Malay Archipelago
The Malay Archipelago, often referred to as the East Indies, is the largest island group in the world, consisting of over twenty-five thousand islands located between the Indian and Pacific Oceans. This extensive archipelago includes notable islands like Borneo, Sulawesi, Java, and Sumatra in Indonesia, as well as Luzon and Mindanao in the Philippines. The region is characterized by its diverse geography, with volcanic activity due to the convergence of multiple tectonic plates, leading to significant biodiversity and unique ecosystems. The climate is tropical, with average temperatures around 80 degrees Fahrenheit, and the area is prone to typhoons.
Home to a rich cultural tapestry, the Malay Archipelago has over two thousand languages spoken and primarily follows Islam, which was introduced in the thirteenth century. The economy is heavily reliant on agriculture, with crops such as rice, yams, and various commercial spices being significant. However, conservationists are increasingly concerned about biodiversity loss due to deforestation, illegal wildlife trade, and climate change, particularly in the Wallacea region, which is recognized for its unique wildlife and critical ecosystems. Despite its natural wealth, the archipelago faces numerous environmental challenges that threaten both its ecosystems and the livelihoods of its inhabitants.
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Malay Archipelago
The Malay Archipelago is the world's largest island group, comprising more than twenty-five thousand islands of Indonesia and the Philippines between the Indian and Pacific Oceans. It is also referred to as the East Indies. The islands include the Greater Sundas (Borneo, Sulawesi, Java, and Sumatra); the Lesser Sundas; the Moluccas; and western New Guinea in the Republic of Indonesia, as well as Luzon, Mindanao, and the Visayas in the Philippines. Political units of the archipelago include Brunei, East Malaysia, and Papua New Guinea. The archipelago encloses the Banda, Celebes, Flores, Java, Molucca, Savu, and Sulu Seas, and is separated from surrounding land areas by the Bashi Channel, South China Sea, Strait of Malacca, and Torres Strait.
The island group stretches more than 3,800 miles (6,200 kilometers) along the equator, and at its widest (north-south) is about 2,200 miles (3,500 kilometers). During the last ice age, about eleven thousand years ago, some of the islands were extensions of mainland Asia. Volcanic activity and uplift of tectonic plates have produced large mountains in the region.
Background
A number of tectonic plates converge in the region of the Malay Archipelago. The islands of Indonesia are primarily the result of the subduction of the Australia Plate beneath the Eurasia Plate, and volcanic activity along the seam of these plates. Islands in the Banda Sea are the result of the subduction of the Pacific Plate under the Eurasian Plate and volcanic activity. This region contains many volcanoes; seventy-six in Indonesia have erupted in recorded history. Indonesia has more than one thousand documented eruptions. The archipelago is also the result of glacial retreat. Glaciers are extremely heavy. When they melted at the end of the last ice age, the weight over the plate edges was removed. This permitted the submerged land to bounce upward very quickly. Subduction and uplift continue to raise the land slowly over time.
The Eurasian Plate to the west and the Philippine Plate to the east are slowly moving together. A microplate, the Molucca Sea Plate, is being subducted in the Sangihe subduction zone in the west and the Halmahera subduction zone in the east. In no more than five million years, the Molucca Sea Plate will be completely beneath the Eurasian and Philippine Plates, which will meet. The Molucca Sea Plate will form a dam that will prevent further volcanic activity.
The Sunda Shelf is a continental shelf off Southeast Asia's mainland that includes Indonesia's islands of Borneo, Java, and Sumatra. It lies beneath several shallow seas, including the Java Sea, Gulf of Thailand, and South China Sea. Deep areas along the southeast, south, and west are marked by volcanic activity. Across the southeastern deep is the Sahul Shelf, another continental shelf that is an extension of Australia's northern coast.
While most of the seas in this region are shallow, and the waters warm, the area is also marked by several deep trenches. In 1854, English naturalist Alfred Russel Wallace recognized the significance of one separation, a 15 mile (25 kilometer) wide strait that lies between Bali and Lombok. This narrow strait came to be called the Wallace Line. Wildlife and plants on Lombok and the other islands east of the Wallace Line are related to those found in Australia, while life on the western side of the strait originated in Asia. Wallace's realization led to the development of a new field of study, biogeography, before Charles Darwin expressed his ideas about natural selection. Darwin was astounded in 1858 when he received a letter and enclosed essay from Wallace, whose theories about the specimens in Indonesia closely mirrored Darwin's ideas about natural selection.
Overview
Almost all of the islands of the Malay Archipelago are within 10 degrees of the equator. Temperatures there average 80 degrees Fahrenheit (21 degrees Celsius). The region is prone to typhoons, which can bring high winds and heavy rainfall. Many of the islands are home to tropical rain forests, some of which were established up to one hundred million years ago.
The Malay are the primary people of the archipelago. More than two thousand languages are spoken across the islands. Islam arrived in the region about the thirteenth century, and is the primary religion. In rural areas, agriculture is a mainstay of the population. Cassava, corn, rice, and yams are among the primary food crops, and commercial crops include spices, sugar, tea, tobacco, and coffee. Some countries in the archipelago are exporters of petroleum—which is located beneath the Sunda Shelf—while several countries produce timber and metals such as tin and copper.
Conservationists have focused attention on Wallacea, the region around the Wallace Line. This region between the Australian and Oriental regions is an important zoogeographical area and a biodiversity hot spot. Geological findings indicate the unique history of the archipelago led to the biodiversity Wallace first observed and studied during the nineteenth century.
In the past, the region was repeatedly inundated by water as world sea levels rose and fell during the ice ages. People and animals migrated into these areas at various times. When sea levels were low, species could travel over land from mainland Asia. New species were introduced and developed during warm periods in relative isolation, adapting to other life-forms. Some rain forest species, developing in isolated pockets, eventually evolved to become distinct species that, meeting their biological cousins once again when the waters receded, could no longer interbreed.
In many cases, the majority of species in a taxonomic group in the region are native to these islands. Some species unique to the archipelago include anoas, babirusas, and maleos. Other animals include elephants, orangutans, rhinoceroses, and tigers. Many species are threatened due to illegal wildlife trade and poaching, as well as loss of habitat. The Critical Ecosystem Partnership Fund recognized Wallacea as an ecosystem in need of action to preserve biodiversity in 2013.
Deforestation is a significant issue in the region. Reliance on agriculture has prompted many people to clear land for farming, in particular oil palm plantations. Many acres are logged. Many people resort to burning to clear the land, a practice that contributes to sometimes debilitating air pollution. Growing urbanization and development threatens both the environment and wildlife. Climate change is affecting the forests as well as the corals in the region. Overfishing is also a concern. The Coral Triangle, an area of significant biodiversity, boasts 75 percent of Earth's coral species and 40 percent of reef fish species.
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