A larger part of the Amazon rainforest is at risk of crossing a tipping point where it could become a savanna-type ecosystem than previously thought, according to new research. The research, based on computer models and data analysis, is published in the journal Nature Communications.
Rainforests are very sensitive to changes that affect rainfall for extended periods. If rainfall drops below a certain threshold, areas may shift into a savanna state.
“In around 40 percent of the Amazon, the rainfall is now at a level where the forest could exist in either state — rainforest or savanna, according to our findings,” says lead author Arie Staal, formerly a postdoctoral researcher at the Stockholm Resilience Centre and the Copernicus Institute of Utrecht University.
The conclusions are concerning because parts of the Amazon region are currently receiving less rain than previously and this trend is expected to worsen as the region
Archaeologists have uncovered a warrior burial in Berkshire that could change historians’ understanding of southern Britain in the early Anglo-Saxon era.
The burial, on a hilltop site near with commanding views over the surrounding Thames valley, must be of a high-status warlord from the 6th century AD, archaeologists from the University of Reading believe.
The ‘Marlow Warlord’ was a commanding, six-foot-tall man, buried alongside an array of expensive luxuries and weapons, including a sword in a decorated scabbard, spears, bronze and glass vessels, and other personal accoutrements.
The pagan burial had remained undiscovered and undisturbed for more than 1,400 years until two metal detectorists, Sue and Mick Washington came across the site in 2018.
Sue said: “On two earlier visits I had received a large signal from this area which appeared to be deep iron and most likely not to be of interest. However, the uncertainty preyed on my mind
Strictly speaking, humans cannot digest complex carbohydrates — that’s the job of bacteria in our large intestines. UC Riverside scientists have just discovered a new group of viruses that attack these bacteria.
The viruses, and the way they evade counterattack by their bacterial hosts, are described in a new Cell Reports paper.
Bacterioides can constitute up to 60% of all the bacteria living in a human’s large intestine, and they’re an important way that people get energy. Without them, we’d have a hard time digesting bread, beans, vegetables, or other favorite foods. Given their significance, it is surprising that scientists know so little about viruses that prey on Bacteroides.
“This is largely unexplored territory,” said microbiologist Patrick Degnan, an assistant professor of microbiology and plant pathology, who led the research.
To find a virus that attacks Bacteroides, Degnan and his team analyzed a collection of bacterial genomes, where viruses can
The largest-ever study of tree rings from Norilsk in the Russian Arctic has shown that the direct and indirect effects of industrial pollution in the region and beyond are far worse than previously thought.
An international team of researchers, led by the University of Cambridge, has combined ring width and wood chemistry measurements from living and dead trees with soil characteristics and computer modelling to show that the damage done by decades of nickel and copper mining has not only devastated local environments, but also affected the global carbon cycle.
The extent of damage done to the boreal forest, the largest land biome on Earth, can be seen in the annual growth rings of trees near Norilsk where die off has spread up to 100 kilometres. The results are reported in the journal Ecology Letters.
Norilsk, in northern Siberia, is the world’s northernmost city with more than 100,000 people,
The toughest organisms on Earth, called extremophiles, can survive extreme conditions like extreme dryness (desiccation), extreme cold, space vacuum, acid, or even high-level radiation. So far, the toughest of all seems to be the bacterium Deinococcus radiodurans—able to survive doses of radiation a thousand times greater than those fatal to humans. But to this date, scientists remained puzzled by how radio-resistance could have evolved in several organisms on our planet, naturally protected from solar radiation by its magnetic field. While some scientists suggest that radio-resistance in extremophile organisms could have evolved along with other kinds of resistance, such as resistance to desiccation, a question remained: which genes are specifically involved in radio-resistance?
To address this question, the team of Dr. Cox, at the University of Wisconsin-Madison,
A warming climate and more frequent wildfires do not necessarily mean the western United States will see the forest loss that many scientists expect. Dry forest margins may be more resilient to climate change than previously thought if managed appropriately, according to Penn State researchers.
“The basic narrative is it’s just a matter of time before we lose these dry, low elevation forests,” said Lucas Harris, a postdoctoral scholar who worked on the project as part of his doctoral dissertation. “There’s increasing evidence that once disturbances like drought or wildfire remove the canopy and shrub cover in these dry forests, the trees have trouble coming back. On the other hand, there’s growing evidence that there’s a lot of spatial variability in how resilient these forests are to disturbances and climate change.”
The researchers studied forest regeneration at four sites that had experienced wildfires in the eastern Sierra Nevada Mountains in