Madagascar spiny forests | |
---|---|
Ecology | |
Realm | Afrotropical |
Biome | Deserts and xeric shrublands |
Borders | |
Geography | |
Area | 43,400 km2 (16,800 sq mi) |
Country | Madagascar |
Elevation | 55–200 metres (180–656 ft) |
Coordinates | 24°54′S44°12′E / 24.900°S 44.200°E |
Geology | Limestone and red sand |
Climate type | Hot desert climate (BWh) |
Soil types | sandy |
Conservation | |
Conservation status | critical/endangered |
Global 200 | yes |
Protected | 8.31% [1] |
The Madagascar spiny forests (also known as the Madagascar spiny thickets) is an ecoregion in the southwest of Madagascar. The vegetation type is found on poor substrates with low, erratic winter rainfall. The ecoregion contains an outstanding proportion of endemic plant species and is listed as one of the 200 most important ecological regions in the world; one of the Global 200.
This is the area with the highest level of plant endemism in Madagascar, with 48% of the genera and 95% of the species endemic. [2] Many constituent plants show extreme adaptations to drought. Spiny plants of the endemic subfamily Didiereoideae form a conspicuous component, especially towards the east. They are woody but distantly related to the cacti. The remaining component of the forests is dominated by members of the plant families Burseraceae, Euphorbiaceae, Anacardiaceae and Fabaceae, all of which have representatives elsewhere. [3]
Notable inhabitants of the spiny thickets include the spider tortoise ( Pyxis arachnoides ) and the radiated tortoise ( Astrochelys radiata ), the gecko Ebenavia maintimainty , several lemurs including Verreaux's sifaka, Grandidier's mongoose, and eight endemic birds. [3]
8.31% of the ecoregion is in protected areas. [1] including Tsimanampetsotsa National Park, Berenty Reserve, Beza Mahafaly Reserve, and Cap Sainte Marie Special Reserve. Andohahela National Park offers limited protection through its 'parcel 3' section. Elsewhere the spiny forest habitat is under pressure from human exploitation. The main impacting activities are burning for conversion to grazing land, harvesting for charcoal and firewood, and logging for construction. [3] The Arboretum d'Antsokay is a botanical garden near Toliara dedicated to preserving the flora of the spiny forest. [4]
As shown on the map on the right, Madagascar can be divided into four climatic ecoregions with four forest types: the moist forest in the East (green), the dry forest in the West (orange), the spiny forest in the South (red), and the mangrove forest on the West coast (blue). Ecoregions were defined following climatic [6] and vegetation criteria. [7] The dark grey areas represent the remaining natural forest cover for the year 2014. Forest types are defined on the basis of their belonging to one of the four ecoregions. [5]
The ecoregions of Madagascar, as defined by the World Wildlife Fund, include seven terrestrial, five freshwater, and two marine ecoregions. Madagascar's diverse natural habitats harbour a rich fauna and flora with high levels of endemism, but most ecoregions suffer from habitat loss.
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 original habitats have been lost due to human pressure.
The Madagascar ericoid thickets is a montane shrubland ecoregion, found at higher altitudes on Madagascar's four major mountains.
The Maputaland-Pondoland bushland and thickets is one of the ecoregions of South Africa. It consists of the montane shrubland biome.
The Meghalaya subtropical forests is an ecoregion of Northeast India. The ecoregion covers an area of 41,700 square kilometers (16,100 sq mi), and despite its name, comprise not only the state of Meghalaya, but also parts of southern Assam, and a tiny bit of Nagaland around Dimapur and adjacent Bangladesh. It also contains many other habitats than subtropical forests, but the montane subtropical forests found in Meghalaya is an important biome, and was once much more widespread in the region, and for these reasons chosen as the most suitable name. The scientific designation is IM0126.
The Deccan thorn scrub forests are a xeric shrubland ecoregion of south India and northern Sri Lanka. Historically this area was covered by tropical dry deciduous forest, but this only remains in isolated fragments. The vegetation now consists of mainly of southern tropical thorn scrub type forests. These consist of open woodland with thorny trees with short trunks and low, branching crowns; spiny and xerophytic shrubs; and dry grassland. This is the habitat of the great Indian bustard and blackbuck, though these and other animals are declining in numbers; this area was at one time home to large numbers of elephants and tigers. Almost 350 species of bird have been recorded here. The remaining natural habitat is threatened by overgrazing and invasive weeds, but there are a number of small protected areas which provide a haven for the wildlife. Trees in these forests have adapted to not require much water.
The Madagascar dry deciduous forests represent a tropical dry forest ecoregion situated in the western and northern part of Madagascar. The area has high numbers of endemic plant and animal species but has suffered large-scale clearance for agriculture. They are among the world's richest and most distinctive dry forests and included in the Global 200 ecoregions by the World Wide Fund. The area is also home to distinctive limestone karst formations known as tsingy, including the World Heritage Site of Bemaraha.
The national parks of Madagascar include all officially recognized protected areas as of 2015. The protected areas network of Madagascar is managed by the Madagascar National Parks Association (PNM-ANGAP). The network includes three types of protected areas: Strict Nature Reserves, National Parks and Wildlife Reserves. At the 2003 IUCN World Parks Congress in Durban, the Malagasy President, Marc Ravalomanana, announced an initiative to more than triple the area under protection from approximately 17,000 km2 (6,600 sq mi) to over 60,000 km2 (23,000 sq mi). This "Durban Vision", as it has been dubbed, involved broadening the definition of protected areas in the country and legislation has been passed to allow the creation of four new categories of protected area: Natural Parks, Natural Monuments, Protected Landscapes, and Natural Resource Reserves. As well as allowing these new objectives for protected areas management, the new legislation also provided for entities other than PNM-ANGAP to manage protected areas, such as government ministries, community associations, NGOs and other civil society organizations, and the private sector.
The Succulent Karoo is an ecoregion defined by the World Wide Fund for Nature to include regions of desert in South Africa and Namibia, and a biodiversity hotspot. The geographic area chosen by the WWF for what they call 'Succulent Karoo' does not correspond to the actual Karoo.
Warren, also known as Karri Forest Region and the Jarrah-Karri forest and shrublands ecoregion, is a biogeographic region in southern Western Australia. Located in the southwest corner of Western Australia between Cape Naturaliste and Albany, it is bordered to the north and east by the Jarrah Forest region. Its defining characteristic is an extensive tall forest of Eucalyptus diversicolor (karri). This occurs on dissected, hilly ground, with a moderately wet climate. Karri is a valuable timber and much of the karri forest has been logged over, but less than a third has been cleared for agriculture. Recognised as a region under the Interim Biogeographic Regionalisation for Australia (IBRA), and as a terrestrial ecoregion by the World Wide Fund for Nature, it was first defined by Ludwig Diels in 1906.
Tsimanampetsotsa National Park also spelt Tsimanampetsotse, and known as Tsimanampetsotsa Nature Reserve is a 432 km2 national park on the south-west coast of Madagascar in the region Atsimo-Andrefana. The park is 90 kilometres (56 mi) south of Toliara and 950 kilometres (590 mi) south of the capital, Antananarivo. Route Nationales (RN) 10 to Faux Cap passes the park and the nearest airport is at Toliara. The national park contains and is named after Lake Tsimanampetsotsa.
The Southern Zanzibar–Inhambane coastal forest mosaic, also known as the Southern Swahili coastal forests and woodlands, is a tropical moist broadleaf forest ecoregion of eastern Africa. It is a southern variation of Northern Zanzibar-Inhambane coastal forest mosaic. The ecoregion supports habitats of forest, savanna and swamps. The southern portion of the ecoregion is not as well studied due to the 1977-1992 civil war in Mozambique.
Deforestation in Madagascar is an ongoing environmental issue. Deforestation creates agricultural or pastoral land but can also result in desertification, water resource degradation, biodiversity erosion and habitat loss, and soil loss.
The East African montane moorlands is a montane grasslands and shrublands ecoregion which occupies several high mountain peaks in Kenya, South Sudan, Tanzania, and Uganda.
The flora of Madagascar consists of more than 12,000 species of plants, as well as a poorly known number of fungi and algae. Around 83% of Madagascar's vascular plants are found only on the island. These endemics include five plant families, 85% of the over 900 orchid species, around 200 species of palms, and such emblematic species as the traveller's tree, six species of baobab and the Madagascar periwinkle. The high degree of endemism is due to Madagascar's long isolation following its separation from the African and Indian landmasses in the Mesozoic, 150–160 and 84–91 million years ago, respectively. However, few plant lineages remain from the ancient Gondwanan flora; most extant plant groups immigrated via across-ocean dispersal well after continental break-up.
The Ethiopian montane forests is a tropical moist broadleaf forest ecoregion in Ethiopia. It covers the southwestern and southeastern portions of the Ethiopian Highlands. The ecoregion includes distinctive Afromontane evergreen forests. The ecoregion's biodiversity is threatened by deforestation, conversion to agriculture, and overgrazing.
The southern Congolian forest–savanna mosaic is an ecoregion that covers a large area of the southern Democratic Republic of the Congo and northeastern Angola. Its rich blend of habitats provides key insights into the biogeography of central Africa with the extensive climatic variation that it has been experiencing for the last 10 million years. The human population is not high.
The Madagascar succulent woodlands are a xeric shrublands ecoregion in southwestern and central western Madagascar. Native plants survive in the arid climate and long dry season with adaptations like succulent leaves, water storing trunks, photosynthetic stems, and dropping leaves during the dry season. The ecoregion is threatened by various human activities.
Arboretum d'Antsokay or Antsokay Arboretum is a botanical garden near the city of Toliara in Madagascar. About 900 plant species grow in the Arboretum, 90% of these endemic to Madagascar, 80% of them considered to have medicinal value and many threatened with extinction. Lonely Planet and Rough Guides both list the Arboretum as the top attraction in Toliara.
The Zambezian region is a large biogeographical region in Africa. The Zambezian region includes woodlands, savannas, grasslands, and thickets, extending from east to west in a broad belt across the continent. The Zambezian region lies south of the rainforests of the Guineo-Congolian region. The Zambezian region is bounded by deserts and xeric shrublands on the southwest, the Highveld grasslands of South Africa to the south, and the subtropical Maputaland forests on the southeast.