Fairy Circles Found At Namibia's Coast
Fairy
circles are discs of completely bare sandy soil anything from two to
10 metres in diameter. Found exclusively along the western coastal
fringes of the Namib desert in southern Africa, they are easy to spot
because they are barren in the middle yet have unusually lush
perimeters of tall grasses, which stand out from the otherwise sparse
vegetation of the desert. From the time researchers began to take an
interest in how they were formed in the early 1970s, three major
explanations emerged: termites, radioactive soil and toxic debris left
in the soil by Euphorbia damarana, the poisonous milkbush
plant. Also read about this in the publication New
Scientist.
E tornano i cerchi nel grano. La studiosa americana Marjorie Tomkins
ha intervistato quest'estate, in Gran Bretagna, due signore africane,
giunte una dal Sudafrica e una dalla Namibia per osservare i cerchi
inglesi, e che le hanno dichiarato di avere osservato dei crops sul
suolo africano. La prima formazione e' stata notata sulla sabbia del
deserto della Namibia, la seconda in un campo di erba rada in Angola.
Le due signore hanno potuto osservare le curiose formazioni, lunghe
chilometri, sorvolando le zone in aereo. I crops sono stati descritti
come perfettamente circolari.
Collaborazione: Marjorie Tomkins.
"South African botanists say they have failed to explain the mysterious round patches of bare sandy soil found in grassland on Namibia's coastal fringe."
"They looked at possible causes of the 'fairy circles'--radioactive soil, toxic proteins left by poisonous plants, and termites eating the seeds."
"But tests failed to support any of these theories for the 'rings,' which measure 2 to 10 metres (6.6 to 66 feet) in diameter."
"For now, they say, they are left with 'fairies' to explain the phenomenon."
"Lead scientist Gretel van Rooyen is now exploring the theory that, somehow, toxic elements are deposited in the shape of a circle, making it impossible for plant life to get established there, Agence France Presse reported."
"'But even if we find them, how came they there is the next problem--for the moment, we're left with the fairies,' Ms. van Rooyen, a botanist at the University of Pretoria, said."
"Tests of soil samples taken from 'fairy circles' found all to be negative for radioactivity, and desert plants were successfully grown in the lab on soil on which only milk bushes had grown."
"As for termites, the team dug trenches up to 2 metres deep in and around the circles, but found no sign of these insects or their nests."
"'Fairy circles' occur in a broken belt in the pro- Namib region, from southern Angola to the Orange River in South Africa and have become so famous that they are included in various (African) tours." (See the Agence France Presse report for March 31, 2004. Many thanks to Robert Fischer for this news story.)
