Archaeology
THE widespread claim that the ancient people of Easter Island underwent a societal collapse due to overexploitation of natural resources has been thrown into fresh doubt. Instead, a small and stable population lived sustainably for centuries before the arrival of Europeans, a new analysis of historical farming practices suggests.
Famous for its towering stone statues, Easter Island – also known as Rapa Nui – lies in the Pacific Ocean and is thought to have been inhabited by Polynesians since around AD 1200. At that time, its 164 square kilometres were covered in palm forests, but these were destroyed quickly, probably by a combination of overharvesting and rats eating fruit and blooms.
According to a popular narrative, the unsustainable use of resources led to runaway population growth and a subsequent collapse before Europeans arrived in 1722.
The islanders mainly supported themselves through rock gardening, a form of agriculture that has been widely practised in places where soils are poor or the climate harsh. Stones are scattered around fields to create microhabitats and windbreaks, preserve moisture and supply minerals.
Previous studies have suggested that as much as 21 square kilometres of Rapa Nui was covered in rock gardens, supporting a population of up to 16,000 people.
4000 people could have been fed by agriculture on Easter Island
To find out more, Carl Lipo at Binghamton University in New York and his colleagues used satellite imagery combined with machine-learning models trained with ground surveys to generate an island-wide estimate of rock gardening sites.
This revealed that the maximum area of the stone gardens was only 0.76 square kilometres. The researchers estimate that such a system would have been able to support about 4000 people – roughly the po
