The Palawan rain forests

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

(WWF ID:IM0143) covers the

Palawan Palawan (), officially the Province of Palawan ( cyo, Probinsya i'ang Palawan; tl, Lalawigan ng Palawan), is an archipelagic province of the Philippines that is located in the region of Mimaropa. It is the largest province in the country in ...

Island Archipelago, centered on

Palawan Island Palawan is the largest island of the province of Palawan in the Philippines and fifth-largest by area and tenth-most populous island of the country, with a total population of 994,101 as of 2020 census. The north west coast of the island is alon ...

, the sixth largest island in the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

. The islands act as an ecological bridge between

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

and the main islands of the Philippines, even though there were channels between the islands through the last ice age when sea levels were low. Biodiversity is high in the islands, with many endemic species, and with many genera shared with Borneo to the south. Pressure from logging is a concern for the forests of this region.

Location and description

In addition to the main island of

, the ecoregion includes

Balabac Island Balabac Island is the southernmost island of the Palawan province, and therefore the westernmost undisputed island in the Philippines, only about north from Sabah, Malaysia, across the Balabac Strait. Administratively, the island forms the m ...

to the south, Ursula Island, and the

Calamian Islands The Calamian Islands or the Calamianes is a group of islands in the province of Palawan, Philippines. It includes: * Busuanga Island * Coron Island * Culion Island * Calauit Island * Malcapuya Island * Banana Island * Pass Island * Calumbuyan Isl ...

to the north. Palawan Island is 260 km long and averages only 25–30 km wide. A mountain range runs up the middle of the island, with almost half of the slopes averaging over 30 degrees. The highest point is at

Mount Mantalingajan Mount Mantalingahan (or Mantalingahan or Mantaling) is the highest mountain in the island province of Palawan in the Philippines, with an elevation of above sea level, its ranked 68th-highest peak of an island on Earth and 10th-most prominent ...

. The islands are relatively young, having been lifted up from the sea only 5-10 million years ago.

Climate

The climate of the ecoregion is '' Tropical savanna climate - dry winter'' (

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...

(Aw)). This climate is characterized by relatively even temperatures throughout the year, and a pronounced dry season. The driest month has less than 60 mm of precipitation, and is drier than the average month. In the Palawans, the wet season lasts from June to October. The dry season for much of the island is November to May, but only a few months long in the north.

Flora

About two thirds of the islands is covered in closed broadleaf evergreen forest, 10% in other closed forest, 15% in open forest or herbaceous cover and only about 5% in human settlement or agriculture. Much of this forest below the highlands has been cut previously, and pressure from logging and conversion of land to agriculture has reduced the quality of much of the forest. The forests nearest the coast are beech forests, transitioning to lowland

rain forest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainforest ...

dominated by trees of the

Dipterocarpaceae Dipterocarpaceae is a family of 16 genera and about 695 known species of mainly tropical lowland rainforest trees. The family name, from the type genus ''Dipterocarpus'', is derived from Greek (''di'' = two, ''pteron'' = wing and ''karpos'' = fru ...

family, Agalai, various species of ''

Ficus ''Ficus'' ( or ) is a genus of about 850 species of woody trees, shrubs, vines, epiphytes and hemiepiphytes in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending in ...

'', Water gum ''( Tristania)'', Broad leaved ballart ''( Exocarpos latifolius)'', and '' Swintonia foxworthyi''. Montane rainforest is found at higher elevations (800 to 1,200 meters), and semi-deciduous forest is found in the rain shadow on the east side of the main island. The southern part of the main island has different forest types that depend on the soil. Large areas are limestone forest, featuring Cathedral cactus ''( Euphorbia trigona)'', ''( Aglaia argentea)'', ''

Antidesma ''Antidesma'' is a genus of tropical plant in the family Phyllanthaceae formally described by Linnaeus in 1753. It is native to tropical Africa, S + E + SE Asia, Australia, and various oceanic islands. The greatest diversity occurs in Southe ...

'', ''

Drypetes ''Drypetes'' is a plant genus of the family Putranjivaceae, in the order Malpighiales. It was previously in the family Euphorbiaceae, tribe Drypeteae, and was the sole pantropical zoochorous genus of the family. The genus comprises about 200 ...

'', and ''

Gomphandra ''Gomphandra'' is a genus of plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all ...

''. There are

ultramafic Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are composed ...

forests around Victoria Peak that support plants that may be associated with soils having heavy metals. Parts of the southern forest are dominated by ''

Casuarina ''Casuarina'' is a genus of 17 tree species in the family Casuarinaceae, native to Australia, the Indian subcontinent, southeast Asia, islands of the western Pacific Ocean, and eastern Africa. It was once treated as the sole genus in the fami ...

''.

Fauna

There are high levels of endemic species of mammals on the islands, but many of the genera are shared with Borneo, indicating that the Palawans were once part of

Sundaland Sundaland (also called Sundaica or the Sundaic region) is a biogeographical region of South-eastern Asia corresponding to a larger landmass that was exposed throughout the last 2.6 million years during periods when sea levels were lower. It ...

(the combined islands to the west), but have been separated for enough time to develop their own faunal communities.

Protected areas

Over 80% of the ecoregion is protected in some form. These protected areas include: *

Puerto Princesa Subterranean River National Park The Puerto Princesa Subterranean River National Park is a protected area in the Philippines. The park is located in the Saint Paul Mountain Range on the western coast of the island of Palawan, about north of the city of Puerto Princesa, and c ...

References

{{reflist Indomalayan ecoregions Ecoregions of the Philippines Tropical and subtropical moist broadleaf forests