Most of the Namib desert is dry, barren and lifeless. The occasional rain shower will bring with it a few days of intense colour as the dormant plants grow rapidly. The most striking plant in the Namib is the Welwitschia, which grows only two leaves that tear and split through the life of the plant.
But along an 1800km strip of land in the Namib are unexplained circles of barren land surrounded by lush grass. These are the “fairy circles” and can be anything from around 2m to 15m in diameter and are completely barren inside the ring of grass. The circles even have a lifespan – they appear, grow and die, living up to 75 years. So far, they have defied any scientific explanation, but that hasn’t stopped the theories coming in.
The myths – gods and dragons
The myth surrounding the fairy circles passed down by the Himba people is that the circles were created by gods or spirits. Some say that they are footprints of the gods, others day that a dragon lives in the sand and that the poisonous breath kills the vegetation.
One theory put forward was that termites caused the circles in order to create a better habitat. First feeding on the roots of plants and killing them, the termites create an area where water can pool below the sand because there is no vegetation to absorb the moisture. This keeps the termites happy, but the excess water helps the ring of grass to grow.
The Damara Granite of the Namibian desert often contains Uranium and Potassium 40. If the sand in the area was formed from the Damara Granite, it could be radioactive! This would cause three distinct radioactive zones which create a vegetation pattern seen in the fairy circles – a lethal zone where nothing grows, an effects zone where some vegetation grows and a no effects zone where there is no radioactive effect. Each circle could, according to this theory, be a mini radioactive area.
Resource competition between different species of vegetation is thought to be a cause of crop circles and in grassy landscapes, barren spots can occur when different types of grasses compete for water and nutrients under-ground. Could the grass actually be eating itself to cause the Fairy Circles?
Allelopath – the theory of the toxic plants
The Melkbos or Damara milk-bush plant is considered the most toxic plant in Namibia. The milky latex from the plant is said to be able to kill animals and humans. The plant is often used to poison watering holes in order to catch game that have drunk the poisened water. The melkbos is a possible contender for the fairy circles, with the theory being that the residue left by a dead melbos plant creates an area in which no other plants can grow.
Gas – the scientists’ dragon
Could gas leakage be causing the circles? Scientist collected soil samples from the fairy circles and found that seeds planted in the samples didn’t last very long. Chemical analysis led scientists to believe that natural gas leaking underground could be creating the formations by killing off plants in circular patches. Maybe there really is something to that dragon theory.