Fairy Rings – Enigmatic Features of Namibia

22.11.2012

Fairy Rings – Enigmatic Features of Namibia

WANJA NJUGUNA

Prof Eugene Moll chatting with Polytechnic of Namibia 

lecturer and co-author of Trees and Shrubs of Namibia and 

Tree Atlas of Namibia Ms. Barbara Curtis during the talk at 

Namibia Botanical Research Institute last Monday. 

 Picture by Wanja Njuuguna

 FOR CLOSE to 30 years now since a study on them began in earnest, the enigmatic fairy circles or rings of Namibia are still just that – enigmatic.

The circles look like nothing out of the ordinary – just some round bare space in the middle of some dry area or grassland, often in the desert or even on a dune or just somewhere in the wild but to date, the reason behind them is still one of nature’s most guarded secrets.

Just as unique to Namibia as Welwitschia mirabilis an endemic to the Namib desert is, the circles are only know to be found in Idaho in the U.S.A.

MYSTERY ... A picture of the ‘unexplained’
circles.

The circles are barren land with no vegetation but with their perimeters more often than not marked by some taller [more robust] grass such as Stipagrostis giessii around them while between them is another other type of grass, Stipagrostis uniplumis commonly found in the Namib desert. These circles are more prolific in Namibia but they are also found in southern Angola and just into the northern part of South Africa.

The secret to their occurrence has brought renowned plant scientist, Prof Eugene Moll back to the country to see if this time around, he can dig up the secret behind why these unique features occur.

During a talk organised by the Botanical Society of Namibia last week Monday, Moll, currently in Namibia undertaking research in the south of Namibia on these 'circles' or 'rings' as he prefers to call them said that he hopes that this time around he will come close to the reason of their occurrence.

Describing them as sometimes concave (especially in the North) bares circles or ellipses generally occur in a monospecific grassland matrix only on sandy, calcrete and pebbly ground. “They can be small (2-4 metres in the south and west) or usually much bigger (up to 10 by 15 meters in the north),” he explained.

While their causes are just as intriguing, Moll said that though to date the causes of the rings are not known, there are however many theories about their origins. “Some of the fancy theories are such as that they are made by fairies, dragons and extra-terrestrials while the more scientific theories include underlying geological faults, plants or animals remains such as euphorbia damarana, fossorial animals, termites and seed-harvesting ants among others. They are also said to be geochemical in origin,” he explained.

But one fascinating aspect of the rings is that they are not found in the Kalahari. “The Kalahari is one of the most exciting places to find many kinds of species but these are not found there,” Moll said.

Researchers C.F Albrecht, J.J. Joubert and P.H de Rycke concur in a research they conducted about 10 years ago. They said that besides the research of K. L Tinley (1974) who described the rings as fossilize termitaria, other more trivial explanations have been given as impact points of broken-up meteorites, rolling spots for zebras, indications of locations of Ovahimba huts, localized radioactivity and even locations of ‘Flying Saucers”. Among the Ovahimba people, some of the oral myths include gods, spirits and natural divinities as causes of the rings.

Many studies by scientists in Namibia and Southern Africa area concur that the rings which grow to between two and 12 meters in diameter, are a continuous development, though close to 30 years later, their reason for existence is still a mystery.

Moll also discussed Tinley’s work saying that published suggestions that would be also reliable include G. K. Theron who in 1979 implicated that they were Euphorbia damarana 'graves' in their formation while in a study done and published by Theron and colleagues A. Eiker and N. Grobbelaar suggested microbial action inhibiting grass growth.

In a paper he wrote in 1994, Moll, just like Eiker, felt termites had something to do with the rings but unlike some of the writers, he feels that the rings are still alive. There are also researchers such as Walter Tschinkel (2011) who postulated that fairy rings 'appear quickly and fade away slowly' over a period of years, besides the fact that they are alive. 

It is believed that because the areas where the rings are found is said to be in some of the most remote and inhospitable areas on the planet, this might be a cause for the non-intensive research on these unique features. It is generally felt, however that there is some biological origin and/or toxic gas component involved in their formation, related perhaps to toxins left by poisonous plants but this too is not proven as yet, something that Prof Gretel van Rooyen, botanist from the University of Pretoria concurs with.

Moll said that the research he and his team are carrying out is bringing forth some interesting findings. “Our recent research using ground penetrating radar, shows a 'curtain' below the rim extending to as deep as 10 meters,” Moll explained. “This is present in all kinds of fairy rings with live grass roots at 1.2 meters and more, suggesting a biologically active lens underlain by a more moist deeper soil layer,” he added. 

In his earlier research, which is also quoted by Albrecht et al., Moll says that termites were the main agents in the ring formation and that the lack of vegetation in the rings was compatible with surface foraging by the termites. In support of this theory, he found termite casts and a few individual termites after digging a trench of 0.75m deep and 0.30m wide through a number of the rings (see picture). The termites were identified as Baucaliotermes hainsei (Fuller) and Psammotermes allocerus (Silverstri). His research showed that there were rings in different stages of colonization by plants, thereby concluding that the rings were dynamic. 

The plant ecologist who is also professor extraordinaire in the Department of Biodiversity & Conservation Biology at the University of the Western Cape, is author of, “What's that Tree? A Starter's Guide to Trees of Southern Africa”, the latest edition to the 'What's that' series that includes birds, snakes, butterflies and reptiles. The book, which is also available as an eBook dispels myths regarding African baobabs, rhino horns (as aphrodisiacs), tannin and phenol content of certain trees and shrubs. 

http://www.namibian.com.na/news/full-story/archive/2012/november/article/fairy-rings-enigmatic-features-of-namibia/