Fred Pearce, author of The Land Grabbers: The New Fight over Who Owns the Earth, details, ‘I was standing on the summit of an extinct volcano in the centre of one of the most remote islands on the planet: Ascension Island in the tropical South Atlantic. Midway between Brazil and Africa, Ascension is a thousand miles from the nearest speck of land. Below me was a harsh treeless moonscape of volcanic clinker, baking in the sun. But in the cool mountain air, 800 meters up, I was surrounded by lush greenery and a light mist from a cloud settled over the mountaintop. They call it Green Mountain. But the greenery is new. My guide, the island’s conservation development officer, Stedson Stroud, peered around us and smiled. “Nothing you see here is native,” he said. “Except for a few ferns, everything has been introduced in the past 200 years.”’
Everything on Green Mountain, from the Chinese ginger to the guava from Brazil, was introduced by the British Navy during the early- and mid-19th century, along with rabbits, cats, donkeys, hedgehogs, mynah birds, bees, and much else. The entirely man-made forest is the first and only of its kind — a functioning ecosystem in which a ragbag of species shipped in from all over the world thrive as if they had been together for millennia. While many environmental wellness experts hail Green Mountain as the icon for a fundamental reassessment of many nostrums of both environmentalist and ecological science, the artificial woodland is also creating controversy among ecologists. Is it a beacon for re-greening the planet or a biological abomination?
David Wilkinson of Liverpool John Moores University says that the island has about 300 introduced species of plants to add to its 25 native species, many of which are spreading. From about 660 metres and above, Green Mountain is completely vegetated with coffee bushes, vines, monkey puzzle trees, jacaranda, juniper, bananas, buddleia, Japanese cherry trees, palm trees, clerodendrum, green aloe and the pretty pink flowers of the Madagascan periwinkles. Even though rainfall has declined in the lowlands around, the vegetation captures more cloud moisture. However, Pearce notes, ‘The invasion has been double-edged. The invaders have damaged some of the handful of endemic species that had found a foothold on the island during its million-year. Three of the endemic ferns are believed now extinct.’
Nonetheless, Pearce recalls, ‘As we stood on the mountain, gazing south over an abandoned NASA tracking station, Stroud pointed out below us the spot where, in 2009, he rediscovered on a cliff face a single specimen of a species believed lost, Anogramma ascensionis. Now it is being propagated in the UK ready for a reintroduction. In fact, many of the endemics seem to get on remarkably well with the motley collection of invaders, says Stroud. The ferns that once clung to the bare mountainside now prosper on the branches of introduced trees like bamboo. Stroud showed me ferns that he believes now thrive only on the mosses that grow on such branches.’
Pearce laments that a blindness in research may mean we learn nothing from Green Mountain. ‘The British government’s environmental policy for the island is the “control and eradication of invasive species” in order to “ensure the protection and restoration of key habitats,”’ says Pearce. ‘But the policy has nothing to say about the protection of — or even ecological research into — the extraordinary novel ecosystem in their midst on which the indigenous species often depend. That is a shame. For, according to an increasing number of ecologists, the unique ecosystem on Green Mountain may hold important lessons about how ecosystems around the world function…The mountain’s ecosystem calls into question a series of widely held assumptions about how complex, biodiverse ecosystems evolve — or indeed whether they evolve at all.’
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