Flora The tropical and insular flora of Réunion Island is characterized by its diversity, a very high rate of
endemism, and a very specific structure. The flora of Réunion presents a great diversity of natural environments and species (up to 40 tree species/ha, compared to a temperate forest, which has an average of 5/ha). This diversity is even more remarkable, but fragile, as it differs according to the
environment (coastal, low, medium, and high mountain). Réunion has a very high rate of
endemic species, with more than 850 native plants (of natural origin and present before the arrival of humans), of which 232 are endemic to the Réunion (only present on the island), as well as numerous species endemic to the
Mascarene archipelago. Finally, the flora of Réunion is distinguished from that of equatorial tropical forests by the low height and density of the canopy, probably due to adaptation to cyclones, and by a very specific vegetation, in particular a strong presence of epiphytic plants (growing on other plants), such as
orchids,
bromeliads and cacti, but also ferns,
lichens, and
mosses.
Wildlife Like its prodigious floral diversity, Réunion is home to a variety of birds such as the
white-tailed tropicbird (). Many of these bird species are endemic to the island, such as the
Réunion harrier and
Réunion cuckooshrike. Its largest land animal is the
panther chameleon,
Furcifer pardalis. Much of the west coast is ringed by coral reefs which harbour, among other animals,
sea urchins,
conger eels, and
parrot fish.
Sea turtles and dolphins also inhabit the coastal waters. Humpback whales migrate north to the island from the Antarctic waters annually during the Southern Hemisphere winter (June–September) to breed and feed, and can be routinely observed from the shores of Réunion during this season. Beekeepers began importing
European honey bees during the late 19th century, which in turn have bred with the endemic
Apis mellifera unicolor subspecies, which originated from
Madagascar. 97% of the honey bees on the island are descended from
A. m. unicolor; however, their DNA only accounts for 53% of the genetic mixture. In an attempt to prevent the spread of diseases a bee importation ban was imposed in 1982, however in 2017 one or two Varroa destructor mites were brought into the island when a Queen bee was smuggled in by a beekeeper, within 4.5 months the mites had spread throughout the island, causing an increase of annual deaths of colonies from 0.6% to 64%, after initially reaching 85%. At least 19 species formerly
endemic to Réunion have become
extinct following human colonisation. For example, the
Réunion giant tortoise became extinct after being slaughtered in vast numbers by sailors and settlers of the island. File:FurciferPardalisMale.JPG|A
panther chameleon File:Pomacanthus imperator juvénile.JPG|A juvenile
emperor angelfish File:Idole des Maures (Zanclus cornutus).jpg|A
moorish idol File:White-tailed tropicbird.jpg|A
white-tailed tropicbird File:Eretmochelys imbricata 01.jpg|A
hawksbill sea turtle File:Humpback whale bis.jpeg|A
humpback whale off
St-Gilles Marine biodiversity Despite the small area of coral reefs, the marine
biodiversity of Réunion is comparable to that of other islands in the area, which has earned the
Mascarene archipelago its inclusion among the top ten global biodiversity "hotspots". Réunion's coral reefs, both flat and barrier, are dominated mainly by fast-growing branching coral species of the genus Acropora (family Acroporidae), which provide shelter and food for many tropical species. Recent scientific research in Réunion Island indicates that there are more than 190 species of corals, more than 1,300 species of mollusks, more than 500 species of crustaceans, more than 130 species of echinoderms and more than 1,000 species of fish. Réunion's deeper waters are home to dolphins, killer whales, humpback whales, blue sharks, and a variety of shark species, including whale sharks, coral sharks, bull sharks, tiger sharks, blacktip sharks, and great white sharks. Several species of sea turtles live and breed here. Between 2010 and 2017, 23 shark attacks occurred in the waters of Réunion, of which nine were fatal. In July 2013, the
Prefect of Réunion Michel Lalande announced a ban on swimming, surfing, and bodyboarding off more than half of the coast. Lalande also said 45
bull sharks and 45
tiger sharks would be
culled, in addition to the 20 already killed as part of scientific research into the illness
ciguatera. Migrations of
humpback whales contributed to a boom of
whale watching industries on Réunion, and watching rules have been governed by the
OMAR (Observatoire Marin de la Réunion) and
Globice (Groupe local d'observation et d'identification des cétacés).
Coral reef Because the island is relatively young (3 million years old), the
coral formations (8,000 years old) are not well developed and occupy a small area compared to older islands, mostly in the form of fringing reefs. These lagoons, which form a discontinuous reef belt long (i.e. 12% of the island's coastline) with a total area of , are located on the west and southwest coast of the island. The most important are those of L'Ermitage (St-Gilles), St-Leu, L'Étang-Salé, and St-Pierre.
Management Since 2010, Réunion is home to a
UNESCO World Heritage Site that covers about 40% of the island's area and coincides with the central zone of the La
Réunion National Park. The island is part of the
Mascarene forests terrestrial ecoregion.
Gardening and Bourbon roses The first members of the
"Bourbon" group of garden roses originated on this island (then still Isle Bourbon, hence the name) from a spontaneous
hybridisation between
Damask roses and
Rosa chinensis, which had been brought there by the colonists. The first Bourbon roses were discovered on the island in 1817.
Threats to the environment Among coastal
ecosystems, coral reefs are among the richest in
biodiversity, but they are also the most fragile. Nearly one-third of fish
species were already considered threatened or vulnerable in 2009, with coral degradation in many places. The causes of this state of affairs are pollution,
overfishing, and poaching, as well as anthropogenic pressure, especially linked to the densification of urbanization in coastal areas and the discharge of sewage. 15 species living on Réunion were included in the Red List published by the
International Union for Conservation of Nature (IUCN). == Demographics ==