Pitons, cirques and remparts of Reunion Island, France, World Heritage site
Pitons, cirques and remparts of Reunion Island is a World Heritage Site in the interior of the Island of La Réunion, featuring spectacular volcanic landscapes, luscious rainforests and stunning gorges and waterfalls. The island is made up of two volcanic massifs: the Piton des Neiges, a now dormant volcano which created the island 2.1 million years ago, and the Piton de la Fournaise, an active volcano in the southeast.
La Réunion rises to 3,071m in altitude, and is the youngest of the three Mascarene Islands. The climate is oceanic and subtropical, but the island’s varied topography creates many microclimates and a variety of ecological conditions. The World Heritage Site includes the middle and upper slopes and peaks of the two volcanoes and a linking section between them. The volcanic and erosional topography of the site is striking.
Long linear and curvilinear escarpments known as “remparts” rise to 1,000m in places, surrounding erosional “cirques” in the flanks of the volcanoes, or adjoining the radiating streams. The peak of the Piton des Neiges lies at the centre of three such scarp-rimmed “cirques”: Salazie, Mafate and Cilaos. The Piton de la Fournaise, rising to 2,632 m, is one of the world’s most continuously active volcanoes: it has erupted over 100 times since 1640. The Plaine des Sables, a large area of fine volcanic material, provides a dramatic barren landscape towards the top of the volcano.
The two peaks, with their great variety of rugged terrain of differing heights and aspects, and the visual impact of the escarpments, forested gorges and basins are of stunning beauty.
La Réunion National Park was established in 2007 and comprises 96% of all remaining natural areas of La Réunion. Most of the National Park (c. 90%) is state owned, while the majority of the remainder is under various other forms of communal and public ownership, and a small extension being on private land. The National Park contains two small strict nature reserves: the Saint Philippe-Mare Longue Reserve set up in 1981, covering 68 ha; and the Roche Ecrite Planèze Reserve, covering 3,643 ha, aimed at conserving the Critically Endangered Réunion Cuckoo-shrike (Coracina newtoni).
View photos of the World Heritage site
Size and Location
La Réunion lies 750 km east of Madagascar and 200 km southwest of Mauritius. It is part of the Mascarene Island group in the south-western Indian Ocean. The World Heritage site has an area of 105,838 ha, which represents 42% of the total area of the island. The nominated property is surrounded by a buffer zone of 11,729 ha that includes the lower part of the volcanic cirques.
Flora and Fauna
Like all oceanic islands, La Réunion has a relatively low species richness compared to comparable continental areas, but is typified by a high level of endemism. The steep altitudinal variation of the island supports a series of different habitats ranging from subtropical rainforest moving up into Pandanus thickets, cloud forest and heath on the windward side of the island, and through dry subtropical forest and steppes, the most threatened habitat types on La Réunion, on the leeward side.
La Réunion is considered a global Centre of Plant Diversity, where a third of the vegetation is forest, and it conserves the most extensive and best remnants of the natural vegetation of the Mascarene Islands. Its variety is due to topographic complexity, climatic variation, the abrupt altitudinal gradient and to the island’s oceanic isolation. It hosts 1,712 species of vascular plants. Of the 840 indigenous species, 389 (46.3%) are endemic, 236 being locally and 153 regionally endemic. 8 genera are endemic to Réunion, and 5 more endemic to the Mascarenes. There are also 754 species of mosses.
Although altered by human use, the impact of human activity on the ecosystems of La Réunion is lower than elsewhere in the Mascarenes.
As for most remote islands, the vertebrate fauna is poor, having less than 50 indigenous species. A significant number of these species are known to have become extinct since human settlement began in 1650, including a giant tortoise and the iconic dodo bird. However, the bird population has survived better than on other islands, since monkeys and mongoose were never introduced. Out of the 78 birds, 7 are endemic of the island. Amongst recorded insects, 40% of the beetles and 25% of the 500 spiders are endemic. There are 500 species of butterflies. Out of the existing 54 molluscs, 20 are endemic to La Réunion, and 24 more to the Mascarenes. There are also 21 freshwater fish, 9 freshwater crustaceans and 20 freshwater molluscs all of which are endemic. The World Heritage site protects the areas that are important in sustaining these levels of biodiversity.
In relation to ecosystem processes, it is worth noting that the vast tract of mostly intact forest stretching from sea level at Mare Longue to the summit of the Piton de la Fournaise is an exceptional survival within tropical islands in the Indian Ocean. There is a large number of distinct habitat types, plant succession has been studied in detail, and there are good examples of the ongoing emergence of species.
The greatest threat to the values of the site is the large number of invasive alien species, both animals and plants. They are most intrusive in the semiarid, lowland and mid-level forests, and the invasive plants include some of the most problematic and pervasive known invasive species. Eight alien mammals are also present, including deer, rats, dogs and cats. The extreme pressure from these invasive alien species has completely disrupted ecological processes in many areas of the island, and when natural vegetation disappears due to landslips, lava flows, or other factors, it is mostly replaced by more aggressive exotic species.
Another menace to the unique natural values is posed by urban development and population pressures. The island is heavily populated and population is increasing quickly, especially in the coastal plain. Aside from the cirque areas, most of the interior of the island is however not settled.
Dealing with the threats
A comprehensive strategy to control and eradicate invasive alien species (IAS) was agreed on in 2008. A number of institutions are working on IAS issues and substantial financial resources are allocated to work on this subject. A number of actions have been already successfully implemented, such as the eradication of cats and rats in the Nature Reserve of la Roche Ecrite affecting nesting areas of the La Réunion Cuckoo-shrike, a forest bird endemic of the island.
There are a number of regulations in place to control the impacts resulting from tourism. They are supported by environmental awareness programmes with tourism operators and local communities.
Tourists to La Réunion can choose from a wide variety of outdoor activities: hang-gliding, paragliding, riding, rafting, whitewater kayaking, mountaineering, rock climbing, trekking, camping and picnicking. In 2005 the estimated number of tourists to La Réunion numbered 603,000, many visiting the beaches which are not within the World Heritage site. Sightseeing and trekking in the interior of the island is growing in popularity and there is a road access to viewpoints on the Piton de la Fournaise.