The ecoregions of Madagascar, as defined by the

World Wildlife Fund The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the Wo ...

, include seven terrestrial, five freshwater, and two marine

ecoregions 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 ...

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

's diverse natural habitats harbour a rich

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as '' biota''. Zoo ...

and

flora Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or '' skin flora''. E ...

with high levels of

endemism Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

, but most ecoregions suffer from

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

Overview

belongs to the

Afrotropical realm The Afrotropical realm is one of Earth's eight biogeographic realms. It includes Africa south of the Sahara Desert, the majority of the Arabian Peninsula, the island of Madagascar, southern Iran and extreme southwestern Pakistan, and the island ...

. With its neighboring

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

islands, it has been classified by

botanist Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...

Armen Takhtajan Armen Leonovich Takhtajan or Takhtajian ( hy, Արմեն Լևոնի Թախտաջյան; russian: Армен Леонович Тахтаджян; surname also transliterated Takhtadjan, Takhtadzhi︠a︡n or Takhtadzhian, pronounced takh-tuh-JA ...

as ''Madagascan Region'', and in

phytogeography Phytogeography (from Greek φυτόν, ''phytón'' = "plant" and γεωγραφία, ''geographía'' = "geography" meaning also distribution) or botanical geography is the branch of biogeography that is concerned with the geographic distribution o ...

it is the floristic

phytochorion A phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phytochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both re ...

''Madagascan Subkingdom'' in the

Paleotropical Kingdom The Paleotropical Kingdom (Paleotropis) is a floristic kingdom comprising tropical areas of Africa, Asia and Oceania (excluding Australia and New Zealand), as proposed by Ronald Good and Armen Takhtajan. Part of its flora, inherited from the ancient ...

. Madagascar features very contrasting topography, climate, and geology. A mountain range on the east, rising to at its highest point, captures most rainfall brought in by

trade winds The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisph ...

from the Indian Ocean. Consequently, the eastern belt harbours most of the humid forests, while precipitation decreases to the west. The

rain shadow A rain shadow is an area of significantly reduced rainfall behind a mountainous region, on the side facing away from prevailing winds, known as its leeward side. Evaporated moisture from water bodies (such as oceans and large lakes) is carrie ...

region in the southwest has a sub-arid climate. Temperatures are highest on the west coast, with annual means of up to , while the high massifs have a cool climate, with a annual mean locally. Geology features mainly

igneous Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or ...

and

metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causin ...

basement rocks, with some

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

and

quartzite Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tect ...

in the central and eastern plateaus, while the western part has belts of

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

(including the

tsingy Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

formations), and unconsolidated sand.

Terrestrial ecoregions

Seven

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

are defined by the

for Madagascar. They range from the very humid eastern lowland forests to the sub-arid spiny thickets in the southwest.

Freshwater ecoregions

Lake Ravelobe, Ankarafantsika National Park, Madagascar

Freshwater 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 ...

s correspond to major

catchment A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...

areas with a distinctive assemblage of species. In Madagascar, five ecoregions are distinguished: * Madagascar Eastern Lowlands includes the lower humid-climate coastal plain of eastern Madagascar. * Madagascar Eastern Highlands includes the middle and upper catchments of Madagascar's eastern coastal rivers. * Northwestern Madagascar encompasses the westward-flowing drainage basins from the northern tip of Madagascar to the Mahavavy du Sud River, including the Mananjeba, North Mahavavy (Mahavavy du Nord),

Sambirano The Sambirano region, also known as the Sambirano domain, is a biogeographic region of northwestern Madagascar. It has a distinctive lowland climate with year-round rain, differing from the rest of seasonally-dry western and northern Madagascar. The ...

, Ankofia,

Sofia Sofia ( ; bg, София, Sofiya, ) is the capital and largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain in the western parts of the country. The city is built west of the Iskar river, and ha ...

Anjobony The Anjobony river in Sofia Region is located in northern Madagascar. It drains to the northern coast. Its main affluent is the Bemarivo (Sofia). near Boriziny (Port Bergé). It flows into the Sofia River The Sofia is a river of northwestern M ...

, Mahajamba,

Betsiboka Betsiboka is a Regions of Madagascar, region of Madagascar. It borders Boeny Region in north, Sofia Region, Sofia in northeast, Alaotra-Mangoro in east, Analamanga and Bongolava in south and Melaky in west. The capital of the region is Maevatanana. ...

, and

South Mahavavy The Mahavavy Sud, also known as the Mahavavy South, is a river in western Madagascar. It flows from south to north through the regions of Melaky, Betsiboka, and Boeny. It has a length of approximately 1000 km, and drains a basin of 16,475 km2. It i ...

(Mahavavy du Sud). * Western Madagascar encompasses the drier western river basins, including the

Manambolo ''For the river with the same name, see Manambolo (disambiguation)'' Manambolo is a town and commune ( mg, kaominina) in Madagascar. It belongs to the district of Maroantsetra, which is a part of Analanjirofo Region. The population of the commune ...

, Tsiribihina,

Mangoky The Mangoky River is a 564-kilometer-long (350 mi) river in Madagascar in the regions of Atsimo-Andrefana and Anosy. It is formed by the Mananantanana and the Matsiatra. Another important affluent is the Zomandao River. It rises in the Ce ...

, and Onilahy rivers. * Southern Madagascar encompasses the southern drainages of Madagascar, including the Mandrare, Manambovo, Menarandra, and Linta rivers, along with

Lake Tsimanampetsotsa Lake Tsimanampetsotsa (french: Lac Tsimanampetsotsa) (also called Lake Tsimanampesotse) is a moderately Soda lake, alkaline lake in the Toliara Province, in the southwestern part of Madagascar. It is located at around . The lake is protected wit ...

.Southern Madagascar
''Freshwater Ecoregions of the World''. Accessed 20 November 2022.

Marine ecoregions

The seas around Madagascar are part of the Western Indian Ocean province in the Western Indo-Pacific realm. They are divided into two

marine ecoregions A marine ecoregion is an ecoregion, or ecological region, of the oceans and seas identified and defined based on biogeographic characteristics. Introduction A more complete definition describes them as “Areas of relatively homogeneous species c ...

:Spalding, Mark D., Helen E. Fox, Gerald R. Allen, Nick Davidson et al. "Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas". ''Bioscience'' Vol. 57 No. 7, July/August 2007, pp. 573–583. * Southeast Madagascar * Western and Northern Madagascar

References

{{Ecoregions in Africa