April 11, 2018 12:25

Ascension’s Green Mountain | From lookout to ecological experiment

Biological clean slate

When there is one island in the middle of the tropical South Atlantic, with the nearest island 700 miles away, and the nearest mainland 900 miles away, it is inevitable that everything about the place is unique. When Ascension Island first rose from the sea, it was devoid of life, a biological clean slate. Indeed, from that first day, every living thing on the island had to fly, swim, drift, get blown or be carried here.

360° lookout

Elliott’s Path is a circular walk at 2400 feet around the top of Green Mountain, the highest peak on Ascension Island. The path was created as a 360 degree lookout for the Royal Marines in the 19th century. It is an incredible feat of human engineering with tunnels and arches hewn into the volcanic rock. The garrison’s troops were of course not just on the mountain for sightseeing purposes.They were there to keep watch on shipping in the days before radar and the likes.

Most successfull ecological experiments of all time

Under naval occupation, Ascension became an established imperial outpost, and was a rest stop for scientist explorers like Charles Darwin and Joseph Dalton Hooker. It was the botanist Hooker, at the encouragement of Darwin, who would devise a plan that would radically change the island’s habitability in what was one of the most successful ecological experiments of all time.

In 1847, Hooker, with help from his father who directed the Royal Botanical Gardens, Kew, arranged for trees to be shipped to the island. The idea was that the planted trees would capture rain and make the soil fertile, transforming the barren landscape into a lush garden. Year after year, new varieties of trees arrived from botanical gardens in Europe, South Africa, and Argentina. By the late 1870s, the island was home to Norfolk pines, eucalyptus, bamboo, and banana trees.

Cloud forest

The plan worked perfectly. Green Mountain, the highest peak on the island, became a “cloud forest,” characterized by persistent low-level cloud cover. The trees draw moisture from these clouds, enriching the soil and allowing vegetation to thrive. Darwin, Hooker, and the Royal Navy effectively turned Ascension into an island oasis, and in the process became the architects of the very first experiment in terraforming. It stands both as a great early example of bio-engineering and an example of a man-made experiment that has endangered the island’s native and endemic plant species, such as the Ascension island parsley fern, rediscovered in 2009. The fern was sent back to Kew to be propagated and has returned to be planted out.

Artificial ecosystem

While Ascension Island remains relatively unknown, its legacy may eventually prove to be profoundly important to humans’ survival; the success of the island’s artificial ecosystem, which is one of few large-scale planned forests in the world, has given hope to those that believe the colonization of Mars is necessary.

Potable water, or lack thereof, has always been a major issue on Ascension. Here again, at least in the early days, Green Mountain provided. In the late nineteenth century, the hillsides around Breakneck Valley were concreted in places as a water catchment area to collect rainwater. The water eventually piped down to Georgetown in a series of iron pipes (via a 300m tunnel dug in the 1830s), now largely disused though they still supply the Administrator’s residence high up on the mountain. It was the island’s main water supply until the 1960

Stedson Stroud, Conservation Development Officer/National Park Ranger rediscovered extinct parsley fern on Green Mountain

The Red Lion

Jolene Sim, Conservation Officer

View of Wideawake Airport

The Royal Air Force Base (left) and Two Boats Village (right)

Stedson Stroud, Conservation Development Officer/National Park Ranger

The pond was constructed in 1875 and was open and exposed until the bamboo forest was planted in 1877. By the 1880s, Hooker’s “mist-catching trees” had formed a small pond at the mountain’s summit, the island’s first freshwater water body. Today, bamboo trunks form a 40-foot tall wall around the Ascension’s famous Dew Pond.