Borneo


Borneo is the third-largest island in the world, with an area of, and population of 23,053,723. Situated at the geographic centre of Maritime Southeast Asia, it is one of the Greater Sunda Islands, located north of Java, west of Sulawesi, and east of Sumatra. The island is crossed by the equator, which divides it roughly in half. In Indonesia, the island is also known as Kalimantan, which is also the name of the Indonesian region located on the island.
The geology of Borneo was formed beginning in the Mesozoic. It formed part of Sundaland, a region connected to mainland Asia, until it became isolated by sea level rise at the end of the last ice age. With seven unique ecoregions, including large expanses of some of the oldest tropical rainforests in the world, Borneo is rich in biodiversity and endemic species.
Archaeological evidence suggests Borneo has been inhabited by humans for more than 65,000 years. Borneo is home to hundreds of different Indigenous groups, cultures and languages, loosely grouped under the term "Dayak". International trading ports were well established on Borneo by the first millennium. It was later subsumed into the Majapahit Empire. The Sultanate of Sulu later ruled much of the island's North, and at its peak in the 14th century, the Sultanate of Brunei governed most of its coast; meanwhile, Borneo's interior remained largely outside of their control. Borneo was later colonised by the British and Dutch, and occupied by Japan during World War II.
Since the decolonisation of Asia, the island has been politically divided among three states, with the borders broadly following previous demarcation between the British and Dutch. The sovereign state of Brunei in the north makes up 1% of the territory. Approximately 73% of Borneo is Indonesian territory, and in the north, the East Malaysian states of Sabah and Sarawak make up about 26% of the island. The Malaysian federal territory of Labuan is situated on a small island just off the coast of Borneo.
The majority of Borneo's inhabitants reside in coastal cities. It is the site of Indonesia's planned future capital, Nusantara. Major economic sectors include oil and gas, agriculture, timber and tourism. Industrial deforestation in Indonesian and Malaysian Borneo for timber and agricultural conversion has taken place during the past century.

Etymology

When the sixteenth-century Portuguese explorer Jorge de Menezes made contact with the indigenous people of Borneo, they referred to their island as Pulu K'lemantang, and this second word became Kalimantan, the name for modern-day Borneo in the Indonesian language. The term kelamantan is used in Sarawak to refer to a group of people who consume sago in the northern part of the island.
According to Crawfurd, the word kelamantan is the name of a type of mango, though he adds that the word is fanciful and unpopular. The local mango, called klemantan, is still widely found in rural Ketapang and surrounding areas of West Kalimantan.
Another source states that it derives from the Sanskrit word kalamanthana, meaning "burning weather", possibly to describe the island's hot and humid tropical weather. In the Indianized Malay era the name Kalamanthana was derived from the Sanskrit terms kala and manthana, which possibly describes the hot weather.
Internationally, the island is known as Borneo, a name derived from European contact with the Brunei kingdom in the 16th century, during the Age of Exploration. On a map from around 1601, Brunei city is referred to as Borneo, and the whole island is also labelled Borneo. The name may derive from the Sanskrit word , meaning either "water" or Varuna, the Hindu god of rain and oceans.
In 977, Chinese records began to use the term Bo-ni to refer to Borneo. In 1225, it was also mentioned by the Chinese official Chau Ju-Kua. The Javanese manuscript Nagarakretagama, written by Majapahit court poet Mpu Prapanca in 1365, mentions the island as Nusa Tanjungnagara, which means the "island of the Tanjungpura Kingdom".
In Modern Chinese, the island is called 婆羅洲, the first two characters being phonetic and the third referring to a large landmass.

Geography

Geology

Borneo was formed through Mesozoic accretion of microcontinental fragments, ophiolite terranes and island arc crust onto a Paleozoic continental core. At the beginning of the Cenozoic, Borneo formed a promontory of Sundaland which partly separated from Asian mainland by the proto-South China Sea. The oceanic part of the proto-South China Sea was subducted during the Paleogene period and a large accretionary complex formed along the northwestern of the island of Borneo. In the early Miocene uplift of the accretionary complex occurred as a result of underthrusting of thinned continental crust in northwest. The uplift may have also resulted from shortening due to the counter-clockwise rotation of Borneo between 20 and 10 mega-annum as a consequence of Australia–Southeast Asia collision. Large volumes of sediment were shed into basins, which scattered offshore to the west, north and east of Borneo as well into a Neogene basin which is currently exposed in large areas of eastern and southern Sabah. In southeast Sabah, the Miocene to recent island arc terranes of the Sulu Archipelago extend onshore into Borneo with the older volcanic arc was the result of southeast dipping subduction while the younger volcanics are likely resulted from northwest dipping subduction the Celebes Sea.
Before sea levels rose at the end of the last ice age, Borneo was part of the mainland of Asia, forming, with Java and Sumatra, the upland regions of a peninsula that extended east from present day Indochina. The South China Sea and Gulf of Thailand now submerge the former low-lying areas of the peninsula. Deeper waters separating Borneo from neighbouring Sulawesi prevented a land connection to that island, creating the divide known as Wallace's Line between Asian and Australia-New Guinea biological regions. The island today is surrounded by the South China Sea to the north and northwest, the Sulu Sea to the northeast, the Celebes Sea and the Makassar Strait to the east, and the Java Sea and Karimata Strait to the south. To the west of Borneo are the Malay Peninsula and Sumatra. To the south and east are islands of Indonesia: Java and Sulawesi, respectively. To the northeast are the Philippine Islands. With an area of, it is the third-largest island in the world, and is the largest island of Asia. Its highest point is Mount Kinabalu in Sabah, Malaysia, with an elevation of.
The largest river system is the Kapuas in West Kalimantan, with a length of. Other major rivers include the Mahakam in East Kalimantan, the Barito, Kahayan, and Mendawai in South Kalimantan, Rajang in Sarawak and Kinabatangan in Sabah. Borneo has significant cave systems. In Sarawak, the Clearwater Cave has one of the world's longest underground rivers while Deer Cave is home to over three million bats, with guano accumulated to over deep. The Gomantong Caves in Sabah has been dubbed as the "Cockroach Cave" due to the presence of millions of cockroaches inside the cave. The Gunung Mulu National Park in Sarawak and Sangkulirang-Mangkalihat Karst in East Kalimantan which particularly a karst areas contains thousands of smaller caves.

Ecology

The Borneo rainforest is estimated to be around 140 million years old, making it one of the oldest rainforests in the world. The current dominant tree group, the dipterocarps, has dominated the Borneo lowland rain forests for millions of years. It is the centre of the evolution and distribution of many endemic species of plants and animals, and the rainforest is one of the few remaining natural habitats for the endangered Bornean orangutan. It is an important refuge for many endemic forest species, including the Borneo elephant, the eastern Sumatran rhinoceros, the Bornean clouded leopard, the Bornean rock frog, the hose's palm civet and the dayak fruit bat.
Peat swamp forests occupy the entire coastline of Borneo. The soil of the peat swamp is comparatively infertile, while it is known to be the home of various bird species such as the hook-billed bulbul, helmeted hornbill and rhinoceros hornbill. There are about 15,000 species of flowering plants with 3,000 species of trees, 221 species of terrestrial mammals and 420 species of resident birds in Borneo. There are about 440 freshwater fish species in Borneo. The Borneo river shark is known only from the Kinabatangan River. In 2010, the World Wide Fund for Nature stated that 123 species have been discovered in Borneo since the "Heart of Borneo" agreement was signed in 2007.
The WWF has classified the island into seven distinct ecoregions. Most are lowland regions:
According to analysis of data from Global Forest Watch, the Indonesian portion of Borneo lost of tree cover between 2002 and 2019, of which was primary forest, compared with Malaysian Borneo's of tree cover loss and of primary forest cover loss. As of 2020, Indonesian Borneo accounts for 72% of the island's tree cover, Malaysian Borneo 27%, and Brunei 1%. Primary forest in Indonesia accounts for 44% of Borneo's overall tree cover.

Environmental issues

The island historically had extensive rainforest cover, but the area was reduced due to heavy logging by the Indonesian and Malaysian wood industry, especially with the large demands of raw materials from industrial countries along with the conversion of forest lands for large-scale agricultural purposes. Half of the annual global tropical timber acquisition comes from Borneo. Palm oil plantations have been widely developed and are rapidly encroaching on the last remnants of primary rainforest. Forest fires since 1997, started by the locals to clear the forests for plantations were exacerbated by an exceptionally dry El Niño season, worsening the annual shrinkage of the rainforest. During these fires, hotspots were visible on satellite images and the resulting haze frequently affected Brunei, Indonesia and Malaysia. The haze could also reach southern Thailand, Cambodia, Vietnam and the Philippines as evidenced on the 2015 Southeast Asian haze.
A study in 2018 found that Bornean orangutans declined by 148,500 individuals from 1999 to 2015.