The islands of this group result from volcanic activity associated with the Atlantic Mid-Ocean Ridge.
Saint Helena harbors at least 40 species of plants unknown elsewhere in the world.
As seen in the above photograph from the International Space Station, Saint Helena's rugged topography of sharp peaks and deep ravines is the result of erosion of the volcanic rocks that make up the island.
A climatic gradient related to elevation is also evident - the higher, wetter central portion of the island is covered with green vegetation, whereas the lower coastal areas are drier and hotter with little vegetation cover.
About 14 million years old, St. Helena is the deeply eroded summit of a composite volcano. The resulting topography is quite dramatic. Plugs, domes, and dykes from the volcanoes create striking formations with names such as Lot, Lot's Wife, and the Gates of Chaos.
It was uninhabited when first discovered by the Portuguese João da Nova discovered the island on May 21, 1502; now feast day for St. Helena in the Eastern Church.
It was visited again in 1588 by Captain Thomas Cavendish aboard the HMS Desire and soon became a port of call for ships en route between the East Indies and Europe.
St. Helena’s first inhabitants were employees of the trading companies and English settlers, who also brought slaves from South Asia, the East Indies, and Madagascar. By 1673 nearly half of the island’s inhabitants were slaves, until emancipation was achieved between 1826 and 1836.
St. Helena became famous when Napoleon was exiled to the island in 1815; he died there in 1821.
During the Zulu wars, the island was used again as a place of exile for Zulu warriors. During the Anglo-Boer War in South Africa, several thousand Boer prisoners were confined on the island between 1900 and 1903.
Its importance as a port of call declined after the opening of the Suez Canal in 1869.
St. Helena is a British colony, with its capital and port at Jamestown.
Ecologically, it is included within the St. Helena scrub and woodlands ecoregion.
It is believed that St. Helena once had substantial forests at elevations ranging between 400 and 600 m, primarily composed of gumwood (Commidendrum robustum) with smaller amounts of bastard gumwood (Commidendrum rotundifolium).
Introduced goats between the island’s discovery in 1502 and settlement in 1659 fragmented these forests, though large wooded areas still persisted. Remaining forest was then virtually eradicated during the 18th century through extensive cutting for firewood and the grazing of stock animals.
A small gumwood stand survives at Peak Dale; the remainder of the island is covered by pasture, abandoned flax plantations, replanted woodland, dry rocky lowland, and some semi-natural shrubland vegetation.
Due to St. Helena’s isolation, the island was a refuge for many endemic species. It is believed that many of the island’s native plants are relicts of a primitive flora that was once widespread and that colonized the island as many as 10 million years ago. An example is seen in the tree fern (Dicksonia arborescens), which has been on St. Helena for at least 9 million years but no longer occurs in its likely source area of Africa. This type of relict endemic is frequent on islands, and is an important remnant of biodiversity that has disappeared elsewhere.
The island’s native flora was composed of about 70 species of flowering plants and ferns, 60 of which are endemic in 10 endemic genera. These numbers place St. Helena in the top ranks of islands important for unique worldwide biodiversity. However, St. Helena has suffered severe degradation, and over half of the plants described in 1875 have since disappeared from the island. Currently, the remaining endemic plants are restricted to small remnants of their former habitat in protected spots such as steep cliffs or wastelands.
Quite a few species once thought to be extinct have been rediscovered in recent times, including the local ebony (Trochetiopsis ebenus), St. Helena olive (Nesiota elliptica), false gumwood (Commidendrum spurium) and bastard gumwood (Commidendrum rotundifolium). While native vegetation declined many economically important plants were being introduced, and the total number of plant species present on St. Helena increased significantly. The flora now claims about 320 species, of which approximately 260 are naturalized aliens.
Diana's Peak is a National Park, and wardens work to preserve endemic species such as tree ferns and dogwoods that have been inundated by introduced plants such as the New Zealand flax.
A severe drought occurred in 1984. Water is a scarce resource on St. Helena for humans and nature alike, and drought poses a significant threat to the fragile and isolated ecosystem.
The island is far from being economically self-sufficient and depends largely on funding from the United Kingdom. There has been a push to promote tourism as a source of revenue, though the island has never been accessible by airplane due to its mountainous terrain.
Currently, A British company, the St. Helena Leisure Corporation (SHELCO) has made proposals "to develop communications and tourist amenities on the island by constructing a privately-funded airport, a world-class international quality resort hotel, and a superior 18-hole championship-standard golf course." It appears that the project has strong support from the local community. The proposed airstrip would be leveled near a spot called Prosperous Bay Plain, a 150 hectares (ha) area of semi-desert supporting the native shrub, Suaedia fruticosa, and an endemic annual, Hydrodea cryptantha as well as many endemic invertebrates, some of which are known exclusively from this plain. While Prosperous Bay Plain is also thought to be closer to the endemic wirebird’s original habitat than any other now existing on the island, the bird occurs here in much lower numbers than it does in non-native pasturelands. While not yet accepted, the construction of an airstrip would have many impacts beyond the rock-blasting and cut-and-fill alteration of the Prosperous Bay Plain area.
Geographic Coordinates: 15 57 S, 5 42 W
Area: 122 sq km
Coastline: 60 km
Terrain: rugged, volcanic; small scattered plateaus and plains. The highest point is Mount Actaeon (818 m).
Climate: tropical marine; mild, tempered by trade winds
Dependency status: overseas territory of the UK
Capital: Jamestown - 1,000 (2009)
Legal System: English common law and local statutes
Jamestown, Saint Helena. Source: Andrew Neaum/Wikimedia Commons
People and Society
Population: 7,700 (July 2011 est. for British Overseas Territory of Saint Helena). Includes small populations on Ascension, and Tristan da Cunha islands as well as Saint Helena itself.
Ethnic Groups: African descent 50%, white 25%, Chinese 25%
0-14 years: 17.8% (male 697/female 671)15-64 years: 70% (male 2,731/female 2,656)65 years and over: 12.3% (male 468/female 477) (2011 est.)
Population Growth Rate: 0.377% (2011 est.)
Birthrate: 10.65 births/1,000 population (2011 est.)
Death Rate: 6.88 deaths/1,000 population (July 2011 est.)
Net Migration Rate: 0 migrant(s)/1,000 population (2011 est.)
Life Expectancy at Birth: 78.76 years
Total Fertility Rate: 1.57 children born/woman (2011 est.)
Literacy (age 20 and over can read and write): 98% (1987 est.)
Urbanization: 40% of total population (2010) declining at an annual rate of change of 0.3% (2010-15 est.)
Topographic map of the British island of Saint Helena showing proposed Airport. Source: Wikimedia Commons
Natural Resources: fish, lobster
The economy depends largely on financial assistance from the UK, which amounted to about $27 million in FY06/07 or more than twice the level of annual budgetary revenues.
The local population earns income from fishing, raising livestock, and sales of handicrafts.
Because there are few jobs, 25% of the work force has left to seek employment on Ascension Island, on the Falklands, and in the UK.
GDP: (Purchasing Power Parity): $18 million (1998 est.)
GDP- per capita (PPP): $2,500 (1998 est.)
Agricultural products: coffee, corn, potatoes, vegetables; timber; fish, lobster; livestock
Industries: construction, crafts (furniture, lacework, fancy woodwork), fishing, philatelic sales
Currency: Saint Helenian pounds (SHP)