Three main theories to explain the origin of the mysterious "fairy circles" in Namibia, has just been refuted — as finished work of South African researchers. "They are still a mystery," — said Gretel fan Ruoyen, a botanist at the University of Pretoria, who led the study.
Magic circles — it drives completely bare sandy soil with a diameter of two to ten meters. They are found only on the western edge of the coastal Namib Desert, they are hard to miss — nude inside of the perimeter is surrounded by an unusually exuberant grasses that stand out from the rest in the general sparse desert vegetation.
• These circles have long interested scientists
From the time that scientists have begun to show interest in them (in the early '70s), it was suggested three main explanations — termites, radioactive soil and toxic debris Euphorbia damarana, the poisonous tree, another called milk bush.
Radioactive theory was easily disproved after the fan Ruoyen took soil samples and test them for radioactivity. To test the hypothesis that plant toxins, scientists have found in the desert a few of these trees, both living and dead, took soil samples from under them. Then they tried to grow in this land of different plants in the laboratory — they found out that the grass Lolium multiflorum in such soil feels very good.
There was only one theory — that the termites has consumed all the seeds within the magic circle, so that there was simply nothing to grow. But the most careful search failed to reveal any signs of termites or their nests.
So where did these circles? Researchers have shown that herbs hireyut on soil samples taken from the very magic circles, but grow even better than expected in the soil samples taken around the perimeter of the community. This means that these two types of soil are somewhat different. But why — is still unknown.