8/18/2023 0 Comments North of ascension island![]() The lowlands would have been very bare and rocky. Several plant species had also arrived, probably from Africa, and these were mostly restricted to the rocky lowlands. Current knowledge and early records indicate there were at least 6 endemic species of ferns, two grasses and two small shrubs. Subsequent introductions have continued to modify the landscape of the lowland areas.įrom early accounts, it appears that the island was a very barren place, with most of the vegetation restricted to Green Mountain. Goats, rabbits, sheep and donkeys also became established, with the result that the endemic flora was all but eradicated and replaced by a patchwork of vigorous, highly invasive species. Over the next few years, seed from many different tropical plant species were sent out from RBG Kew. In 1843, the eminent botanist Joseph Hooker visited the island and proposed that plantations of large trees should be established on Green Mountain to intercept humid air and increase rainfall, and that the lower slopes should also be 'greened' in order to prevent erosion. Therefore, very few plant species have managed to colonize naturally, and even fewer have evolved into distinct species from their mainland relatives. ![]() In evolutionary terms its ecology is still in the early stages of development. Vegetation and Plant SpeciesĪscension is both very young and extremely isolated. For most of the year, the lowlands are therefore arid and desert-like. As little as 130mm falls in the lowlands, mostly in torrential downpours between March and May. Green Mountain receives 680mm of rain annually, and often accumulates cloud and mist. The temperature is remarkably constant, ranging from a daytime average of 27º C at sea level in September to 30º C in January. There are virtually no sources of fresh water except for where moisture seeps through rocks on the upper slopes. The plain is dotted with at least 22 volcanic cones formed from rock particles ejected from secondary vents. ![]() Younger, red basaltic rocks cover most of the west, forming a stark lowland plain permeated by jagged black lava flows. Pale trachyte types predominate in the east, and form the dome of Green Mountain, the highest point on the island at 859 metres. Ascension's volcanic past has produced a complex of rocks. There has been no recent volcanic activity, although some of the youngest lava flows may be less than 1000 years old. Situated 7º South of the equator and 1500 km from the coast of west Africa, the Island of Ascension was born circa one million years ago. ![]()
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