, or ...
or tree plantations.["Biak Numfor, Papua, Indonesia Deforestation Rates & Statistics". ''Global Forest Watch''. Accessed 16 July 2021. https://www.globalforestwatch.org/dashboards/country/IDN/23/2/] In 2000 98% of Supiori had tree cover with 58,500 ha, or 87% of its land area, covered in primary forest.["Supiori, Papua, Indonesia Deforestation Rates & Statistics". ''Global Forest Watch''. Accessed 16 July 2021. https://www.globalforestwatch.org/dashboards/country/IDN/23/25/]
From 2001 to 2020, Biak Numfor Regency lost 15,400 ha of tree cover, a 7.1% decrease in tree cover since 2000. 3,960 ha, or 27%, was humid primary forest, a 2.5% decrease since 2000.[ From 2001 to 2020 Supiori lost 1,300 ha of tree cover, about a 2% loss since 2000. About half of the tree cover lost (572 ha) was primary forest.][
]
Protected areas
20.86% of the ecoregion is in protected areas.[ Protected areas include Biak Utara Nature Reserve (61.38 km2) on Biak, and Pulau Supiori Nature Reserve (419.9 km2) on Supiori."Pulau Supiori". ''Protected Planet''. Accessed 11 July 2021]
/ref>
External links
*
Geelvink Islands endemic bird area (Birdlife International)
Biak–Numfoor rain forests (DOPA Explorer)
References
{{DEFAULTSORT:Biak-Numfoor rain forests
Australasian ecoregions
Ecoregions of Indonesia
Tropical and subtropical moist broadleaf forests
Schouten Islands