Scientists believe that an ecological experiment by Charles Darwin and Joseph Hooker might hold the key to the colonisation of Mars.
Ascension was an arid island, buffeted by dry trade winds from southern Africa. Devoid of trees at the time of Darwin and Hooker’s visits, the little rain that did fall quickly evaporated away. Its existence depends entirely on what geologists call the mid-Atlantic ridge. This is a chain of underwater volcanoes formed as the ocean is wrenched apart.
Egged on by Darwin, in 1847 Hooker advised the Royal Navy to set in motion an elaborate plan. With the help of Kew Gardens – where Hooker’s father was director – shipments of trees were to be sent to Ascension.
The idea was breathtakingly simple. Trees would capture more rain, reduce evaporation and create rich, loamy soils. The “cinder” would become a garden.
So, beginning in 1850 and continuing year after year, ships started to come. Each deposited a motley assortment of plants from botanical gardens in Europe, South Africa and Argentina.
Soon, on the highest peak at 859m (2,817ft), great changes were afoot. By the late 1870s, eucalyptus, Norfolk Island pine, bamboo, and banana had all run riot.
Dr Wilkinson describes the vegetation of “Green Mountain” – as the highest peak is now known – as a “cloud forest”. The trees capture sea mist, creating a damp oasis amid the aridity.