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Next to nothing here about the political status of these islands - which are independent under the name of Mauritius, which are still overseas territories etc. Grunners (talk) 00:01, 12 February 2008 (UTC)
Island Arc of Archipelago?
Poorly written section removed
The following material, largely unsourced and poorly written is removed here pending extensive revision or trimming:
The country are large islands and volcano archipelago renmants into the Indic Ocean area. The terrain includes a variety of reefs, atolls, small islands, and a variety of topographical and edaphic regions on the largest island,which promoted the development of an unusually biodiversity. The region's climate is oceanic and tropical. The Mascarenes consist of three main islands, La Reunion, Mauritius and Rodrigues. These islands differ in size, elevation profile, age, distance to the next larger land mass (Madagascar) and biodiversity. The Mascarenes are particularly rich in plants species, with about 1,300 vascular plants, of which 585 are endemics. Some species endemic in Reunion island are named with latin names related to "Île Bourbon", the previous name of the island. The islands are home to many endemic plants and animals 150 in Maurituis and 42 in Reunion. There are many flora and fauna introduced species. Most of the Mascarene flora and fauna is thought to be derived originally from Madagascar and Africa as Ocotea, Erythrina, Monimiaceae, and Sideroxylon trees. The islands have never been connected to the mainland, so the flora and fauna of the Mascarenes arrived from over the sea. Prehistoric islands of the Mascarene Plateau, now disappeared under the sea, may have served as 'stepping stones' which allowed species to island-hop from the Seychelles or Madagascar. The Mascarenes are home to one endemic family of flowering plants, Dombeyoideae, and genus Psiloxylon, which has only one species, Psiloxylon mauritianum. Five Hyophorbe species as Bottle Palm tree (Hyophorbe lagenicaulis), and Spindle Palm Tree (Hyophorbe verschaffeltii) and some Ocotea as Ocotea lancilimba and Ocotea obtusata. Ferns form an important component in the diverse biotas of the islands, especially in tropical forest. Most ferns disperse easily via their spores, allowing frequent colonization from Madagascar but also exchange among the Mascarene islands. Until Europeans first settled the islands in the sixteenth century, no peoples were known to exist in the Mascarenes, so much of the island's wildlife, which would have gone extinct much earlier had any native people lived there, were still flourishing during the early days of settling.
The Mascarene islands form a distinct ecoregion, known as the Mascarene forests. Despite of this, descriptions of the vegetation zones, the islands account ﬁve natural plant formations arranged in broad according to moisture and altitudinal zone.
The islands were formerly covered in tropical moist broadleaf forest and harbored a diverse range of forest types, the freshwater biota is highly distinctive. Near the seacoast were coastal wetlands and swamp forests, transitioning to rain forest to windward and lowland dry forest to Leeward Islands, palm savannas, montane deciduous forests, and montane heathlands on the highest peaks of Réunion.
The dry lowland forests present from sea level to 200 m elevation is in areas with less than 1000 mm average annual rainfall. These dry lowland forests are dominated by palms as Latania spp., and Dictyosperma album), the screw-pines (Pandanus spp), and trees such as Terminalia bentzoe (Combretaceae).
Semi-dry sclerophyllous forests occurred between coastal areas and 360 m on all sides of Mauritius and Rodrigues, but were restricted to 200–750 m elevation on the western slopes of Réunion, where they still exists in small forest remnants. This ecosystem has an average annual rainfall of 1000–1500 mm. The characteristic species are ebonies as (Diospyros spp., and Ebenaceae genera. Other tree species are occurring such as Pleurostylia spp. (Celastraceae), Foetidia spp. (Lecythidaceae), Olea europea subsp. africana (Oleaceae), Cossinia pinnata (Sapindaceae), Dombeya spp. (Sterculiaceae), and a variety of Sapotaceae species (Sideroxylon boutonianum Sideroxylon borbonicum spp. and Mimusops. The ecosystem is also home to several spectacular endemic species of Hibiscus (Malvaceae) Zanthoxylum spp. (Rutaceae), Obetia ﬁcifolia (Urticaceae), and Scolopia heterophylla (Flacourtiaceae).
The Lowland rainforests are characterized by dense evergreen forests, with a canopy exceeding 30 meters. With an average annual rainfall of 1500–6000 mm, occur on Mauritius island above 360 m and all over the eastern lowlands from the coast to 800–900 m and, on the western side. On Réunion island the Lowland rainforests is present from 750 to 1100 m. These forests have a canopy of tall trees up to 30 m high and represent the more diversified plant communities of the Mascarene Islands. Characteristic plants include trees in the plant family Sapotaceae e.g. Mimusops spp. Labourdonnaisia spp., Hernandiaceae Hernandia mascarenensis, Clusiaceae Calophyllum spp., and Myrtaceae Syzygium spp., Eugenia spp., Sideroxylon spp., Monimiastrum spp.; shrubs in the plant family Rubiaceae (Gaertnera spp., Chassalia spp., Bertiera spp., Coffea spp.); bamboos as Nastus borbonicas, numerous species of orchids (e.g., Angraecum spp., Bulbophyllum spp.) and ferns e.g., Asplenium spp., Hymenophyllum spp., Trichomanes spp., Elaphoglossum spp., Marattia fraxinea.
The cloud forests, a dense type of hygrophilous rainforest, occur on Réunion between 800 and 1900 m on eastern slopes with an average annual rainfall 2000–10,000 mm, and between 1100 to 2000 m on western slopes with an average annual rainfall 2000–3000 mm and are also restricted to a small area of Mauritius around the montane area "Montagne Cocotte" above 750 m on Mauritius with an average annual rainfall 4500–5500 mm. These type of forests is present on both islands with a canopy of 6 to 10 m high. They are rich in epiphytes (orchids, ferns, mosses, lichens), emergent tree ferns (Cyathea spp.), and, originally, palms (Acanthophoenix rubra), but these now survive only in areas of Réunion where poaching has not wiped them out. Untransformed cloud forests still cover large areas on Réunion with 44,000 ha in 2005. These forests are characterized by trees such as Dombeya spp., on the Réunion island only, and species in the plant family Monimiaceae (Monimia spp., Tambourissa spp.) as canopy species, with small trees and shrubs sucth as Psiadia spp. (Asteraceae) and Melicope spp. (Rutaceae) in the understory. They also include large areas of three monodominant plant communities, forests with Acacia heterophylla (Fabaceae) as canopy species that are very similar to Acacia koa forests in Hawaii, thickets dominated by Erica reunionensis (Ericaceae), or hyperhumid screw-pine forest (Pandanus montanus).
The subalpine scrub with an average annual rainfall 2000–6000 mm is above the tree line to 1800–2000 m, at elevations where frosts occur regularly in winter, dominated by shrubs in the plant families of Ericaceae (Erica spp.), Asteraceae (Hubertia spp., Psiadia spp., Stoebe passerinoides), and Rhamnaceae (Phylica nitida), with some notable endemic species suchs Heterochaenia rivalsii (Campanulaceae), Eriotrix commersonii (Asteraceae), and Cynoglossum borbonicum (Boraginaceae).
The summits of the volcanoes are covered by large mineral areas with sparse grasslands rich in endemic grasses (Poaceae, e.g., Festuca borbonica, Agrostis salaziensis, Pennisetum caffrum) and orchids (Orchidaceae, e.g., Disa borbonica), ericoid thickets, or thickets of the small tree Sophora denudata (Fabaceae), depending on substrate texture and age.
In the Mascarenes, the angiosperms with 22 species have 21 endemic. The endemic Dombeyoideae from the Mascarenes are polyphyletic and splited into nine clades. Trochetia appears monophyletic and more closely related to Eriolaena and Helmiopsis than to Dombeya. All Dombeya taxa are included in a clade together with Ruizia and Astiria, this means that Dombeya is paraphyletic. In terms of breeding systems the Malagasy Dombeyoideae are hermaphroditic, whereas those of the Mascarenes are considered dioecious. The polyphyly of the Mascarene Dombeyoideae suggests that dioecy has been acquired several times. At least five colonization events from Madagascar to the Mascarene archipelago were produced. The evolutionary history of two lineages of Mascarene Domeyoideae seems to be related to adaption to xeric habitats.
The islands have no native mammals, except for bats as the now extinct Pteropus subniger. Sixteen endemic bird species survive on the islands. Many of the Mascarene birds evolved into flightless forms; the most famous of which was the Dodo of Mauritius, and the Rodrigues Solitaire extinct flightless pigeons. Mauritius, Réunion, and Rodrigues were also once each home to one or more species of giant tortoises, now extinct, which comprised the genus Cylindraspis. There are thirteen living endemic reptile species, including a number of species of day geckoes (genus Phelsuma).
Much of the Mascarenes' native flora and fauna has become endangered or extinct since the human settlement of the islands in the 17th century. Settlers cleared most of the forests for agriculture and grazing, and introduced many exotic species, including pigs, rats, cats, monkeys, and mongooses. As well as the tortoises and the Dodo, thirteen additional species of birds became extinct, including the Rodrigues Solitaire, a flightless pigeon related to the Dodo, and the Réunion Flightless Ibis.
The Tambalacoque (Sideroxylon grandiflorum), often called the dodo tree, is also threatened with extinction, although this is principally as a result of unripened seed destruction by the introduced crab-eating macaque (Macaca fascicularis) rather than any connection to a reliance on the dodo to assist with seed germination after the seeds passed through the extinct bird's digestive tract.
The Mascarene Islands are surrounded by approximately 750 square km of coral reef. Rodrigues has nearly continuous fringing reefs bounding an extensive lagoon with deep channels, whereas Mauritius is surrounded by a discontinuous fringing reef and a small barrier reef. In contrast, Réunion has very short stretches of narrow fringing reefs along the western and southwestern coasts only. The islets of the Cargados Carajos Shoals, which have a very depauperate terrestrial biota owing to being so low-lying and swamped during cyclones, are bound to the east by an extensive arc of fringing reef, which accounts for ∼30% of the reefs of the Mascarene Islands. Lagoon reefs and reef ﬂats are dominated by scleractinian corals such as branching and tabular Acropora, Porites massives, foliaceous Montipora and Pavona, and sand consolidated with beds of seagrass such Halophila spp. (Hydrocharitaceae). Among coral reef ﬁ shes, wrasses (Labridae), damselﬁsh (Pomacentridae), carnivorous groupers (Serranidae), and surgeonﬁshes (Acanthuridae) are particularly well represented.