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."
Skip Derra | EurekAlert!
Predicting eruptions using satellites and math
28.06.2017 | Frontiers
NASA sees quick development of Hurricane Dora
27.06.2017 | NASA/Goddard Space Flight Center
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
28.06.2017 | Physics and Astronomy
28.06.2017 | Physics and Astronomy
28.06.2017 | Health and Medicine