Madagascar lowland forests
Encyclopedia
The Madagascar lowland forests are a tropical moist broadleaf forest
ecoregion
, found on the eastern coast of the island of Madagascar
.
The lowland forests extend from Marojejy in the north to the southeast corner of the island. At the northern edge of ecoregion around Vohemar
, the moist forests transition to the drier Madagascar dry deciduous forests
ecoregion. To the east, at approximately 800 meters elevation, the lowland forests transition gradually to the Madagascar subhumid forests
ecoregion. The southern end of the ecoregion lies at the crest of the Anosyennes Mountains, where a narrow belt of dry transitional forest marks the transition to the xeric
Madagascar spiny thickets
ecoregion in the mountains' rain shadow
.
, Diospyros
, Ocotea
, Symphonia
, and Tambourissa
; emergents of Canarium
, Albizia
, and Brochoneura acuminata rise above the canopy. The lowland forests have a rich diversity of Pandanus
, bamboo
, and epiphytic
orchid species.
Madagascar's lowland rainforests have been preserved generally better than the high central plateau
, presumably due to historically less population density and longer distance to the capital city via marginal highway. There has been widespread slash-and-burn activity in the lowland rainforests, reducing certain forest habitat
and applying pressure to some endangered species
. Slash-and-burn is a method sometimes used by shifting cultivators
to create short term yields from marginal soils. When practiced repeatedly, or without intervening fallow periods, the nutrient
-poor soils may be exhausted or eroded to an unproductive state. These habitat loss impacts are especially significant because of the inherent biodiversity and high endemism of these rainforests. An interesting feature of these rainforests is the presence of Pachypodium habitats, often associated with xeric islands created by locally efficient drainage.
. nearly all of Madagascar's endemic mammal genera are represented there, including all five families of lemur
s. 15 species and subspecies of lemurs are endemic and near-endemic to the ecoregion, including the Aye-aye
(Daubentonia madagascariensis), the Hairy-eared Dwarf Lemur
(Allocebus trichotis), both species of ruffed lemur
s (Varecia variegata, V. rubra), the Indri
(Indri indri), the Eastern Woolly Lemur
(Avahi laniger), the Diademed Sifaka
(Propithecus diadema), Milne-Edwards' Sifaka
(P. edwardsi), the Golden Bamboo Lemur
(Hapalemur aureus), the Greater Bamboo Lemur
(Prolemur simus), the Gray-headed Lemur
(Eulemur cinereiceps), the Collared Brown Lemur
(E. collaris), and the Red-bellied Lemur
(E. rubriventer).
, Mananara Biosphere Reserve (including Verezanantsoro National Park), Ambatovaky Special Reserve, and Zahamena Integral Nature Reserve and National Park
.
Tropical and subtropical moist broadleaf forests
Tropical and subtropical moist broadleaf forests , also known as tropical moist forests, are a tropical and subtropical forest biome....
ecoregion
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
, found on the eastern coast of the island of Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
.
Setting
The ecoregion constitutes a narrow strip of lowland forests between Madagascar's east coast and the mountainous central highlands, from sea level to 800 meters elevation. It covers an area of approximately 112,600 square kilometers. The ecoregion is under the direct influence of the moist southeast trade winds, which maintain a warm, humid climate.The lowland forests extend from Marojejy in the north to the southeast corner of the island. At the northern edge of ecoregion around Vohemar
Vohemar
Vohemar is a coastal city and commune in northern Madagascar. It belongs to the district of Vohemar, which is a part of Sava Region. The population of the commune was estimated to be approximately 15,000 in 2001 commune census....
, the moist forests transition to the drier Madagascar dry deciduous forests
Madagascar dry deciduous forests
The Madagascar dry deciduous forests represent a tropical dry forest ecoregion generally situated in the western part of Madagascar. The area has high numbers of endemic plant and animal species but has suffered large-scale clearance for agriculture...
ecoregion. To the east, at approximately 800 meters elevation, the lowland forests transition gradually to the Madagascar subhumid forests
Madagascar subhumid forests
The Madagascar subhumid forests are a tropical moist broadleaf forest ecoregion which originally covered most of the Central Highlands of the island of Madagascar.-Setting:...
ecoregion. The southern end of the ecoregion lies at the crest of the Anosyennes Mountains, where a narrow belt of dry transitional forest marks the transition to the xeric
Deserts and xeric shrublands
Deserts and xeric shrublands is a biome characterized by, relating to, or requiring only a small amount of moisture.-Definition and occurrence:...
Madagascar spiny thickets
Madagascar spiny thickets
The Madagascar spiny thickets is an ecoregion in Madagascar. The vegetation type is found on poor substrates with low, erratic winter rainfall. An estimated 14,000 to is covered with this habitat, all in the southwest of the country...
ecoregion in the mountains' rain shadow
Rain shadow
A rain shadow is a dry area on the lee side of a mountainous area. The mountains block the passage of rain-producing weather systems, casting a "shadow" of dryness behind them. As shown by the diagram to the right, the warm moist air is "pulled" by the prevailing winds over a mountain...
.
Flora
The lowland forests are characterized by dense evergreen forests, with a canopy exceeding 30 meters. Typical canopy species include DalbergiaDalbergia
Dalbergia is a large genus of small to medium-size trees, shrubs and lianas in the pea family, Fabaceae, subfamily Faboideae. The genus has a wide distribution, native to the tropical regions of Central and South America, Africa, Madagascar and southern Asia...
, Diospyros
Diospyros
Diospyros is a genus of about 450–500 species of deciduous and evergreen trees. The majority are native to the tropics, with only a few species extending into temperate regions. They are commonly known as ebony or persimmon trees...
, Ocotea
Ocotea
Ocotea is a genus of flowering plants belonging to the family Lauraceae. The genus includes over 200 species of evergreen trees and shrubs, distributed mostly in tropical and subtropical regions of Central and South America, the West Indies, also with a few species in Africa and Madagascar, and...
, Symphonia
Symphonia (plant)
Symphonia is a genus of tropical woody plants, specifically trees in the family Clusiaceae. The genus has its diversity center in Madagascar and one species disjunct in the Afrotropic and the Neotropic in the Amazon Rainforest.Because of this particular distribution pattern, the origin of the...
, and Tambourissa
Tambourissa
Tambourissa is a genus of plant in family Monimiaceae. It contains the following species :* Tambourissa cocottensis, Lorence* Tambourissa pedicellata, Baker...
; emergents of Canarium
Canarium
Canarium is a genus of about 75 species of tropical and subtropical trees in the family Burseraceae, native to tropical Africa, southern Asia, and Australia, from southern Nigeria east to Madagascar, Mauritius, India, southern China, Indonesia and the Philippines...
, Albizia
Albizia
Albizia is a genus of about 150 species of mostly fast-growing subtropical and tropical trees and shrubs in the subfamily Mimosoideae of the legume family, Fabaceae. The genus is pantropical, occurring in Asia, Africa, Madagascar, Central, South, and southern North America and Australia, but mostly...
, and Brochoneura acuminata rise above the canopy. The lowland forests have a rich diversity of Pandanus
Pandanus
Pandanus is a genus of monocots with about 600 known species. They are numerous palmlike dioecious trees and shrubs native of the Old World tropics and subtropics. They are classified in the order Pandanales, family Pandanaceae.-Overview:...
, bamboo
Bamboo
Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....
, and epiphytic
Epiphyte
An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...
orchid species.
Madagascar's lowland rainforests have been preserved generally better than the high central plateau
Plateau
In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...
, presumably due to historically less population density and longer distance to the capital city via marginal highway. There has been widespread slash-and-burn activity in the lowland rainforests, reducing certain forest habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
and applying pressure to some endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
. Slash-and-burn is a method sometimes used by shifting cultivators
Shifting cultivation
Shifting cultivation is an agricultural system in which plots of land are cultivated temporarily, then abandoned. This system often involves clearing of a piece of land followed by several years of wood harvesting or farming, until the soil loses fertility...
to create short term yields from marginal soils. When practiced repeatedly, or without intervening fallow periods, the nutrient
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
-poor soils may be exhausted or eroded to an unproductive state. These habitat loss impacts are especially significant because of the inherent biodiversity and high endemism of these rainforests. An interesting feature of these rainforests is the presence of Pachypodium habitats, often associated with xeric islands created by locally efficient drainage.
Fauna
The lowland forests represent a great reservoir of diversity and endemismEndemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
. nearly all of Madagascar's endemic mammal genera are represented there, including all five families of lemur
Lemur
Lemurs are a clade of strepsirrhine primates endemic to the island of Madagascar. They are named after the lemures of Roman mythology due to the ghostly vocalizations, reflective eyes, and the nocturnal habits of some species...
s. 15 species and subspecies of lemurs are endemic and near-endemic to the ecoregion, including the Aye-aye
Aye-aye
The aye-aye is a lemur, a strepsirrhine primate native to Madagascar that combines rodent-like teeth and a special thin middle finger to fill the same ecological niche as a woodpecker...
(Daubentonia madagascariensis), the Hairy-eared Dwarf Lemur
Hairy-eared Dwarf Lemur
The hairy-eared dwarf lemur , or hairy-eared mouse lemur, is a nocturnal lemur endemic to Madagascar. It is the only member of the genus Allocebus. This species is critically endangered and the population is estimated at 100-1000 individuals. They all live a single location in the northeastern part...
(Allocebus trichotis), both species of ruffed lemur
Ruffed lemur
The ruffed lemurs of the genus Varecia are strepsirrhine primates and the largest extant lemurs within the family Lemuridae. Like all living lemurs, they are found only on the island of Madagascar...
s (Varecia variegata, V. rubra), the Indri
Indri
The indri , also called the babakoto, is one of the largest living lemurs. It is a diurnal tree-dweller related to the sifakas and, like all lemuroids, it is native to Madagascar.- Etymology :...
(Indri indri), the Eastern Woolly Lemur
Eastern Woolly Lemur
The eastern woolly lemur , also known as the eastern avahi or Gmelin's woolly lemur, is a species of woolly lemur native to eastern Madagascar, where it lives in humid forests. This nocturnal animal weighs 1-1.3 kg and reaches a length of 27–29 cm with a tail of 33–37 cm...
(Avahi laniger), the Diademed Sifaka
Diademed Sifaka
The diademed sifaka , or diademed simpona, is an endangered species of sifaka, one of the lemurs endemic to certain rainforests in eastern Madagascar. This species is one of the world's largest living lemurs, with a total adult length of approximately 105 centimetres , half of which is tail...
(Propithecus diadema), Milne-Edwards' Sifaka
Milne-Edwards' sifaka
Milne-Edwards' sifaka , or Milne-Edwards' simpona, is a large arboreal, diurnal lemur endemic to the eastern coastal rainforest of Madagascar. Milne-Edwards' sifaka is characterized by a black body with a light-colored "saddle" on the lower part of its back. It is closely related to the diademed...
(P. edwardsi), the Golden Bamboo Lemur
Golden Bamboo Lemur
The Golden Bamboo Lemur or Golden Lemur is a medium sized bamboo lemur endemic to southeastern Madagascar. It is listed as an endangered species due to habitat loss. The population is declining with only about 1000 individuals...
(Hapalemur aureus), the Greater Bamboo Lemur
Greater Bamboo Lemur
The Greater Bamboo Lemur , also known as the Broad-nosed Bamboo Lemur and the Broad-nosed Gentle Lemur, is the largest bamboo lemur, at over five pounds or nearly 2.5 kilograms. It has greyish brown fur and white ear tufts, and has a head-body length of around one and a half feet, or forty to...
(Prolemur simus), the Gray-headed Lemur
Gray-headed Lemur
The gray-headed lemur , or gray-headed brown lemur, is a medium-sized primate, a cathemeral species of lemur in the Lemuridae family. Until a taxonomic revision in 2008, it was known as the white-collared brown lemur or white-collared lemur . It lives in south-eastern Madagascar...
(Eulemur cinereiceps), the Collared Brown Lemur
Collared Brown Lemur
The collared brown lemur , also known as the red-collared brown lemur or red-collared lemur, is a medium-sized strepsirrhine primate and one of twelve species of brown lemur in the Lemuridae family. It is only found in south-eastern Madagascar. Like most species of lemur, it is arboreal, moving...
(E. collaris), and the Red-bellied Lemur
Red-bellied Lemur
The Red-bellied Lemur is a medium sized prosimian with a luxuriant chestnut brown coat. This lemur is endemic to eastern Madagascan rainforests and is distinguished by patches of white skin below the eyes, giving rise to a "teardrop" effect, particularly conspicuous in the male.The species, first...
(E. rubriventer).
Protected areas
It is estimated that only a third of the original lowland forest remains intact. Seven percent of the lowland forests that remain are protected in national parks and reserves, including Masoala National ParkMasoala National Park
Masoala National Park, in northeast Madagascar, is the largest of the island's protected areas. Most of the park is situated in Sava Region and a part in Analanjirofo. Created in 1997, the park protects 2,300 square kilometres of rainforest and 100 square kilometres of marine parks. The Masoala...
, Mananara Biosphere Reserve (including Verezanantsoro National Park), Ambatovaky Special Reserve, and Zahamena Integral Nature Reserve and National Park
Zahamena National Park
Zahamena National Park is a national Park of Madagascar. It is part of the World Heritage Site, Rainforests of the Atsinanana....
.