Fairy Circles of Namibia: A Science Mystery
A web-based activity exploring an unsolved scientific mystery

created by Kaye Placing
UniServe Science

Introduction | The Process and Resources | Follow-up |



Introduction

The "fairy circles" of Namibia remain an unexplained mystery of Science.

The "fairy circles" (also known as "fairy rings") are found in the desert regions of southern Africa, in a belt which runs north-south in a line, roughly parallel to the coastline, from Angola in the north, through Namibia into South Africa. They occur on sandy plains where vegetation is scarce except following rain. They vary in size from about 10 metres in diameter in the north of Namibia (Hartmann's Valley) to less than 3 metres in the south.

"These circular, slightly concave depressions are devoid of vegetation and often surrounded by a fringe of tall grass. Although seedlings are sometimes found in these barren patches after good rainfall, they usually do not survive, leaving patches completely bare for most of the time." (van Rooyen, Theron, van Rooyen, Jankowitz and Matthews 2004).
Most of the localities where fairy circles occur lie in areas that experience between 50 and 100 mm of rainfall per year. In general the altitude ranges between 500 and 1000 m. The localities are found roughly between 60 and 120 kilometres from the coast.

Despite 25 years of research, the cause of these "fairy circles" is unknown.

In June 2003, the results of a study by researchers from the University of Pretoria and the Polytechnic of Namibia into the origin of the "fairy circles" of Namibia were published in the Journal of Arid Environments.




Background resources

Find out a little more about what these "fairy circles" look like and where they are located:




Task and resources

Following the publishing of this research paper, the following reports were published on the Web. Your task is to look at these reports and answer the following questions.
  1. Outline the three theories for the formation of the "fairy circles" that were investigated by the research team?
  2. How were the three theories investigated?
  3. What were the findings of the investigation?
  4. What further research is planned by the research team?
  5. What other possible explanations have been put forward to explain the "fairy circles"?




Follow-up

  1. What is meant by the term "allelopathy"?




Bibliography

van Rooyen, M.W., Theron, G.K., van Rooyen, n., Jankowitz, W.J. and Matthews, W.S. (2003) Mysterious circles in the Namib Desert: review of hypotheses on their origin. Journal of Arid Environments, 57, 467-485.


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