Now, I’d be very surprised if you’re male and you know what the term “fairy circle” refers to. You see, when we were little girls, fairy circles were the places where fairies gathered. They were barren circles either surrounded by mushrooms of patches in grass. Honestly, I never knew they were actually an African thing.

But when Stephan Getzin, an ecologist at the Helmholtz Center for Environmental Research in Leipzig opened an email one day back in 2014, his heart began to beat a little faster. Attached was an aerial photograph of these fairy circles in the outback:

Normally, the photos that Stephan receives are of long strips of arid grassland stretching from southern Angola to northern South Africa (I could show him some in my garden, too).

Since the 1970’s scientists have been interested in the circles, but have been unable to agree on what causes the patterns to form. There are two predominant teams: Team Termite and Team Water Competition.

 Dr. Getzin, like others on team water competition, explains the circles through pattern-formation theory, a model for understanding the way nature organises itself. The theory was first developed not by biologists, but by the mathematician Alan Turing. In the 1990s, ecologists and physicists realised it could be tweaked to explain some vegetation patterns as well. In harsh habitats where plants compete for nutrients and water, the new theory predicts that, as weaker plants die and stronger ones grow larger, vegetation will self-organise into patterns ranging from gaps to spots to labyrinths.

African Fairy Circles:

In the case of African fairy circles, the bare patches act as troughs, storing moisture from rare rainfalls for several months, lasting into the dry season. Tall grasses on the edge of the circles tap into the water with their roots and also suck it up with the help of water diffusion through the sandy soil.

Australian Fairy Circles:

Although similar in appearance, Australian fairy circles turn out to behave differently, Dr. Getzin and his colleagues have found. The soil where they form is loamy, not sandy as in Africa, they say. And rather than form a water trough, Aussie circles feature a very hard surface of dry, nearly impenetrable clay, which can reach up to a scalding 167 degrees during the day. Despite the differences, though, they believe the fairy circles’ function remains the same. When the researchers poured water into the circles in a simple irrigation experiment, it flowed to the edges, reaching the bushy grass that grew there.

While Team Termite is still unconvinced, arguing that the Australian outback fairy circle is not in the same league as the southern African fairy circle, I just think they might be a bit touchy now that they have been proven wrong. Anyway, read their arguments HERE.

Personally, I just think the fairies got over our African politics and what they are doing to the land and have immigrated to Australia to find safety in the outback (terrible choice, though).

[source: nytimes]