portion of mainland Papua New Guinea was once officially named Papua, when overseen by colonial Australia. Finally, political activists call western New Guinea "West Papua"—the name that the local assembly had chosen for the planned independent nation that was to arise in 1962 through a United Nations mandate.
Physiography, Geography, and Geology
Papua is a complex piece of the planet, partly because of its convoluted tectonic history, discussed in some detail in Chapter 2.1. In brief, the Papuan component of the Australian tectonic plate has been rafting northward, building a prodigious central cordillera as well as sweeping up island arcs in the north and northwest. This plate continues to drift northward and northern coastal ranges are presumably still rising.
Mountains define Papuan geography, no doubt. Two east-west ranges dominate—the Central Cordillera (Merauke Range, "Maoke" is a misnomer; this includes a western component, Sudirman Range, and an eastern component, Jayawijaya Range) and the north coastal ranges that extend westward into Cenderawasih Bay as rugged Yapen Island. The Central Cordillera has been created by the compression of the Australian plate with the Pacific plate, with massive uplift over the last several million years. The highest points of the Sudirman and Jayawijaya ranges are oceanic sediments. This cordillera rises to more than 3,000 meters for its entire length in Papua, creating a challenge for Indonesian road builders wishing to link up the northern and southern catchments. The cordilleran watershed dips rather gradually on its northern face and abruptly on the south side. Heavy rainfall striking the southern scarp has deeply dissected this southern face, creating scores of sediment-laden and unstable rivers that dump out onto a rocky alluvial plain in the south that is almost 200 km wide in the east and only 40 km wide in the far west (west of Timika).
The highest peaks of Papua are scattered about the main cordillera. Highest of all is Mt Jayakusuma or Mt Jaya (4,884 m) once known as Mount Carstensz or Carstensz Toppen, dominating the western terminus of the Merauke Range. Nearby Ngga Pilimsit or Mount Idenburg stands at 4,717 m. In central and eastern segments of the cordillera stand Mount Trikora (formerly Mount Wilhelmina) at 4,730 m and Mount Mandala at 4,640 m. Small, rapidly melting glaciers cap Jaya and Pilimsit.
The accreted island arcs in the north can be seen today as isolated coastal ranges: the Cyclops, Foja, and Van Rees Mountains (north of the Tariku and Taritatu [formerly Idenburg] rivers), mountainous Yapen Island, the Wandammen, Arfak (2,940 m), and Tamrau mountains (2,824 m) of the Vogelkop Peninsula, as well as the Raja Ampat Islands west of the Vogelkop. Strange tectonic contacts apparently have also produced the Kumawa and Fakfak mountains south of the Vogelkop on the Bomberai and Onin peninsulas. The Bird’s Neck region, which connects the Vogelkop with the main body of Papua, is karstic, with fjordlands, white sand barrens, and lakes.
Papua is scored by a range of major rivers both north and south, east and west. In the north, the Mamberamo system drains the interior Mamberamo Basin and virtually the entire northern watershed of Papua’s central range. The main channel of the north-flowing Mamberamo cuts between the Foja Mountains (on the east) and Van Rees Mountains (on the west) on its way to the sea. This ramrod straight, swiftly-flowing stream is one of the most remarkable on this great island, even though it is only 150 km in length. At the head of the Mamberamo, the river drains the great interior basin swamplands that are infested by meander belts and oxbow lakes. The Taritatu (formerly Idenburg) River drains the eastern half of the basin and the central mountains to the south, its tributaries reaching to the Papua New Guinea border and nearly to Jayapura. Its western branch, the Tariku (or Rouffaer) River, drains the smaller western side of the basin, and quickly divides into the main flow of the Rouffaer (on the north) and the Van Daalen (to the south). The Van Daalen drains the north slope of the Central Cordillera, and thus is a much more substantial flow.
Papua’s other great rivers drain the ragged southern scarp of the central range in the eastern half of Papua. Among these, the Digul is the greatest, followed by the Catalina, which in the mountains becomes the famous Baliem that drains the Grand Valley of the Baliem, discovered in the late 1930s by explorer-pilot Richard Archbold. Scores of lesser rivers sweep heavy gravels southward toward the muddy Arafura Sea. These turbid and unstable rivers tumble out of the mountains, with torrential flows in the mountain gorges, and heavily braided channels in the flats that spread out from the bottom of the ranges. As one moves westward, one finds river after river, each shorter than the preceding, until the central mountains pinch off the alluvial plain at the bottom of the Bird’s Neck.
LAKES
Papua has a few prominent lakes. Lake Sentani, near the Papuan capital Jayapura, was apparently created by tectonic movement related to the uplift of the coastal Cyclops Mountains just to the north. The lower Mamberamo features Lake Rombebai, the largest lake in Papua, as well as smaller Lake Bira. These are swampy backwater lakes. At the western end of the central cordillera we find the Paniai Lakes in an interior highland basin. Lake Yamur, on the Bird’s Neck, is home to a freshwater shark. Finally, highlands lakes (Anggi Gigi and Anggi Gita) are found in the Arfak Mountains of the Vogelkop.
SWAMPS,MANGROVES, AND SAVANNAS
The vast lakes plain of the Mamberamo Basin is dominated by seasonally inundated swamplands of various types. There are great coastal swamplands along much of the southern coast, from the Casuarina coast in the southeast to the swamplands south of Timika, far to the west. Indonesia’s largest mangrove ecosystem is nestled in the head of Bintuni Bay, which separates the Vogelkop (Bird’s Head) Peninsula from the more southerly Bomberai Peninsula. Elsewhere in Papua, swamps can be found in many alluvial localities where drainage is impeded, around lowland rivers, and in and around Dolok (Yos Sudarso) Island in the far south. In the far southeast, by the Papua New Guinea border, is a swath of savanna that ranges westward to Dolok Island—part of the great Trans-Fly savannas that have the look of Australia rather than New Guinea. This is a highly seasonal low-rainfall zone that toggles from an inundation season to a burning season.
COASTS
Papua’s abundant coastline is not uniform. In the northeast, one finds hilly country reaching the coast, which features a mix of white sand beaches and rocky shorelines. Long stretches of beach dominate in the north, backed by coastal hills. The eastern shore of Cenderawasih (formerly Geelvink) Bay features swamps and mangroves, whereas the western shore is more rugged and hilly. The north side of the Vogelkop is rugged, whereas the south side is low and swampy. Much of the southern and southeastern coastline are low and silty, with dark sand beaches backed by casuarinas, with swamplands further inland. The most spectacular coastlines are found on the south side of the Bird’s Neck, between Arguni Bay and Etna Bay. Here one finds tropical karstic fjordlands that feature coastal mountains rising to more than 1,000 meters, steep cliffs, deep embayments, and scenery galore.
ISLANDS
Papua has more than a thousand fringing islands, from tiny to quite large. The Raja Ampat Islands range off the western coast of the Vogelkop Peninsula, and include Waigeo (3,155 km2), Salawati (1,632 km2), Misool (2,041 km2), Batanta (453 km2), and Kofiau (150 km2), among others. This remarkable archipelago supports the world’s richest coral reefs and considerable endemic forest biodiversity (e.g., Wilson’s Bird of Paradise, Red Bird of Paradise, Waigeo Brush-turkey). The islands of Cenderawasih Bay include two isolated oceanic islands with distinct island faunas (Biak/Supiori, 2,497 km2, and Numfoor, 311 km2), as well as the mountainous land-bridge island of Yapen (2,227 km2). In addition, there are the Padaido Islands southeast of Biak, and Num Island west of Yapen, and a number of small coastal islands in the south and west portions of the Bay. Small islands also dot the north coast and fringe the Fakfak and Triton Bay region. Papua’s largest island is Dolok (11,192 km2), which is a vast mudbank outwash from the silt-laden rivers of the southeast coast. It is often forgotten because of its unpre-possessing nature and isolation, and its minimal distance from the mainland.
Ecological Setting
New
