Sahara Fragile

Main Menu

  • Home
  • Sahara desert
  • Namib desert
  • Kalahari desert
  • Savanna desert
  • Fragile States

Sahara Fragile

Header Banner

Sahara Fragile

  • Home
  • Sahara desert
  • Namib desert
  • Kalahari desert
  • Savanna desert
  • Fragile States
Kalahari desert
Home›Kalahari desert›Mysterious fairy circles in the Namibian desert finally explained

Mysterious fairy circles in the Namibian desert finally explained

By Christopher J. Jones
January 18, 2017
0
0


[ad_1]

Through Sam wong

How are they formed?

Jean Guyton

The Namib Desert is covered in regular patterns of bare circles whose origin is fiercely debated by researchers – but now it seems that the two main explanations are correct.

One camp claims that the empty areas, known as fairy circles, are created by termites under the ground that clear the vegetation around their nests. By making the soil porous, the argument goes, they establish permanent reservoirs of rainwater 50 centimeters below the surface, which supports them and the surrounding ecosystem.

An alternative idea is that the circles are explained by plants competing for water. Plants help their closest neighbors by creating shade and keeping water on the surface of the soil, but annoy those farther away by growing long roots that pull water out of the soil.

The theory of competition in water may explain regular patterns perfectly, but has not been proven in any test, says Corina Tarnita from Princeton University. Meanwhile, the termite theory is supported by observations of termite nests in the circles, but could not explain why the patterns are so regular.

“Each brought what we thought were compelling arguments,” she says.

Termite nests

So Tarnita and her colleague Rob pringle turned to computer models. They first created one to determine if termites could end up with even spacing between their nests.

Termites feed in a circular area around their nest. When they encounter a smaller termite colony, they destroy it and take over the territory.

But when two colonies of similar size clash, neither can defeat the other and they establish a border.

The model showed that this competition between termite colonies can lead to a regular honeycomb pattern, with each colony surrounded by six neighboring colonies. In addition to Namibian fairy circles, Tarnita and Pringle say this motif can be seen in termite colonies in Arizona, Brazil, Kenya, Mozambique, and Australia.

The couple then wondered what would happen if the competition of plants for water was also at work. “Why does it have to be one or the other?” Tarnita asks.

Their model predicted that there would be two models: a large-scale model of bare circles, created by termites, and a smaller model in vegetation between circles, resulting from competition for water.

Miniature circles

When they went to Namibia to see the fairy circles for themselves, they saw these smaller circles, about eight inches in diameter and eight inches apart. They had not been reported before.

“The fairy circles got so much attention that people didn’t pay attention to the appearance of the vegetation between the circles,” says Tarnita. Their observations match the model’s prediction, suggesting that the two mechanisms act simultaneously.

Norbert Jürgens from the University of Hamburg, Germany, a longtime proponent of termite theory, is happy that the new study supports their involvement. “Now it’s a balanced discussion,” he says.

But not everyone is convinced. Last year, Stephane Getzin at the Helmholtz Center for Environmental Research in Leipzig, Germany, reported fairy-circle patterns in the Australian outback, much like those found in Namibia.

Getzin says there are no termites in parts of Namibia and Australia where circles are found, and in others there is no correlation between circles and termites. “Logically, if there are fairy circles without the presence of termites, the termite theory cannot be considered a strong explanation for the phenomenon,” he says.

Jürgens says in a decade of research he’s never seen fairy circles without at least some indicators of termites, and offers to help anyone who can’t find them. “I’m happy to help,” he says.

It seems that the turf war is not over yet.

Journal reference: Nature, DOI: 10.1038 / nature20801

Read more: What causes mysterious fairy circles to appear in the desert?

More on these topics:

[ad_2]

Related posts:

  1. Operation Kalahari Desert: officers should act only on instructions
  2. A remnant of a brilliant fireball that exploded over Africa has been recovered from the desert
  3. A thriving artists’ colony in the South African desert
  4. Teamwork in the Desert Explains the Global Model of Bird Cooperation
Tagsnamib desert

CATEGORIES

  • Fragile States
  • Kalahari desert
  • Namib desert
  • Sahara desert
  • Savanna desert

RECENT POSTS

  • In South Dakota and Nebraska Deep Red, voters used ballot initiatives to reduce inequality
  • Innovative solution for financial ills
  • “We were abandoned in the desert at 2 a.m.”: migrants expelled from Algeria to Niger
  • ILoveBoobies participates in Desert Dash
  • Land Bank Self-sufficiency is a mirage in the desert | News, Sports, Jobs

ARCHIVES

  • November 2022
  • October 2022
  • September 2022
  • August 2022
  • July 2022
  • June 2022
  • May 2022
  • April 2022
  • March 2022
  • February 2022
  • January 2022
  • December 2021
  • November 2021
  • October 2021
  • September 2021
  • August 2021
  • July 2021
  • June 2021
  • May 2021
  • April 2021
  • March 2021
  • February 2021
  • January 2021
  • December 2020
  • November 2020
  • October 2020
  • September 2020
  • August 2020
  • July 2020
  • June 2020
  • May 2020
  • April 2020
  • March 2020
  • February 2020
  • January 2020
  • December 2019
  • November 2019
  • October 2019
  • September 2019
  • August 2019
  • July 2019
  • June 2019
  • May 2019
  • April 2019
  • February 2019
  • January 2019
  • December 2018
  • October 2018
  • September 2018
  • August 2018
  • July 2018
  • June 2018
  • May 2018
  • April 2018
  • March 2018
  • February 2018
  • January 2018
  • December 2017
  • October 2017
  • September 2017
  • August 2017
  • June 2017
  • May 2017
  • March 2017
  • January 2017
  • November 2016
  • October 2016
  • September 2016
  • August 2016
  • June 2016
  • May 2016
  • April 2016
  • March 2016
  • January 2016
  • November 2015
  • July 2015
  • May 2015
  • April 2015
  • January 2015
  • December 2014
  • October 2014
  • September 2014
  • June 2014
  • May 2014
  • January 2014
  • November 2013
  • October 2013
  • September 2013
  • April 2013
  • March 2013
  • November 2012
  • May 2012
  • October 2011
  • November 2010
  • April 2008
  • July 2006
  • November 2005
  • Privacy Policy
  • Terms and Conditions