Subscribe free to our newsletters via your
. Earth Science News .

Subscribe free to our newsletters via your

Researchers find microbial heat islands in the desert
by Staff Writers
Tempe AZ (SPX) Jan 21, 2016

The desert outside Chandler, Ariz., shows a darkening of the biocrust (left) over its surface. Image courtesy Ferran Garcia-Pichel, Arizona State University. For a larger version of this image please go here.

Deserts are often thought of as barren places that are left exposed to the extremes of heat and cold and where not much is afoot. But that view is being altered as new research keeps revealing the intricate ecological dynamics of deserts as they change responding to the elements.

New research from Arizona State University now reveals how microbes can significantly warm the desert surface by darkening it, much in the same way that dark clothes will make you feel warmer in sunlight. These desert-darkening organisms make a living basking in the sun and form a mantle that covers the landscape.

Such mantles, called biological soil crusts, or biocrusts, provide important ecosystem services, like fighting erosion and preventing dust storms, or fertilizing the ground with carbon and nitrogen.

The new ASU research shows how the biocrust microorganisms, in an effort to protect themselves from harmful ultraviolet rays in the strong desert sun, produce and lay down so much sunscreen as to noticeably darken the soil, changing the reflectivity of the desert surface as they spread across the land.

The research is outlined in the article "Bacteria increase arid-land soil surface temperature through the production of sunscreens," published in the Jan. 20, 2016 issue of Nature Communications. It was written by Estelle Couradeau, a Marie Curie postdoctoral fellow at Arizona State University, and Ferran Garcia-Pichel, an ASU professor and Dean of Natural Sciences in the College of Liberal Arts and Sciences.

It is part of a long-term institutional collaboration with Lawrence Berkeley National Laboratory, whose fellow scientists Trent Northen, Ulas Karaoz, Hsiaon Chiem Lin, Ulisses Nunes da Rocha and Eoin Brodie, are co-authors of the paper.

"We have found that the presence of sunscreen-bearing crusts can actually raise local surface temperature by as much as 10 degrees C (18 degrees F). Because globally they cover some 20 percent of Earth's continents, biocrusts, their microbes and sunscreens must be important players in global heat budgets," said Couradeau. "We estimate that there must be some 15 million metric tons of this one microbial sunscreen compound, called scytonemin, warming desert soils worldwide," added Couradeau, the lead author of the paper.

Couradeau spent the last three years studying biocrusts in the laboratory of Garcia-Pichel.

"An increase of 18 degrees F is not without consequence, and we can show that the darkening of the crust brings about important modifications in the soil microbiome, the community of microorganisms in the soil, allowing warm-loving types to do better," Garcia-Pichel added.

"This warming effect is likely to speed up soil chemical and biological reactions, and can make a big difference between being frozen or not when it gets cold," he explained. "On the other hand, it may put local organisms at increased risk when it is already quite hot."

Couradeau and Garcia-Pichel said that while biocrusts have been overlooked in the past they are now getting much closer scrutiny from scientists.

"Biocrusts, while cryptic, deserve more consideration from us," concluded Couradeau. "We need to include them in our climate models and speak about them in the classroom."


Related Links
Arizona State University
Darwin Today At

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Previous Report
University of Alberta researcher tracks tyrannosaur's trail
Edmonton, Canada (SPX) Jan 19, 2016
Just outside the tiny town of Glenrock, Wyoming the footprints of a 66 million-year-old monster are cemented in stone. This fossil trackway was brought to light with the help of University of Alberta paleontologist Scott Persons, who first viewed the tracks as a 13-year-old while visiting the Glenrock Paleon Museum. "The Paleon is an unusual place. It's not a big museum, but it doesn't hav ... read more

Charities warn of 'desperate' plight of refugees in snow

Nepal quake rebuilding to take years, new chief says

MH370 search finds new shipwreck, but no plane

Six years on, quake-devastated Haiti mourns its dead

Recycling light

Polymer puts new medical solutions within reach

All-antiferromagnetic memory could get digital data storage in a spin

It's a 3-D printer, but not as we know it

Livermore scientists find global ocean warming has doubled in recent decades

Global warming strikes deep into oceans: study

Living fossils and rare corals revealed

Volunteers send water as S.African temperatures soar

Mounting evidence suggests early agriculture staved off global cooling

Ancient underwater volcanoes may have ended 'Snowball Earth'

Study finds high melt rates on Antarctica's most stable ice shelf

Human-made climate change suppresses the next ice age

Eating less meat might not be the way to go green

A tree or not a tree? India's Goa rows over coconut status

S.Africa to import maize after driest season in 100 years

Bird flu detected in US turkey flock

Kobe marks 21 years since killer quake

More than 1,200 flee as Indonesia volcano spews ash, gas

Study: Mild winter followed ancient eruption of Toba volcano

Evidence of large volcanic activity in the Caribbean uncovered

Several dead as Shebab storm African Union base in Somalia

China's imports from Africa plummet in 2015: officials

Niger holds 13 over failed December coup

Mali extends state of emergency until March 31

Study: 920,000 Pygmies living in forests of Central Africa

Harmful mutations have accumulated during early human migrations out of Africa

Chimp friendships are based on trust

Brain monitoring takes a leap out of the lab

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.