Borneo lowland rain forests

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Borneo lowland rain forests
Dipterocarp Forest at Danum Valley (13997709808).jpg
Primary lowland forest at Danum Valley, Sabah
Ecoregion IM0102.svg
Map of the Borneo lowland rain forests ecoregion
Ecology
Realm Indomalayan
Biome tropical and subtropical moist broadleaf forests
Borders
Geography
Area425,124 km2 (164,141 sq mi)
Countries
Conservation
Conservation status vulnerable, [1] nature could reach half protected [2]
Protected6.267% [3]

The Borneo lowland rain forests is an ecoregion, within the tropical and subtropical moist broadleaf forests biome, of the large island of Borneo in Southeast Asia. [1] It supports approximately 15,000 plant species, 380 bird species and several mammal species. The Borneo lowland rain forests is diminishing due to logging, hunting and conversion to commercial land use.

Contents

Location and description

The Borneo lowland rain forests cover an area of 428,438 square kilometers, about 57% of Borneo's land area. They cover most of the island below 1000 meters elevation. Borneo is divided between Indonesia, Malaysia, and Brunei, and the lowland rainforests extend into all three countries. [3]

Other ecoregions cover portions of lowland Borneo, including the Borneo peat swamp forests, Southwest Borneo freshwater swamp forests, and Sundaland heath forests. These other lowland ecoregions formed over specific soil conditions, and are home to distinct communities of plants and animals. The Sunda Shelf mangroves fringe the island's shores. [1]

The highlands of Borneo are home to the Borneo montane rain forests, which are distinct from the lowland forests in both forest structure and species composition. [1]

The lowlands are distinguished by climate (as the eastern side of the island is drier) or separated by the large Kapuas River and Barito River, which prevent animals and reptiles from spreading freely around the island.

Climate

Lowland Borneo has a stable tropical wet climate, with monthly rainfall exceeding 200 millimetres (7.9 in) throughout the year, and a temperature that rarely varies by more than 10°C. [1]

Flora

Benuang in the Niah National Park, Sarawak Benuang (Octomeles sumatrana) big buttress (15660479965).jpg
Benuang in the Niah National Park, Sarawak

The lowlands of Borneo are home to the richest rainforest in the world. The climate provides an ideal growing environment for approximately 10,000 species of plant (more than in the whole continent of Africa). Among these are some 2,000 species of orchids and 3,000 species of trees, including 267 species of dipterocarps (family Dipterocarpaceae), of which 155 are endemic to Borneo. This makes the island the center of the world's diversity for dipterocarps. [1]

Mixed dipterocarp forests, including lowland and hill forests, are the predominant plant community. The forests have a closed canopy 24 to 36 meters high, with emergent trees up to 65 meters tall extending above the canopy. Dipterocarps are the most common emergents, comprising up to 80% of the emergent stratum. The dipterocarp genera Dipterocarpus, Dryobalanops , and Shorea are typically emergents, while the dipterocarp genera Hopea and Vatica are common canopy trees. Koompassia excelsa (Fabaceae) is an emergent tree with a distinctive white trunk that can reach up to 85 meters high. Trees from the plant families Burseraceae and Sapotaceae are also common in the canopy. [1]

There is an understorey stratum under the canopy, composed of shade-tolerant trees draped with lianas and epiphytic orchids and ferns. Understorey trees are commonly of the plant families Euphorbiaceae, Rubiaceae, Annonaceae, Lauraceae, and Myristicaceae. Cauliflory – trees which bear flowers and fruits on their trunks – is common among understorey trees, including the forest durian ( Durio testudinarius ). Forest floor plants include five species of the strong-smelling parasite Rafflesia , one of which, Rafflesia arnoldii , has flowers over a metre wide, making it the world's largest flower. [1]

The limestone uplands of the Sangkulirang Peninsula and Sarawak support their own particular plant communities, as do the Labi Hills on the Brunei-Sarawak border. [1]

Fauna

The critically endangered Bornean orangutan, a great ape endemic to Borneo, in Tanjung Puting Bornean orangutan (Pongo pygmaeus), Tanjung Putting National Park 11.jpg
The critically endangered Bornean orangutan, a great ape endemic to Borneo, in Tanjung Puting
Borneo elephant Pygmy Elephant (Elephas maximus borneensis) (8071012817).jpg
Borneo elephant

The wildlife of this ecoregion consists of a large number of forest animals ranging from the world's smallest squirrel, the least pygmy squirrel, to the largest land mammal in Asia, the Asian elephant. It includes the critically endangered Sumatran rhinoceros, the endangered and iconic Bornean orangutan, twelve other species of primate, Bornean bearded pigs and Bornean yellow muntjac deer. The primates of Borneo are: three apes (Bornean orangutan, Müller's Bornean gibbon and Bornean white-bearded gibbon), five langurs, the southern pig-tailed macaque, long-tailed macaque, Horsfield's tarsier (Tarsius bancanus), Bornean slow loris (Nycticebus borneanus), Kayan slow loris (Nycticebus kayan), Philippine slow loris (Nycticebus menagensis), Bangka slow loris (Nycticebus bancanus), and the endangered proboscis monkey (Nasalis larvatus). There are no tigers on Borneo; carnivores include the endangered Bornean clouded leopard (Neofelis diardi borneensis), the sun bear (Helarctos malayanus), the otter civet (Cynogale bennettii), and several other mustelids and viverrids. [1]

The 380 species of birds include eight hornbills, eighteen woodpeckers and thirteen pittas. There are nine near-endemic and two endemic birds; the black-browed babbler (Malacocincla perspicillata) and the white-crowned shama (Copsychus stricklandii). Among the rich variety of reptiles and amphibians are crocodiles and the earless monitor lizard (Lanthanotus borneensis). The sounds of the forest vary from day to night as different combinations of these birds and animals emerge to roam and feed. [1]

Biogeography

During the Pleistocene glacial epoch, all of Borneo, Java, Sumatra, and mainland Indochina were part of the same landmass, called Sundaland. This allowed plants and animals to migrate from one region to the next. Now Borneo is separated from the Malay Peninsula and the islands, but it still shares a lot of the same plant and animal diversity, while Sulawesi has less Borneo wildlife.

Threats and preservation

Logging in Sabah, Malaysian Borneo Logs DSC 9204.JPG
Logging in Sabah, Malaysian Borneo
New palm plantation (right), Tabin Wildlife Reserve Tabin Wildlife Reserve (14839986368).jpg
New palm plantation (right), Tabin Wildlife Reserve

Logging and conversion of natural forests to rubber, oil palm and industrial timber plantations and for small-scale farming have given rise to significant deforestation in recent decades. Borneo has lost more than half of its rainforests in the past half a century. [4] In 198283 and again in 199798, forest fires in Kalimantan cleared around 25,000 km2 (9,700 sq mi) each time for oil palm planting. Further threats in Sabah come from exploration for oil and coal in the Maliau Basin and the draining of the wetlands on the Klias Peninsula. In 2001, the World Wildlife Foundation forecast that "If the current trend of habitat destruction continues, there will be no remaining lowland forests in Borneo by 2010." [1] Although this forecast has not been fulfilled, in 2008 the IUCN Red List reported a 2005 prediction that "forest cover on the island of Borneo, if current deforestation rates continue, is projected to decline from 50% to less than one-third by 2020". [5]

Protected areas

Danum Valley Conservation Area in Sabah Primary Rainforest (10623380025).jpg
Danum Valley Conservation Area in Sabah

6.267% of the ecoregion is in protected areas. These include: [3]

Related Research Articles

<span class="mw-page-title-main">Tropical and subtropical moist broadleaf forests</span> Habitat type defined by the World Wide Fund for Nature

Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature.

<span class="mw-page-title-main">Madagascar lowland forests</span> Ecoregion in Eastern Madagascar

The Madagascar lowland forests or Madagascar humid forests are a tropical moist broadleaf forest ecoregion found on the eastern coast of the island of Madagascar, home to a plant and animal mix that is 80 to 90% endemic, with the forests of the eastern plain being a particularly important location of this endemism. They are included in the Global 200 list of outstanding ecoregions.

<span class="mw-page-title-main">Sundaland heath forests</span> WWF ecoregion

The Sundaland heath forests, also known as Kerangas forest, is a type of tropical moist forest found on the island of Borneo, which is divided between Brunei, Indonesia, and Malaysia, as well as on the Indonesian islands of Belitung and Bangka, which lie to the west of Borneo.

<span class="mw-page-title-main">Danum Valley Conservation Area</span> Protected area in Sabah, Malaysia

Danum Valley Conservation Area is a 438 square kilometres tract of relatively undisturbed lowland dipterocarp forest in Sabah, Malaysia. It has an extensive diversity of tropical flora and fauna, including such species as the rare Bornean orangutans, gibbons, mousedeer, clouded leopards and over 270 bird species. Activities offered are jungle treks, river swimming, bird watching, night jungle tours and excursions to nearby logging sites and timber mills.

<span class="mw-page-title-main">Borneo peat swamp forests</span> Ecoregion in Borneo

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<span class="mw-page-title-main">Tengku Hassanal Wildlife Reserve</span>

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<span class="mw-page-title-main">Lambir Hills National Park</span> National park in Malaysia

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<span class="mw-page-title-main">Betung Kerihun National Park</span> National park in Indonesia

Betung Kerihun National Park is a national park located in the Indonesian province of West Kalimantan, on the island of Borneo. The park was established in 1995, and has a total area of 8,000 km2 (3,100 sq mi) or about 5.5 percent of West Kalimantan Province area. Together with the 2,000 km2 (800 sq mi) Lanjak Entimau Wildlife Sanctuary in Malaysia, it has been proposed to form a World Heritage Site named the "Transborder Rainforest Heritage of Borneo".

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<span class="mw-page-title-main">Heart of Borneo</span> Inter-governmental conservation agreement

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<i>Nycticebus kayan</i> Species of primate

The Kayan River slow loris is a strepsirrhine primate and a species of slow loris that is native to the northern and central highland region of the island of Borneo. The species was originally thought to be a part of the Bornean slow loris (N. menagensis) population until 2013, when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it. It is distinguished by the high contrast of its black and white facial features, as well as the shape and width of the stripes of its facial markings.

The Bangka slow loris is a strepsirrhine primate and a species of slow loris that is native to southwestern Borneo and the island of Bangka. Originally considered a subspecies or synonym of the Bornean slow loris (N. menagensis), it was promoted to full species status in 2013 when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it as a separate species. It is distinguished by the crimson red fur on its back, light-colored facial features, as well as the shape and width of the stripes of its facial markings.

<span class="mw-page-title-main">Ulu Temburong National Park</span> National park in Brunei

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<span class="mw-page-title-main">Peninsular Malaysian rain forests</span> Ecoregion on the Malay Peninsula

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<span class="mw-page-title-main">Peninsular Malaysian montane rain forests</span> Ecoregion on the Malay Peninsula

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<span class="mw-page-title-main">Vogelkop–Aru lowland rain forests</span> Ecoregion in Indonesia

The Vogelkop–Aru lowland rain forests is a tropical moist forest ecoregion in Indonesia. The ecoregion covers the peninsular lowlands of western New Guinea, along with the Aru Islands and other nearby islands.

<span class="mw-page-title-main">Sumatran lowland rain forests</span> Ecoregion in Sumatra, Indonesia

The Sumatran lowland rain forests ecoregion covers the lowland forests running the length of the island of Sumatra in Indonesia. The region is one of exceptionally high biodiversity, similar to Borneo and New Guinea islands. Many endangered mammals species are present, and over 450 species of birds have been found in the region. In recent years, illegal logging and human encroachment have put great strain on this ecoregion.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 "Borneo lowland rain forests". Terrestrial Ecoregions. World Wildlife Fund. Retrieved 11 March 2023.
  2. Eric Dinerstein, David Olson, et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 1924, Pages 534–545; Supplemental material 2 table S1b.
  3. 1 2 3 Borneo lowland rain forests. DOPA Explorer. Accessed 11 March 2023.
  4. "What Causes Deforestation in Borneo and How Do We Stop It?". Earth.org. 2 March 2023.
  5. Hearn, A.; Brodie, J.; Cheyne, S.; Loken, B.; Ross, J. & Wilting, A. (2017) [errata version of 2016 assessment]. "Catopuma badia". IUCN Red List of Threatened Species . 2016: e.T4037A112910221. doi: 10.2305/IUCN.UK.2016-1.RLTS.T4037A50650716.en . Retrieved 14 December 2023.