Fairy circles are round patches of barren land often surrounded by grass. Various hypotheses have been suggested about what causes them, from gods and spirits to termites, unusual climate conditions, or self-organizing properties of plants. Previously, fairy circles have been spotted in Southern Africa's Namib Desert and the Western Australia outback.
"Aboriginal people illustrated these patterns at least since the 1980s and said they knew of them for generations, probably millennia earlier," says Fiona Walsh, and ethno-ecologist at the University of Western Australia.
And now, researchers using artificial intelligence to analyze satellite imagery have found hundreds of newly-identified fairy circles across 15 countries and three continents—Africa, Australia, and Asia.
The study authors also compiled environmental data where circles were spotted, collecting evidence that might hint at what causes them to form. The researchers determined that fairy circle-like patterns were most likely to occur in very dry, sandy soils that were high-alkaline and low in nitrogen. The scientists also found the fairy circle-like patterns helped stabilize ecosystems, increasing an area's resistance to disturbances such as floods or extreme drought[…]
Many questions about fairy circles have yet to be answered, and the authors of the new study are optimistic that their global atlas will open a new chapter in the study of these peculiar barren spots.
"We hope that the information we publish in the paper can provide scientists around the world with new areas of study that will solve new puzzles in the formation of fairy-circle patterns," [University of Alicante data scientist Emilio] Guirado said.
(Thanks, Chanté McCormick!)