Fairy Circles These mysterious circles of bare ground are scattered along a 2000km stretch of desert

Fairy CirclesThese mysterious circles of bare ground are scattered along a 2000km stretch of desert, from Angola down to South Africa. They are typically surrounded by a thick patch of grass on their perimeter and are most frequent in the Namib desert, Namibia, shown in this image.Their origin has remained a mystery until recent research, which analysed many years worth of satellite images. The data indicated regular appearance and disappearance of the circles, with an extrapolated average lifetime of 41 years, indicating that the features were active and therefore likely biological in origin.In 2013, the German ecologist Norbert Juergens then became fascinated by the circles and determined to discover their cause. Sampling 1200 circles over 40 field trips, only sand termites were a constant biological presence at all sites. He proposed that the termites burrow and consume plant roots within the circle, preventing any growth of new plants so that their roots do not remove the moisture that keeps the termites hydrated. His research has been well received, however an older, alternative theory of self-organisation is becoming more prominently recognised as the cause, initially proposed decades ago by the great mathematician, Alan Turing.The most recent mathematical modelling suggests that the death of weak plants and the growth of larger plants in these soils creates this formation naturally, with the bare patches acting as small troughs of water that will last through several dry months. The plants slowly tap in to these wells, sustained by the water supply when rainfall is absent. Similar circles have also recently been studied in Australia, with a similar conclusion of self-organisation for the maximisation of water and nutrient intake.-WAVImage Credit: Norbert Juergens (http://nyti.ms/1XknJHg)References:http://nyti.ms/1XknJHghttp://bit.ly/1qwYV4q -- source link
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