The so-called ‘fairy circles’ of the Namibian desert (Africa) are barren areas that are curiously surrounded by perennial vegetation and that can reach up to 35 meters in width. But what is the origin of these strange formations?
The pattern of these circles is characterized by their regular spacing and hexagonal distribution. Despite the fact that regular vegetation patterns are frequent in nature, the scientific community does not agree on the motivation behind them. The truth is that there are several hypotheses about them.
The first one says that the origin must be sought in that plants help the growth of the vegetation closest to them and, on the contrary, compete with the most distant species, hence the curious patterns observed in satellite images. The second hypothesis suggests that termites, ants or rodents are responsible.
Well, according to the study carried out by the department of Ecology and Evolutionary Biology at Princeton University (USA) and published in the journal Nature, the two hypotheses are valid. By reconciling both perspectives through simulation models, they found that both sand termites ( Psammotermes allocerus ) and vegetation converge in the emergence of the famous fairy circles; that is, the two make up a joint cause of these regular and self-organizing patterns. The research was validated thanks to field data from four continents: Africa, North America, South America and Australia.
Termites (according to a study published in Science in 2013) devour vegetation that follows intermittent desert rains, which is why circular wastelands appear. But, due to the rapidity of filtration and the lack of evapotranspiration, they also retain water . The conclusion of all this process is the formation of circles of perennial vegetation, the ‘fairy circles’.
