The mystery of ‘fairy realms’ in Namibia solved

The ‘fairy circles’ found in the grasslands of Namibia have puzzled scientists for almost five decades, but now a new study has shed more light on this amazing natural phenomenon.

In the Namib coastal desert, 80 to 140 km from the Atlantic coast, there are millions of circles on the ground, each a few meters wide.

These circles are thought to be created by termites, but new research published in the journal Perspectives in Plant Ecology, Evolution and Systematics suggests that the circles in grasslands may be caused by the grass itself. have adapted themselves to very limited water availability.

The study examined occasional rainfall in several desert regions and analyzed potential damage to grass roots, including grass roots and leaves, by termites to define the boundaries and concluded that ‘ “Fairy circles” were formed by plants due to water stress.

The researchers, including some from the University of Göttingen in Germany, found that grasses ‘organize’ themselves to distribute water in a geometric pattern to survive.

The researchers installed soil moisture sensors in and around the fairy circles from the dry season of 2020 to the end of the rainy season of 2022 to measure the amount of water in the soil at 30-minute intervals.

The scientists also studied how the new grass growth around the circles affected the soil water in and around the circles. They estimated the difference in water leakage into and out of circles in 10 regions of the Namib.

The results showed that about 10 days after the rain, the grass inside the circles had already started to die, while most of the inner part of the circles did not sprout.

About 20 days after the rain, the hardy grass inside the circles was completely dead while the surrounding grass was green.

Later, the scientists examined the grass roots inside the circles and compared them to the green grass outside.

They found that the grass roots inside the circles were significantly longer or longer than the grass roots outside, indicating that the grass extended the roots in search of water.

However, scientists found no evidence of termite feeding on grass roots, and damage to dead grass roots became more noticeable 50 to 60 days after rain.

Study co-author Stephen Gatzen explained that ‘termite activity cannot explain the sudden disappearance of much of the grass within the enclosures because there was nothing for the termites to eat.’

Dr Gaetzen said: ‘But more importantly, we could show that termites were not responsible because the grass died immediately after the rain, with no sign of the termite feeding on the roots.’

The scientists also found that soil water loss inside and outside the circles was very slow after the initial rain when the grass had not yet taken root.

But when the surrounding grass grew well, the water content in the soil decreased rapidly in all areas after the rain, even though there was almost no grass taking up water inside the circles.

According to Dr Gatzen: ‘Due to extreme heat in the Namib, grasses are constantly being drained and dehydrated. So it creates a vacuum in the soil around its roots and water is drawn towards it.’

Scientists say that grasses act as ‘ecosystem engineers’ and directly benefit from the water they receive through green breaks.

Dr Gaetzen says, ‘In fact, we know of relatively few other arid regions around the world that are self-organizing, and in all these cases the plants have no choice but to survive. They would have developed in such a geometrical form.’