In deserts and other arid lands, microbes often form very thin top layers on soil known as biocrusts, which behave a bit like Rip Van Winkle. He removed himself from a stressful environment by sleeping for decades, and awoke to a changed world; similarly, the biocrust’s microbes lie dormant for long periods until precipitation (such as a sudden downpour) awakens them. Understanding more about the interactions between the microbial communities—also called “microbiomes”—in the biocrusts and their adaptations to their harsh environments could provide important clues to help shed light on the roles of soil microbes in the global carbon cycle. (more…)
Tag Archives: carbon cycle
A new NASA-led study seven years in the making has confirmed that natural forests in the Amazon remove more carbon dioxide from the atmosphere than they emit, therefore reducing global warming. This finding resolves a long-standing debate about a key component of the overall carbon balance of the Amazon basin.
The Amazon’s carbon balance is a matter of life and death: living trees take carbon dioxide out of the air as they grow, and dead trees put the greenhouse gas back into the air as they decompose. The new study, published in Nature Communications on March 18, is the first to measure tree deaths caused by natural processes throughout the Amazon forest, even in remote areas where no data have been collected at ground level. (more…)
Geologist Adam Wallace reports in ‘Science’ that calcium carbonate has a dense liquid phase
Computer simulations could help scientists make sense of a recently observed and puzzling wrinkle in one of nature’s most important chemical processes. It turns out that calcium carbonate — the ubiquitous compound that is a major component of seashells, limestone, concrete, antacids and other naturally and industrially produced substances — may momentarily exist in liquid form as it crystallizes from solution.
“Our simulations suggest the existence of a dense liquid form of calcium carbonate,” said co-corresponding author Adam Wallace, an assistant professor of geological sciences in UD’s College of Earth, Ocean, and Environment who conducted the research while a postdoctoral researcher at the Lawrence Berkeley National Laboratory. “This is important because it is an as-yet unappreciated component of the carbon cycle.” (more…)
Study reveals micronutrient riches rising from the Southern Mid-Atlantic Ridge
Scientists have discovered a vast plume of iron and other micronutrients more than 1,000 km long billowing from hydrothermal vents in the South Atlantic Ocean. The finding, soon to be published in the journal Nature Geoscience, calls past estimates of iron abundances into question, and may challenge researchers’ assumptions about iron sources in the world’s seas.
“This study and other studies like it are going to force the scientific community to reevaluate how much iron is really being contributed by hydrothermal vents and to increase those estimates, and that has implications for not only iron geochemistry but a number of other disciplines as well,” says Mak Saito, a WHOI associate scientist and lead author of the study. (more…)
Scientists find surprising new answers in wetlands such as the Everglades
Scientists have uncovered one of nature’s long-kept secrets–the true fate of charcoal in the world’s soils.
The ability to determine the fate of charcoal is critical to knowledge of the global carbon budget, which in turn can help understand and mitigate climate change.
However, until now, researchers only had scientific guesses about what happens to charcoal once it’s incorporated into soil. They believed it stayed there.
Surprisingly, most of these researchers were wrong. (more…)
Researchers have discovered four previously unknown viruses that infect the Earth’s most abundant organism, the marine bacterium SAR11. Because of their huge numbers, these tiny players have critical roles in the global cycle of carbon and other nutrients.
The greatest battle in Earth’s history has been going on for hundreds of millions of years, isn’t over yet, and until now no one knew it existed, scientists reported today in the journal Nature.
In one corner is the Earth’s most abundant organism: SAR11, an ocean-living bacterium that survives where most other cells would die and plays a major role in the planet’s carbon cycle. It had been theorized that SAR11 was so small and widespread that it must be invulnerable to attack. (more…)
Berkeley Lab scientists devise new tools for detecting previously unknown tree mortality.
The Earth’s forests perform a well-known service to the planet, absorbing a great deal of the carbon dioxide pollution emitted into the atmosphere from human activities. But when trees are killed by natural disturbances, such as fire, drought or wind, their decay also releases carbon back into the atmosphere, making it critical to quantify tree mortality in order to understand the role of forests in the global climate system. Tropical old-growth forests may play a large role in this absorption service, yet tree mortality patterns for these forests are not well understood.
Now scientist Jeffrey Chambers and colleagues at the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) have devised an analytical method that combines satellite images, simulation modeling and painstaking fieldwork to help researchers detect forest mortality patterns and trends. This new tool will enhance understanding of the role of forests in carbon sequestration and the impact of climate change on such disturbances. (more…)
PASADENA, Calif. – An area of the Amazon rainforest twice the size of California continues to suffer from the effects of a megadrought that began in 2005, finds a new NASA-led study. These results, together with observed recurrences of droughts every few years and associated damage to the forests in southern and western Amazonia in the past decade, suggest these rainforests may be showing the first signs of potential large-scale degradation due to climate change.
An international research team led by Sassan Saatchi of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., analyzed more than a decade of satellite microwave radar data collected between 2000 and 2009 over Amazonia. The observations included measurements of rainfall from NASA’s Tropical Rainfall Measuring Mission and measurements of the moisture content and structure of the forest canopy (top layer) from the Seawinds scatterometer on NASA’s QuikScat spacecraft. (more…)