Perhaps the most biologically rich and culturally diverse region of the planet, the tropical Indo-Pacific is composed of a vast array of tens of thousands of islands, stretching from Indonesia eastward to Polynesia and northward to Micronesia. At its center is the Melanesian island of New Guinea, the world’s largest and highest tropical island. Various activities such as logging, forest conversion for agriculture, introduced exotic species, and overexploitation of resources present a serious and increasing threat to the Indo-Pacific’s rich trove of biological and cultural diversity.

Learn more about . . .

• Biodiversity in the Indo-Pacific
• New Guinea Biodiversity

Biodiversity in the Indo-Pacific

The unparalleled richness of Indo-Pacific is due to its geographic position at the crossroads of Asia and the Pacific. This is a geologically complex region – the so-called “Pacific Ring of Fire” – that has resulted in an array of biologically and culturally unique island ecosystems and species. In the far western Pacific (Sumatra, Java, Borneo, and Bali) are found an Asian flora and fauna such as tigers, elephants, orangutans, monkeys, rhinos, rich dipterocarp forests, and Rafflesia flowers (the largest on Earth). Further to the east, the biota of New Guinea is unique: no tigers or monkeys are found there, but instead are Australasian species such as tree kangaroos, echidnas (egg-laying mammals), cuscuses, birds of paradise, an amazing profusion of endemic orchids, and Klinki Pines (the world’s tallest tropical trees).

©M.Moore

Between the two biogeographic regions is Wallacea – named after noted 19th Century explorer and biologist Alfred Russel Wallace, co-discoverer with Charles Darwin of the theory of evolution through natural selection. Wallacea is a zone of mixing between Asian and Australasian biotic elements. On some islands, such as Sulawesi, Nusa Tenggara, and the Moluccas (known as the fabled “Spice Islands” to the explorer Columbus), are important species found nowhere else, such as the babirusa (“pigdeer”), the Komodo Dragon, and Wallace’s Standardwing Bird of Paradise. In Micronesia to the north, and in other parts of Melanesia to the west lie other important island chains containing many other unique animals and plants. Since many of these islands lie such a great distance from other lands, their biota have evolved in isolation, and hence many species are found only on certain islands and nowhere else.

While terrestrial biotas are often unique to a particular island or island group, all the Indo-Pacific shares a rich marine diversity – by far the richest and most important on the planet. The Indo-Pacific is located at the center of the so called “Coral Triangle”, the epicenter of global marine diversity. While the entire Caribbean basin has about 60 species of corals, for example, the island of New Guinea has an estimated 700 or more.

Tree Kangaroo ©George Steinmetz, Forest images©M.Moore

Despite the Indo-Pacific’s unsurpassed biological richness, many species are in immediate danger of extinction. The number of current extinctions globally and regionally, in fact, rivals that of the end of the Age of Dinosaurs. Species are going extinct thousands of times faster than new ones can evolve. Given the increasing scale and scope of current threats such as logging, agricultural expansion, and increasing demographic pressures on natural resources, new conservation strategies and fieldwork with local governments and communities are clearly necessary if biodiversity in the Indo-Pacific is to be protected.

Integrally linked to the biodiversity of the region is the extraordinary cultural diversity of the Indo-Pacific. The democratic nation of Papua New Guinea has 817 distinct ethnic groups – which makes it, despite its relatively small size, easily the most culturally diverse country on the planet. Indonesia is similarly rich, possessing at least 712 distinct ethnic groups. There are also approximately 263 ethnolinguistic groups in the rest of Micronesia, Polynesia, and Melanesia. This diversity is a source of vitality and strength, but it also requires of conservation a keen sensitivity to local and national complexities and perspectives. The cultural integrity of many traditional communities is closely linked with biodiversity conservation, since local peoples depend on their biota for food, fuel, medicines, and shelter. Absent new population pressures or the introduction of more advanced hunting technology, traditional use of forest and marine resources is typically consistent with effective conservation management.

New Guinea Biodiversity

New Guinea is the emerald jewel of Indo-Pacific biodiversity. Though occupying less than 0.5% of the earth’s land surface, New Guinea supports 5–9% of the planet’s biodiversity – about the same amount as the United States or Australia. Much of New Guinea’s biota is unique to the island. Yet rampant habitat destruction and degradation – through logging, agricultural settlement, introduced exotic species, and the like – is rapidly increasing in scale and scope, posing a serious threat to many species and ecosystems and the human communities who depend on them.

Located just north of Australia, New Guinea is the largest and highest tropical island in the world. Slightly bigger than the state of Texas, the island is divided politically between the Indonesian province of Papua (Irian Jaya) and the independent state of Papua New Guinea (PNG). The island possesses extremely rugged terrain, containing the highest mountains between the Himalayas and the Andes. In New Guinea are nearly all the world’s ecosystem types: glaciers, alpine tundra, savanna, montane and lowland rainforest, mangroves, wetlands, lake and river ecosystems, seagrasses, and some of the richest coral reefs on the planet.

New Guinea has most of the world’s species of birds-of-paradise, kangaroos that live in trees, mammals that lay eggs instead of birthing live young, an estimated 5,000 species of butterflies and moths, and well over 3,000 species of orchids.

The island is also home to an extraordinary human diversity, with over 1,000 living languages – nearly one-sixth of the world total. Found on this island are the tallest tropical trees in world, the world’s largest butterflies, the smallest parrot, the biggest orchid, the longest lizards, and many other superlatives. New Guinea is also located at the heart of the so-called Coral Triangle – the epicenter of global marine biodiversity.

Although New Guinea has the world’s third largest intact rainforest after the Amazon and Congo, these forests and reefs are being lost at an alarming and accelerating rate, threatening to obliterate a large amount of the island’s biodiversity before it can be fully studied or conserved. Today, New Guinea retains only about 40% of its original forest cover, and this remainder is quickly being lost due to agricultural conversion, rural development associated with high rates of human population growth, and felling for timber exports. New concession plans target nearly 80% of the forests on the island for either logging or agricultural conversion.