Dormant desert life hints at possibilities on Mars

Updated 27 February 2018
0

Dormant desert life hints at possibilities on Mars

MIAMI: It may rain once a decade or less in South America’s Atacama Desert, but tiny bacteria and microorganisms survive there, hinting at the possibility of similar life on Mars, researchers said Monday.
The desert, which spans parts of Chile and Peru, is the driest non-polar desert on Earth and may contain the environment most like that of the Red Planet, said the report in the Proceedings of the National Academy of Sciences.
Lead researcher Dirk Schulze-Makuch, a professor and planetary scientist at the Technical University of Berlin, and colleagues took a trip to the desert in 2015 to learn more about what kind of life might exist there. Then, unexpectedly, it rained.
Scientists detected an explosion of biological activity in the soil, and quickly began using sterile spoons to scoop up samples.
Genomic analyzes helped identify the several apparently indigenous species of microbial life — mostly bacteria — that had somehow adapted to live in the harsh environment by lying dormant for years, then re-animating and reproducing once it rained.
“In the past, researchers have found dying organisms near the surface and remnants of DNA, but this is really the first time that anyone has been able to identify a persistent form of life living in the soil of the Atacama Desert,” Schulze-Makuch said.
“We believe these microbial communities can lay dormant for hundreds or even thousands of years in conditions very similar to what you would find on a planet like Mars and then come back to life when it rains.”
Scientists returned to the Atacama in 2016 and 2017 for follow-up visits and discovered that the same microbial communities in the soil were gradually reverting to their dormant state.
But they did not completely die off. Single-celled organisms, found mainly in the deeper layers of the desert, “have formed active communities for millions of years and have evolved to cope with the harsh conditions,” said the PNAS report.
Since Mars had oceans and lakes billions of years ago, researchers say early life forms may have thrived there, too.
The world’s space agencies are sending robotic vehicles to Mars in a bid to uncover signs of life, but any attempt to return samples to Earth will be costly and complicated.
Schulze-Makuch said the research may help scientists home in on ways to study Martian microbes, which might have evolved to the planet’s colder, drier climate over time, much like the Atacama microbes.
“We know there is water frozen in the Martian soil and recent research strongly suggests nightly snowfalls and other increased moisture events near the surface,” he said.
“If life ever evolved on Mars, our research suggests it could have found a subsurface niche beneath today’s severely hyper-arid surface.”


Loss of Earth’s intact forests speeds up: scientists

The last forest frontiers also play a critical role in maintaining biodiversity, weather stability, clean air, and water quality. (Shutterstock)
Updated 20 June 2018
0

Loss of Earth’s intact forests speeds up: scientists

  • Nearly ten percent of undisturbed forests have been fragmented, degraded or simply chopped down since 2000, according to the analysis of satellite imagery
  • Some 500 million people worldwide depend directly on forests for their livelihood

PARIS: Earth’s intact forests shrank annually by nearly 90,000 square kilometers — an area the size of Austria — from 2014 to 2016, 20 percent faster than during the previous 13 years, according to findings presented at a conference in Oxford this week.
Despite UN-led efforts to halt deforestation, nearly ten percent of undisturbed forests have been fragmented, degraded or simply chopped down since 2000, according to the analysis of satellite imagery.
Average daily loss over the first 17 years of this century was more than 200 sq km (75 sq miles).
“Degradation of intact forest represents a global tragedy, as we are systematically destroying a crucial foundation of climate stability,” said Frances Seymour, a senior distinguished fellow at the World Resources Institute, and a contributor to the research.
“Forests are the only safe, natural, proven and affordable infrastructure we have for capturing and storing carbon.”
The last forest frontiers also play a critical role in maintaining biodiversity, weather stability, clean air, and water quality.
Some 500 million people worldwide depend directly on forests for their livelihood.
So-called “intact forest landscapes” — which can include wetlands and natural grass pastures — are defined as areas of at least 500 sq km (200 sq miles) with no visible evidence in satellite images of large-scale human use.
Concretely, that means no roads, industrial agriculture, mines, railways, canals or transmission lines.
As of January 2017, there were about 11.6 million sq km (4.5 million sq miles) of forests worldwide that still fit these criteria.
“Many countries may lose all their forest wildlands in the next 15 to 20 years,” Peter Potapov, an associate professor at the University of Maryland and lead scientist for the research, told AFP.
On current trends, intact forests will disappear by 2030 in Paraguay, Laos and Equatorial Guinea, and by 2040 in the Central African Republic, Nicaragua, Myanmar, Cambodia and Angola.
“There could come a point in the future where no areas in the world qualify as ‘intact’ anymore,” said Tom Evans, director for forest conservation and climate mitigation at the Wildlife Conservation Society.
“It is certainly worrying.”
In tropical countries, the main causes of virgin forest loss are conversion to agriculture and logging. In Canada and the United States, fire is the main culprit, while in Russia and Australia, the destruction has been driven by fires, mining and energy extraction.
Compared to annual declines during the period 2000-2013, Russia lost, on average, 90 percent more each year from 2014 to 2016.
For Indonesia, the increase was 62 percent, and for Brazil it was 16 percent.
The new results are based on a worldwide analysis of satellite imagery, built on a study first done in 2008 and repeated in 2013.
“The high resolution data, like the one collected by the Landsat program, allows us to detect human-caused alteration and fragmentation of forest wildlands,” said Potapov.
Presented at the Intact Forests in the 21st Century conference at Oxford University, the finding will be submitted for peer-reviewed publication, said Potapov, who delivered a keynote to the three-day gathering.
Addressing colleagues from around the world, Potapov also challenged the effectiveness of a global voluntary certification system.
Set up in 1994 and backed by green groups such as the World Wildlife Fund, the self-stated mission of the Forest Stewardship Council (FSC) is to “promote environmentally appropriate, socially beneficial and economically viable management of the world’s forests.”
Many forest-products carry the FSC label, designed to reassure eco-conscious consumers.
But approximately half of all intact forest landscapes inside FSC-certified concessions were lost from 2000 to 2016 in Gabon and the Republic of Congo, the new data showed.
In Cameroon, about 90 percent of FSC-monitored forest wildlands disappeared.
“FSC is an effective mechanism to fragment and degrade remaining intact forest landscapes, not a tool for their protection,” Potapov said.
National and regional parks have helped to slow the rate of decline.
The chances of forest loss was found to be three times higher outside protected areas than inside them, the researchers reported.