This BioProvince (as defined by Armen Takhtajan) includes the Juan Fernandez Islands, which mainly comprise Alejandro Selkirk (Masafuera), Robinson Crusoe (Masatierra), Santa Clara and the Desventuradas Islands (San Ambrosio and San Felix). They are all of volcanic origin, but their ages vary - Santo Clare is over 5 million years old, Masatierra is roughly 4 million and Masafuera between 1 and 2.4 million. The climate is subtropical and greatly influenced by fluctuations in the flow of the Subantarctic Humbolt current and the southeast trade winds, which create high-winter and low-summer rainfall. However, rainfall levels tend to increase with altitude, and certain lowland areas such as the western side of Masatierra can be very dry. The flora comprises 361 vascular plants including 53 ferns and is characterised by an extremely high level of endemism with one endemic family (Lactoridaceae), many endemic genera including Cuminia (Lamiaceae), Centaurodendron (Asteraceae), Dendroseris (Asteraceae), Juania (Arecaceae), Lactoris (Lactoridaceae), Lycapsus, Megalachne (Poaceae), Nothomyrcia, Nesocaryum, Ochagavia (Bromeliaceae), Pantathera, Podophorus (Poaceae), Robinsonia (Asteraceae), Rhetinodendron, Selkirkia (Boraginaceae), Symphochaeta, Thamnoseris, Thyrosopteris (Dickinsoniaceae) and Yunquea (Asteraceae), and 129 endemic species. In percentage terms, the native flora has 11% endemism at the generic level and 60% at the specific level. An interesting feature of the endemic flora is the high degree of woodiness with 64% of dicots being trees or shrubs. This is thought to reflect the filling of ecological niches by groups not ordinarily disposed to the woody condition as evidenced by the woody Plantago fernandezia.
The following accounts for this BioProvince have been written or will be written with particular reference to endemic and locally important species. Accounts available are displayed in green or yellow. Those displayed in red are either in the pipeline or awaiting expert contributions.
|Endemic Vascular Plant Flora|