It created the first global atlas of “fairy circles,” those mysterious circular structures bounded by a ring of tall grass that typically form in dry terrain and last for more than 20 years.
These formations, previously known only in Namibia and Western Australia, actually occur in more than 260 locations across three continents, such as the Sahel, Western Sahara, the Horn of Africa, Madagascar, Southwest Asia and Central Australia. This is suggested by satellite images analyzed using artificial intelligence models by a Spanish team led by the University of Alicante. The results are published in the Journal of the American Academy of Sciences, PNAS.
“Our study – explains one of the authors, Manuel Delgado Baquerizo – provides evidence that fairy circles are much more common than previously thought, which has allowed us, for the first time, to understand at a global level the factors that influence their distribution” . From the data collected, it appears that the presence of fairy circles is linked to a number of soil and climate characteristics, such as low nitrogen levels and an average rainfall of less than 200 millimeters per year.
“This study took into account several variables that had not been taken into account before, such as albedo and the condition of the aquifers,” emphasizes colleague Jaime Martínez-Valderrama. “This is particularly relevant as massive groundwater exploitation in arid areas of the world, including deserts, could disrupt these formations.”
The researchers hope that the Atlas of Fairy Circles and its associated database will be helpful in understanding whether this particular vegetation arrangement provides greater resilience to climate change and whether these circles can be considered indicators of ecosystem health.
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