The Madagascar ericoid thickets is a montane shrubland

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 ...

, found at higher altitudes on

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 Afric ...

's four major mountains.

Geography

The ecoregion covers the area above 1800 m elevation on (from north to south) Tsaratanana (2,876 m),

Marojejy Marojejy National Park () is a national park in the Sava region of northeastern Madagascar. It covers and is centered on the Marojejy Massif, a mountain chain that rises to an elevation of . Access to the area around the massif was restrict ...

(2,133 m),

Ankaratra Ankaratra is a cinder cone volcano range located about southwest of Antananarivo, the capital city of Madagascar. It lies between the towns of Arivonimamo to the north, Ambatolampy to the east, Faratsiho to the west and Betafo to the south. It is ...

(2,643 m), and

Andringitra Massif The Andringitra Massif ("desert of rocks") is a granite massif located within Andringitra National Park in Madagascar. The range is approximately long. In its central area, the range is almost wide, though it is much narrower on either end. Pi ...

(2,658 m). The ericoid thickets are surrounded at lower elevations by the

Madagascar subhumid forests The Madagascar subhumid forests are a tropical moist broadleaf forest ecoregion that covers most of the Central Highlands of the island of Madagascar. They are included in the WWF's Global 200 list of outstanding ecoregions. Most of the origin ...

ecoregion. The total area of the ecoregion is . On Tsaratanana the thickets are higher up, starting above 2,500m. There are smaller areas of thicket in Anjanaharibe-Sud Special Reserve in the north and Andohahela National Park to the south.

Flora

The main plant community is thickets. The thickets are composed of evergreen woody shrubs and low trees, which form a single, often impenetrable stratum never more than 6 meters tall. The shrubs and trees typically have an ericoid habit, with short, twisted stems and ericoid, cupressoid, or myrtilloid leaves.White, Frank F. (1983). ''The vegetation of Africa: A descriptive memoir to accompany the Unesco/AETFAT/UNSO vegetation map of Africa''. UNESCO, 1983. ISBN 92-3-101955-4 Characteristic shrubs of the ericoid thickets are from the plant families

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae ...

(species of '' Psiadia,

Helichrysum The genus ''Helichrysum'' consists of an estimated 600 species of flowering plants in the sunflower family (Asteraceae). The type species is '' Helichrysum orientale''. They often go by the names everlasting, immortelle, and strawflower. The nam ...

Stoebe ''Stoebe'' is a genus of African plants in the tribe Gnaphalieae within the family Asteraceae. ; Species ; formerly included A few dozen species now regarded as members of other genera: ''Dicerothamnus Dolichothrix Disparago Gongyloglossa Heli ...

'', and '' Stenocline''),

Ericaceae The Ericaceae are a family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with c.4250 known species spread across 124 genera, making it th ...

(species of '' Erica,

Agauria Agarista may refer to: * Alternative spelling of Agariste, a name from Greek mythology * ''Agarista'' (moth), a genus of moths in the family Noctuidae * ''Agarista'' (plant), a genus of plants in the family Ericaceae {{disambiguation Genus dis ...

'', and ''

Vaccinium ''Vaccinium'' is a common and widespread genus of shrubs or dwarf shrubs in the heath family (Ericaceae). The fruits of many species are eaten by humans and some are of commercial importance, including the cranberry, blueberry, bilberry (whort ...

''),

Rhamnaceae The Rhamnaceae are a large family of flowering plants, mostly trees, shrubs, and some vines, commonly called the buckthorn family. Rhamnaceae is included in the order Rosales. The family contains about 55 genera and 950 species. The Rhamnaceae ...

('' Phylica''), and

Rubiaceae The Rubiaceae are a family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with interpetiolar stipules a ...

. Low trees, widely-spaced, rise a little higher than the shrub canopy. Native trees include ''

Agauria salicifolia Agarista may refer to: * Alternative spelling of Agariste, a name from Greek mythology * ''Agarista'' (moth), a genus of moths in the family Noctuidae * ''Agarista'' (plant), a genus of plants in the family Ericaceae {{disambiguation Genus dis ...

Ilex mitis ''Ilex mitis'' (commonly called Cape holly, African holly, waterboom or umDuma) is a tall, dense, evergreen tree that is indigenous to Sub-Saharan Africa and Madagascar. It makes an excellent fast-growing hedge for gardens - growing tall, strai ...

Neocussonia bojeri ''Neocussonia'' is a genus of flowering plants belonging to the family Araliaceae The Araliaceae are a family of flowering plants composed of about 43 genera and around 1500 species consisting of primarily woody plants and some herbaceous p ...

Razafimandimbisonia minor ''Razafimandimbisonia'' is a genus of flowering plants in the family Rubiaceae. It is endemic to Madagascar. Taxonomy The genus ''Alberta'' was shown to be paraphyletic in a phylogenetic analysis of the tribe Alberteae. The type species ' ...

Dodonaea madagascariensis ''Dodonaea'' is a genus of about 70 species of flowering plants, often known as hop-bushes, in the soapberry family, Sapindaceae. It has a cosmopolitan distribution in tropical, subtropical and warm temperate regions of Africa, the Americas, so ...

, Tambourissa gracilis,

Podocarpus rostratus ''Podocarpus rostratus'' is a species of conifer in the family Podocarpaceae. It is endemic to Madagascar. Range and habitat ''Podocarpus rostratus'' is native to the high-elevation ericoid thickets in Madagascar's highlands, between 1,800 and ...

, Vitex humbertii,

Faurea forficuliflora ''Faurea'' is a genus containing 16 species of flowering plants in the protea family which occur in the summer rainfall area of southern Africa, extending to tropical Africa and Madagascar. The name honours South African soldier and botanist Wi ...

Pittosporum ''Pittosporum'' ( or ) is a genus of about 200 species of flowering plants in the family Pittosporaceae. The genus is probably Gondwanan in origin; its present range extends from Australasia, Oceania, eastern Asia and some parts of Africa. ''Cit ...

'' sp., and several species of ''

Weinmannia ''Weinmannia'' is a genus of trees and shrubs in the family Cunoniaceae. It is the largest genus of the family with about 150 species. It is also the most widespread genus, occurring in Central and South America including the Caribbean, Madagas ...

''. Other plants include the arborescent monocots ''

Dracaena reflexa ''Dracaena reflexa'' (commonly called song of India or song of Jamaica) is a tree native to Mozambique, Madagascar, Mauritius, and other nearby islands of the Indian Ocean. It is widely grown as an ornamental plant and houseplant, valued for its ...

'' and '' Pandanus alpestris''.

Lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Impatiens ''Impatiens'' is a genus of more than 1,000 species of flowering plants, widely distributed throughout the Northern Hemisphere and the tropics. Together with the genus '' Hydrocera'' (one species), ''Impatiens'' make up the family Balsaminacea ...

'' inhabit the ground layer. Epiphytic mosses and lichens, along with a few small orchids, grow plentifully on the branches of shrubs and trees. The thickets are home a large number of endemic plants, many of whose closest relatives live in

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

and the highlands of

East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historica ...

. Andringitra alone is home to 150 vascular endemics, including 25 species of

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of floweri ...

. The palm ''

Dypsis acuminum ''Dypsis'' is a genus of flowering plants in the family Arecaceae. They are slender, evergreen palms with yellow flowers carried in panicles amongst the pinnate leaves. Many ''Dypsis'' species have aerial branching (above the main trunk), a rare ...

'' is endemic to the Manongarivo Massif. In much of the ecoregion, secondary grassland, established by regular livestock grazing and burning, has almost entirely replaced the original thicket vegetation. The most common grasses on Ankaratra's secondary grasslands are '' Pentameris natalensis, P. humbertii, Andropogon trichozygus, Anthoxanthum madagascariense, Digitaria ankaratrensis, Agrostis elliotii, Merxmuellera macowanii,

Brachypodium perrieri ''Brachypodium'' is a genus of plants in the grass family, widespread across much of Africa, Eurasia, and Latin America. The genus is classified in its own tribe Brachypodieae. Flimsy upright stems form tussocks. Flowers appear in compact s ...

, Poa madecassa, P. ankaratrensis'', and '' Festuca camusiana''. Secondary grassland species are also found in mountain bogs.

Fauna

These high points of Madagascar are home to less diverse animal life than on the lower slopes, but with a high proportion of endemics. The area was not thoroughly researched until the 1990s. There are at least ten species of endemic and near-endemic reptiles including the dwarf gecko '' Lygodactylus arnoulti''.

Threats and preservation

The thickets are vulnerable to fire, and many have been converted to cattle pasture. The widespread conversion of thickets to secondary grasslands may be relatively recent. In 1777 Ankaratra was reported covered with forest. Until the end of the 19th century Andringitra's thickets were a refuge from trouble for local people and their flocks. Ankaratra's and Andringitra's thickets were mostly converted to pasture in the 20th century. Andringitra, Tsaratanana, and Marojejy are all protected areas, and Andringitra's thickets have partially recovered since it was protected. 32.1% of the ecoregion is in protected areas. Protected areas include

Marojejy National Park Marojejy National Park () is a national park in the Sava region of northeastern Madagascar. It covers and is centered on the Marojejy Massif, a mountain chain that rises to an elevation of . Access to the area around the massif was restricted t ...

, Tsaratanana Strict Nature Reserve,

Andringitra National Park Andringitra National Park is a national park in the Haute Matsiatra region of Madagascar, south of Ambalavao. The park was established in 1999 and is managed by the Madagascar National Parks Association. It was inscribed in the World Heritage Site ...

, and Rainforests of the Atsinanana

World Heritage Site A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for ...

References

External links