Astronomers discover clues that unveil the mystery of fast radio bursts

UNLV astrophysicist Bing Zhang contributes to understanding the physical mechanisms of fast radio bursts in three papers published in Nature

UNIVERSITY OF NEVADA, LAS VEGAS

Research News

 

IMAGE: THE FIVE-HUNDRED-METER APERTURE SPHERICAL RADIO TELESCOPE (FAST) IN GUIZHOU, CHINA. view more 

CREDIT: (PHOTO CREDIT: BOJUN WANG, JINCHEN JIANG & QISHENG CUI)

Fast radio bursts, or FRBs - powerful, millisecond-duration radio waves coming from deep space outside the Milky Way Galaxy - have been among the most mysterious astronomical phenomena ever observed. Since FRBs were first discovered in 2007, astronomers from around the world have used radio telescopes to trace the bursts and look for clues on where they come from and how they're produced. 

UNLV astrophysicist Bing Zhang and international collaborators recently observed some of these mysterious sources, which led to a series of breakthrough discoveries reported in the journal Nature that may finally shed light into the physical mechanism of FRBs.

The first paper, for which Zhang is a corresponding author and leading theorist, was published in the Oct. 28 issue of Nature. 

"There are two main questions regarding the origin of FRBs," said Zhang, whose team made the observation using the Five-hundred-meter Aperture Spherical Telescope (FAST) in Guizhou, China. "The first is what are the engines of FRBs and the second is what is the mechanism to produce FRBs. We found the answer to the second question in this paper."

Two competing theories have been proposed to interpret the mechanism of FRBs. One theory is that they're similar to gamma-ray bursts (GRBs), the most powerful explosions in the universe. The other theory likens them more to radio pulsars, which are spinning neutron stars that emit bright, coherent radio pulses. The GRB-like models predict a non-varying polarization angle within each burst whereas the pulsar-like models predict variations of the polarization angle.

The team used FAST to observe one repeating FRB source and discovered 11 bursts from it. Surprisingly, seven of the 11 bright bursts showed diverse polarization angle swings during each burst. The polarization angles not only varied in each burst, the variation patterns were also diverse among bursts. 

"Our observations essentially rules out the GRB-like models and offers support to the pulsar-like models," said K.-J. Lee from the Kavli Institute for Astronomy and Astrophysics, Peking University, and corresponding author of the paper.

Four other papers on FRBs were published in Nature on Nov. 4. These include multiple research articles published by the FAST team led by Zhang and collaborators from the National Astronomical Observatories of China and Peking University. Researchers affiliated with the Canadian Hydrogen Intensity Mapping Experiment (CHIME) and the Survey for Transient Astronomical Radio Emission 2 (STARE2) group also partnered on the publications.

"Much like the first paper advanced our understanding of the mechanism behind FRBs, these papers solved the challenge of their mysterious origin," explained Zhang. 

Magnetars are incredibly dense, city-sized neutron stars that possess the most powerful magnetic fields in the universe. Magnetars occasionally make short X-ray or soft gamma-ray bursts through dissipation of magnetic fields, so they have been long speculated as plausible sources to power FRBs during high-energy bursts. 

The first conclusive evidence of this came on April 28, 2020, when an extremely bright radio burst was detected from a magnetar sitting right in our backyard - at a distance of about 30,000 light years from Earth in the Milky Way Galaxy. As expected, the FRB was associated with a bright X-ray burst. 

"We now know that the most magnetized objects in the universe, the so-called magnetars, can produce at least some or possibly all FRBs in the universe," said Zhang. 

The event was detected by CHIME and STARE2, two telescope arrays with many small radio telescopes that are suitable for detecting bright events from a large area of the sky. 

Zhang's team has been using FAST to observe the magnetar source for some time. Unfortunately, when the FRB occurred, FAST was not looking at the source. Nonetheless, FAST made some intriguing "non-detection" discoveries and reported them in one of the Nov. 4 Nature articles. During the FAST observational campaign, there were another 29 X-ray bursts emitted from the magnetar. However, none of these bursts were accompanied by a radio burst. 

"Our non-detections and the detections by the CHIME and STARE2 teams delineate a complete picture of FRB-magnetar associations," Zhang said. 

To put it all into perspective, Zhang also worked with Nature to publish a single-author review of the various discoveries and their implications for the field of astronomy. 

"Thanks to recent observational breakthroughs, the FRB theories can finally be reviewed critically," said Zhang. "The mechanisms of producing FRBs are greatly narrowed down. Yet, many open questions remain. This will be an exciting field in the years to come."

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Read More

"No pulsed radio emission during a bursting phase of a Galactic magnetar," published in the Nov. 4 issue of Nature.

"The physical mechanisms of fast radio bursts," published in the Nov. 4 issue of Nature. 

"Diverse polarization angle swings from a repeating fast radio burst source," published in the Oct. 28 issue of Nature. 

Cockroach mating habits and developmental features help uncover insect evolution

Researchers from the University of Tsukuba find that a "lost" family of cockroaches may be the missing link in the evolution of insects from prehistoric times to the present day

UNIVERSITY OF TSUKUBA

Research News

 

IMAGE: FLUORESCENCE MICROSCOPY OF EMBRYO OF NOCTICOLA SP. (PHOTO BY FUJITA MARI) view more 

CREDIT: UNIVERSITY OF TSUKUBA

Tsukuba, Japan - Often associated with dirty living conditions and the spread of disease, cockroaches understandably have a bad reputation. But of the 4,600 cockroach species alive today, only a few are considered pests, with most choosing to live in leaf litter, rotten logs, or caves, well away from human habitation.

Despite the discovery of fossils dating to the Carboniferous period ~320 million years ago, the evolution of modern cockroaches from these prehistoric ancestors remains a little hazy. To better understand the relationships among modern cockroaches and potentially shed light on their evolutionary history, researchers led by the University of Tsukuba turned to an often-overlooked group of predominantly cave-dwelling cockroaches called the Nocticolidae.

"Previous work indicated that Nocticolidae are a sister group to Corydiidae (sand-dwelling cockroaches), and that these two families, together with Lamproblattidae, are the most basal subgroups of the order Blattodea, which comprises cockroaches and termites," explains senior author of the study Professor Ryuichiro Machida. "Interestingly, similarities in wing design suggest that Nocticolidae species may also be the closest relatives of the extinct insect order Miomoptera, which is often thought to be the common ancestor of many present-day insects."

Somewhat unusually, mating habits and embryonic development can be used to classify and distinguish the various cockroach families. The researchers therefore examined the mating behavior, ootheca (egg sac) handling, and embryonic development of Nocticola sp. cockroaches, which belong to the family Nocticolidae.

Publishing their findings in a recent issue of Arthropod Systematics & Phylogeny, the researchers observed that short-winged male Nocticola sp. cockroaches rapidly flapped their wings near females before entering into end-to-end copulation. After copulation, females produced an ootheca, which they carried for several days before depositing on the ground. Although such a unique wing-flapping behavior has not previously been observed in cockroaches, the other observed behaviors are consistent with the mating and ootheca handling of Corydiidae species, suggesting a close evolutionary relationship.

Notably though, symbiotic bacteria, which are common to other cockroach families, were not observed in Nocticola sp. However, the egg shape and embryonic development, with the embryo's orientation remaining unchanged, in Nocticola sp. were again consistent with Corydiidae.

"Given the consistencies in mating behavior, egg structure, ootheca handing, and embryonic development between Nocticola sp. and Corydiidae, we predict that there is a close association between Nocticolidae and Corydiidae, supporting a shared common ancestor," says Professor Machida. "Furthering our understanding of the phylogenetic position of Nocticolidae within Blattodea is essential for inferring the higher phylogeny and evolution of insects."

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The article, "Reproductive biology and embryonic development of Nocticola sp. (Blattodea: Nocticolidae)," was published in Arthropod Systematics & Phylogeny at DOI: 10.26049/ASP78-3-2020-03.

 

Game 'pre-bunks' political misinformation by letting players undermine democracy

UNIVERSITY OF CAMBRIDGE

Research News

 

IMAGE: THE TITLE SCREEN OF ONLINE BROWSER GAME HARMONY SQUARE. view more 

CREDIT: GUSMANSON

A short online game in which players are recruited as a "Chief Disinformation Officer", using tactics such as trolling to sabotage elections in a peaceful town, has been shown to reduce susceptibility to political misinformation in its users.

The free-to-play Harmony Square is released to the public today, along with a study on its effectiveness published in the Harvard Misinformation Review.

It has been created by University of Cambridge psychologists with support from the US Department of State's Global Engagement Center and Department of Homeland Security Cybersecurity and Infrastructure Security Agency (CISA).

The gameplay is based on "inoculation theory": that exposing people to a weak "dose" of common techniques used to spread fake news allows them to better identify and disregard misinformation when they encounter it in future.

In this case, by understanding how to incite political division in the game using everything from bots and conspiracies to fake experts, players get a form of "psychological vaccine" against the product of these techniques in the real world.

"Trying to debunk misinformation after it has spread is like shutting the barn door after the horse has bolted. By pre-bunking, we aim to stop the spread of fake news in the first place," said Dr Sander van der Linden, Director of the Cambridge Social Decision-Making lab and senior author of the new study.

Twitter has started using a "pre-bunk" approach: highlighting types of fake news likely to be encountered in feeds during the US election. However, researchers argue that familiarising people with techniques behind misinformation builds a "general inoculation", reducing the need to rebut each individual conspiracy.

In the 10-minute game Harmony Square, a small town neighbourhood "obsessed with democracy" comes under fire as players bait the square's "living statute", spread falsehoods about its candidate for "bear controller", and set up a disreputable online news site to attack the local TV anchor.

"The game itself is quick, easy and tongue-in-cheek, but the experiential learning that underpins it means that people are more likely to spot misinformation, and less likely to share it, next time they log on to Facebook or YouTube," said Dr Jon Roozenbeek, a Cambridge psychologist and lead author of the study.

Over the course of four short levels, users learn about five manipulation techniques: trolling to provoke outrage; exploiting emotional language to create anger and fear; artificially amplifying reach through bots and fake followers; creating and spreading conspiracy theories; polarizing audiences.

In a randomized controlled trial, researchers took 681 people and asked them to rate the reliability of a series of news and social media posts: some real, some misinformation, and even some faked misinformation created for the study, in case participants had already come across real-world examples.

They gave roughly half the sample Harmony Square to play, while the other half played Tetris, and then asked them to rate another series of news posts.

The perceived reliability of misinformation dropped an average of 16% in those who completed Harmony Square compared to their assessment prior to playing. The game also reduced willingness to share fake news with others by 11%. Importantly, the players' own politics - whether they leaned left or right - made no difference.

Having the "control group" who played Tetris allowed the scientists to determine an "effect size" of 0.54 for the study, said Van der Linden.

"The effect size suggests that if the population was split equally like the study sample, 63% of the half that played the game would go on to find misinformation significantly less reliable, compared to just 37% of the half left to navigate online information without the inoculation of Harmony Square," he said.

The project follows other playful attempts by CISA to illustrate how "foreign influencers" use disinformation to target "hot button" issues. A previous demonstration took the example of whether pineapple belongs on pizza.

However, Harmony Square is based on the findings of a number of studies from the Cambridge team showing how similar gamified approaches to digital literacy significantly reduce susceptibility to fake news and online conspiracies.

The team behind the game, which includes the Dutch media agency DROG and designers Gusmanson, have recently worked with the UK Cabinet Office on Go Viral!, an intervention that specifically tackles conspiracies around COVID-19.

Harmony Square is geared towards the politically charged misinformation that has plagued many democracies over the last decade. "The aftermath of this week's election day is likely to see an explosion of dangerous online falsehoods as tensions reach fever pitch," said Van der Linden.

"Fake news and online conspiracies will continue to chip away at the democratic process until we take seriously the need to improve digital media literacy across populations. The effectiveness of interventions such as Harmony Square are a promising start," he said.

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Scientists and students publish blueprints for a cheaper single-molecule microscope

UNIVERSITY OF SHEFFIELD

Research News

 

Scientists and students publish blueprints for a cheaper single-molecule microscope to make the specialist technique more widely available

• A team of scientists and students from the University of Sheffield has published the blueprints for a specialist single-molecule microscope they built for a tenth of the cost of commercially available equipment
• Their paper in Nature Communications provides labs with the build instructions and software needed to run the microscope
• The single-molecule method this microscope is capable of is currently only available in a few specialist labs throughout the world

A team of scientists and students from the University of Sheffield has designed and built a specialist microscope, and shared the build instructions to help make this equipment available to many labs across the world.

The microscope, called the smfBox, is capable of single-molecule measurements allowing scientists to look at one molecule at a time rather than generating an average result from bulk samples and works just as well as commercially available instruments.

This single-molecule method is currently only available at a few specialist labs throughout the world due to the cost of commercially available microscopes.

Today (6 November 2020), the team has published a paper in the journal Nature Communications which provides all the build instructions and software needed to run the microscope, to help make this single-molecule method accessible to labs across the world.

The interdisciplinary team spanning the University of Sheffield's Departments of Chemistry and Physics, and the Central Laser Facility at the Rutherford Appleton Laboratory, spent a relatively modest £40,000 to build a piece of kit that would normally cost around £400,000 to buy.

The microscope was built with simplicity in mind so that researchers interested in biological problems can use it with little training, and the lasers have been shielded in such a way that it can be used in normal lighting conditions, and is no more dangerous than a CD player.

Dr Tim Craggs, the lead academic on the project from the University of Sheffield, said: "We wanted to democratise single-use molecule measurements to make this method available for many labs, not just a few labs throughout the world. This work takes what was a very expensive, specialist piece of kit, and gives every lab the blueprint and software to build it for themselves, at a fraction of the cost.

"Many medical diagnostics are moving towards increased sensitivity, and there is nothing more sensitive than detecting single molecules. In fact, many new COVID tests currently under development work at this level. This instrument is a good starting point for further development towards new medical diagnostics."

The original smfBox was built by a team of academics and undergraduate students at the University of Sheffield.

Ben Ambrose, the PhD lead on the project, said: "This project was an excellent opportunity to work with researchers at all levels, from undergraduates to scientists in national facilities. Between biophysicists and engineers, we have created a new and accessible platform to do some cutting edge science without breaking the bank. We are already starting to do some great work with this microscope ourselves, but I am excited to see what it will do in the hands of other labs who have already begun to build their own."

The Craggs Lab at the University of Sheffield has already used the smfBox in its research to investigate fundamental biological processes, such as DNA damage detection, where improved understanding in this field could lead to better therapies for diseases including cancer.

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 Here's how to improve packaged foods nutrition

News from the Journal of Marketing

AMERICAN MARKETING ASSOCIATION

Research News

 

Researchers from Illinois State University, North Carolina State University, University of South Carolina, and University of Maryland published a new paper in the Journal of Marketing that examines the impact of moving nutrition labels, typically placed on the back of product packages, to the front.

The study, forthcoming in the Journal of Marketing, is titled "Competitive Effects of Front-of-Package Nutrition Labeling Adoption on Nutritional Quality: Evidence from Facts Up Front Style Labels" and is authored by Joon Ho Lim, Rishika Rishika, Ramkumar Janakiraman, and P.K. Kannan.

Can changing food packaging improve product nutrition quality? While this change may be simple, there's a lot at stake.

Diet-related chronic diseases impose a growing burden on the United States economy by increasing costs of health care and widening diet-related health disparities. Since the 1970s, the American diet has shifted considerably towards foods higher in calories and lower in nutritional quality. According to the Centers for Disease Control and Prevention estimates, more than one-third of American adults are obese. Childhood and adolescent obesity rates have also skyrocketed in the last 30 years with one in five school-aged children considered obese. To combat this disconcerting trend, public policy makers, food manufacturers, and grocery retailers have made efforts over time to design nutrition labels that can educate consumers about the nutritional value of the foods they purchase and help consumers make healthier choices. The World Health Organization (WHO) also considers nutrition labeling to be a key policy option for promoting healthier diets.

The packaged food industry has voluntarily taken steps to inform consumers about the nutritional value of food products so that consumers can make better choices. One such initiative undertaken by is the Front-of-Package (FOP) nutrition label. FOP nutrition labels are voluntarily adopted by food manufacturers and provide nutrient information on the front of food packaging in a clear, simple, and easy-to-read format. The FOP labels present the key information listed on the Nutrition Facts Panel (NFP; displayed on the back or side of food packages) more concisely and often include calorie content and the amounts of key nutrients to limit (e.g., saturated fat, sugar, and sodium per serving). In an innovative study, our research team assessed the effect of the introduction of a FOP nutrition label in a product category on the nutritional quality of food products in the category.

The study reports four sets of findings. First, the adoption of FOP nutrition labeling in a product category results in a significant improvement in the nutritional quality of food products in that category. Second, the effect of FOP is stronger for premium (high-priced) brands and brands with a narrower product line breadth. Third, the FOP adoption effect is stronger for unhealthy categories and categories with a higher competitive intensity. Fourth, manufacturers increase the nutritional quality of products by reducing the calorie content and limiting nutrients such as sugar, sodium, and saturated fat.

Lim explains that "This implies that policy makers, in partnership with food manufacturers and retailers, should encourage adoption of voluntary, standardized, and transparent labeling programs and consider options for broadening the information presented in FOP labels. We believe that policy makers should also invest in educational campaigns that inform consumers about the value of FOP labels and that would further incentivize food manufacturers to offer nutritionally better products."

For food manufacturers, the results suggest that they must devote significant resources to product innovation to stay competitive. Specifically, manufacturers in unhealthy and more competitive categories can be more strategic and invest in innovation so they are ready to provide better products following FOP adoption. Rishika adds that "Food retailers should partner with manufacturers and give them incentives to adopt FOP because this can lead to better-quality products for their consumers and help build a positive brand image. Retailers can also promote products with FOP labels, especially in more competitive and unhealthy product categories, which can spur manufacturers toward more innovation and lead to an increase in the nutritional quality of foods over time." The researchers encourage retailers to invest in measures that help monitor and track sales of products with FOP labels and provide this feedback to their manufacturers regularly to speed up the competitive effect of FOP labels. For consumers, the study finds that the brands that adopted FOP labeling offer nutritionally superior products than those that did not adopt the labeling. This result is particularly helpful for time-starved consumers looking to purchase relatively healthier products.

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Full article and author contact information available at: https://doi.org/10.1177%2F0022242920942563

About the Journal of Marketing

The Journal of Marketing develops and disseminates knowledge about real-world marketing questions useful to scholars, educators, managers, policy makers, consumers, and other societal stakeholders around the world. Published by the American Marketing Association since its founding in 1936, JM has played a significant role in shaping the content and boundaries of the marketing discipline. Christine Moorman (T. Austin Finch, Sr. Professor of Business Administration at the Fuqua School of Business, Duke University) serves as the current Editor in Chief.

https://www.ama.org/jm

About the American Marketing Association (AMA)

As the largest chapter-based marketing association in the world, the AMA is trusted by marketing and sales professionals to help them discover what's coming next in the industry. The AMA has a community of local chapters in more than 70 cities and 350 college campuses throughout North America. The AMA is home to award-winning content, PCM® professional certification, premiere academic journals, and industry-leading training events and conferences.

https://www.ama.org

Keeping our cool

To limit global warming, the global food system must be reimagined

UNIVERSITY OF CALIFORNIA - SANTA BARBARA

Research News

 

Fossil fuel burning accounts for the majority of global greenhouse gas emissions, and to the world's credit, several countries are working to reduce their use and the heat-trapping emissions that ensue. The goal is to keep global temperatures under a 1.5° to 2°C increase above preindustrial levels -- the upper limits of the Paris Climate Agreement.

If we stopped burning all fossil fuels this minute, would that be enough to keep a lid on global warming?

Acording to UC Santa Barbara ecology professor David Tilman, petroleum energy sources are only part of the picture. In a paper published in the journal Science, Tilman and colleagues predict that even in the absence of fossil fuels, cumulative greenhouse gas emissions could still cause global temperatures to exceed climate change targets in just a few decades.

The source? Our food system.

"Global food demand and the greenhouse gases associated with it are on a trajectory to push the world past the one-and-a-half degree goal, and make it hard to stay under the two degree limit," said Tilman, who holds a dual appointment at UCSB's Bren School of Environmental Science & Management and at the University of Minnesota. The world's growing population as well as its diet are driving food production practices that generate and release massive and increasing amounts of carbon dioxide, methane and other greenhouse gases into the atmosphere. According to the paper, left unchecked, agricultural emissions alone could exceed the 1.5°C limit by about 2050.

These findings are especially concerning given that we haven't stopped using fossil fuels, Tilman said. And with a 1°C average increase in global temperature since 1880, we've got only a slim margin before global warming results in widespread sea level rise, ocean acidification, biodiversity loss and other effects that will change life as we know it.

"All it would take for us to exceed the two degree warming limit is for food emissions to remain on their path and one additional year of current fossil fuel emissions," Tilman said. "And I guarantee you, we're not going to stop fossil fuel emissions in a year."

Reducing the emissions from food production, "will likely be essential" to keeping the planet livable in its current state, according to the scientists.

Seeds of Solutions

"It's well known that agriculture releases about 30% of all greenhouse gases," Tilman said. Major sources include deforestation and land clearing, fertilizer overuse and gassy livestock, all of which are increasing as the global population increases. In "high-yield" countries such as the U.S., which have the benefit of large scale modern agriculture, intensive animal farming and heavy-handed fertilizer use are major contributors of greenhouse gases. Meanwhile, in "low yield" countries such as those in sub-Saharan Africa, population growth and increasing affluence are driving demand for more food, and toward more "urban" diets that are richer in meat and meat products, Tilman explained.

"Their demand for food is going up, but the farmers don't have the resources to have high yields, so they just clear more and more land," he said.

And yet, it isn't as though we can just stop producing food, which is perhaps the main reason why agricultural emissions have received less attention than fossil fuels as a target for reduction, according to the researchers.

"You can't look at agriculture as if we can somehow get rid of it," said Tilman, whose research focuses on the environmental impacts of agriculture, as well as the links between diet, environment and health. "We need it; it's essential for society."

But, according to the paper's authors, global warming does not have to be an unavoidable impact of feeding the the world. Through early and widespread adoption of several feasible food system strategies, it is possible to limit emissions from agriculture in a way that keeps us from exceeding the 2°C limit by the end of the century while feeding a growing population.

The most effective, according to the paper, is a switch toward more plant-rich diets, which aren't just healthier overall, but also reduce the demand for beef and other ruminant meats. That, in turn, reduces the pressure to clear for grazing land or produce the grains and grasses (more farming, more fertilizer) required to feed them.

"We're not saying these diets have to be vegetarian or vegan," Tilman said. Widespread reduction of red meat consumption to once a week and having protein come from other sources such as chicken or fish, while increasing fruits and vegetables, in conjunction with decreasing fossil fuel use, could help keep the planet livably cool in the long run.

Another strategy: ease up on fertilizer.

"Many countries have high yields because from 1960 until now they have been using more and more fertilizer," he said. "But recent research has shown that almost all of these countries are actually using much more than they need to attain the yield they have." A drop of roughly 30% in fertilizer use would not only save the farmer money for the same yield, it prevents the release of nitrous oxide that occurs when excess fertilizer goes unused.

"About 40% of all future climate warming from agriculture may come from nitrous oxide from fertilizer," Tilman added. "So adding the right amount of fertilizer has a large benefit for climate change and would save farmers money."

Other strategies the researchers explored included adjusting global per capita calorie consumption to healthy levels; improving yields to help meet demand where it may reduce the pressure to clear more land; and reducing food waste by half.

"The nice thing is that we can do each of these things sort of halfway and still solve the problem," Tilman said. The sooner we employ these strategies, the closer we can get to keeping the Earth cool and avoiding the wholesale changes we would have to adopt if we wait too much longer, he added.

"I'm optimistic," he said. "We have a viable path for achieving global environmental sustainability and better lives for all of us."

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Ecologically friendly agriculture doesn't compromise crop yields

Increasing diversity in crop production benefits biodiversity without compromising yields, according to an international study examining diversified and simplified agricultural practices.

UNIVERSITY OF BRITISH COLUMBIA

Research News

 

IMAGE: INCREASING DIVERSITY IN CROP PRODUCTION BENEFITS BIODIVERSITY WITHOUT COMPROMISING CROP YIELDS, ACCORDING TO NEW RESEARCH. view more 

CREDIT: JAMIL RHAJIAK / UNIVERSITY OF BRITISH COLUMBIA, COMMUNICATIONS & MARKETING.

Increasing diversity in crop production benefits biodiversity without compromising crop yields, according to an international study comparing 42,000 examples of diversified and simplified agricultural practices.

Diversification includes practices such as growing multiple crops in rotation, planting flower strips, reducing tillage, adding organic amendments that enrich soil life, and establishing or restoring species-rich habitat in the landscape surrounding the crop field.

"The trend is that we're simplifying major cropping systems worldwide," says Giovanni Tamburini at the Swedish University of Agricultural Sciences and lead author of the study. "We grow monoculture on enlarged fields in homogenized landscapes. According to our study diversification can reverse the negative impacts that we observe in simplified forms of cropping on the environment and on production itself."

The research, published in Science Advances, is based on 5,188 studies with 41,946 comparisons between diversified and simplified agricultural practices. Crop yield was in general maintained at the same level or even increased under diversified practices. The enhanced biodiversity benefited pollination and pest regulation by natural predation. It also improved water regulation and preserved soil fertility. Diversification, however, had variable effects on climate regulation. In some cases, it increased greenhouse gas emissions.

"By bringing together so much data, this work powerfully shows the potential for diversified farming to maintain productivity while reducing environmental harms and sustaining biodiversity and ecosystem services," says Claire Kremen at the University of British Columbia and co-author of the study.

"However, we need to tune these techniques to specific crops and regions, maximize these benefits and reduce trade-offs that otherwise occur. Much more investment is needed to support adoption of diversified farming practices, through research, management incentives and extension programs."

Increasing biodiversity is assumed to enhance yields and ecosystem services such as pollination, pest regulation by natural enemies, nutrient turnover, water quality and climate change mitigation by carbon sequestration. Although much research has been invested to explore this, outcomes of diversification had not previously been synthesized. Further, the focus had mainly been diversification of crops and vegetation. Diversification of soil organisms is seldom recognized.

"An important next step is to identify which practices and conditions that result in positive or negative climate mitigation, and to avoid practices that give negative impacts," says Sara Hallin at the Swedish University of Agricultural Sciences and co-author of the study.

Studies where yield had been examined together with one or more other ecosystem services were few but still many enough to analyze occurrence of win-win, trade-off and lose-lose situations. Win-win outcomes between yield and another service dominated with 63 % of the cases, but all other possible outcomes (i.e. representing tradeoffs between yield and ecosystem services) were also represented.

Many of the tested diversification practices are in use already today, but can be more widely adopted and combined both on and off the crop field.

How can we diversify our farming systems?

There are many ways to increase diversity both on and off the crop field. Farms can add crop species to crop rotations, or grow crops together in the same field with intercropping. Flowering crops provide pollen and nectar for pollinating and predatory insects. Farms can also support below-ground biodiversity by mulching crop residues and adding manure or minimizing soil disturbance by reducing tillage.

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Climate change and food demand could shrink species' habitats by almost a quarter by 2100

UNIVERSITY OF CAMBRIDGE

Research News

 

Mammals, birds and amphibians worldwide have lost on average 18% of their natural habitat range as a result of changes in land use and climate change, a new study has found. In a worst-case scenario this loss could increase to 23% over the next 80 years.

The study, published today in the journal Nature Communications, analysed changes in the geographical range of 16,919 species from 1700 to the present day. The data were also used to predict future changes up to the year 2100 under 16 different climate and socio-economic scenarios.

A diverse abundance of species underpins essential ecosystem functions from pest regulation to carbon storage. Species' vulnerability to extinction is strongly impacted by their geographical range size, and devising effective conservation strategies requires a better understanding of how ranges have changed in the past, and how they will change under alternative future scenarios.

"The habitat size of almost all known birds, mammals and amphibians is shrinking, primarily because of land conversion by humans as we continue to expand our agricultural and urban areas," said Dr Robert Beyer in the University of Cambridge's Department of Zoology, first author of the report.

Some species are more heavily impacted than others. A worrying 16% of species have lost over half their estimated natural historical range, a figure that could rise to 26% by the end of the century.

Species' geographical ranges were found to have recently shrunk most significantly in tropical areas. Until around 50 years ago, most agricultural development was in Europe and North America. Since then, large areas of land have been converted for agriculture in the tropics: clearance of rainforest for oil palm plantations in South East Asia, and for pasture land in South America, for example.

As humans move their activities deeper into the tropics, the effect on species ranges is becoming disproportionately larger because of a greater species richness in these areas, and because the natural ranges of these species are smaller to begin with.

"The tropics are biodiversity hotspots with lots of small-range species. If one hectare of tropical forest is converted to agricultural land, a lot more species lose larger proportions of their home than in places like Europe," said Beyer.

The results predict that climate change will have an increasing impact on species' geographical ranges. Rising temperatures and changing rainfall patterns will alter habitats significantly, for example: other studies have predicted that without climate action, large parts of the Amazon may change from canopy rainforest to a savannah-like mix of woodland and open grassland in the next 100 years.

"Species in the Amazon have adapted to living in a tropical rainforest. If climate change causes this ecosystem to change, many of those species won't be able to survive - or they will at least be pushed into smaller areas of remaining rainforest," said Beyer.

He added: "We found that the higher the carbon emissions, the worse it gets for most species in terms of habitat loss."

The results provide quantitative support for policy measures aiming at limiting the global area of agricultural land - for example by sustainably intensifying food production, encouraging dietary shifts towards eating less meat, and stabilising population growth.

The conversion of natural vegetation to agricultural and urban land, and the transformation of suitable habitat caused by climate change are major causes of the decline in range sizes, and two of the most important threats to global terrestrial biodiversity.

"Whether these past trends in habitat range losses will reverse, continue, or accelerate will depend on future global carbon emissions and societal choices in the coming years and decades," Professor Andrea Manica in the University of Cambridge's Department of Zoology, who led the study.

He added: "While our study quantifies the drastic consequences for species' ranges if global land use and climate change are left unchecked, they also demonstrate the tremendous potential of timely and concerted policy action for halting - and indeed partially reversing - previous trends in global range contractions. It all depends on what we do next."

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Decrease in fossil-fuel CO2 emissions due to COVID-19 detected by atmospheric observations

Synoptic CO2 variations decreased at Hateruma Island, Japan, during February-March 2020

NATIONAL INSTITUTE FOR ENVIRONMENTAL STUDIES

Research News

 

IMAGE: BIRDS-EYE VIEW PHOTO OF HATERUMA ISLAND (LEFT) AND THE MONITORING STATION ON THE ISLAND (RIGHT). view more 

CREDIT: NIES

Tracking emissions of anthropogenic greenhouse gases by atmospheric observations is a major challenge for policymaking, such as the Paris Agreement. Huge atmospheric observation networks comprised of a variety of platforms including satellites have been developed to monitor regional/country-scale changes in the anthropogenic greenhouse gas emissions. The outbreak of the new coronavirus (COVID-19) has been affecting the global socio-economic activity, leading to a significant reduction in fossil-fuel-derived CO2 (FFCO2) emissions and other anthropogenic air pollutants in the world. This situation gave us a unique opportunity to assess our ability to quantify the changes in the regional FFCO2 emissions using atmospheric observations. However, there are few reports of observational evidence for CO2 emission reduction due to the COVID-19 lockdown, although a large number of publications have reported reductions in short-lived air pollutants from various parts of the world.

In Scientific Reports by Nature Publishing, researchers from the National Institute for Environmental Studies (NIES), Japan, and the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) analyzed atmospheric CO2 and CH4 concentrations observed at Hateruma Island, Japan, which is located in the continental margin of East Asia, and detected signals related to the FFCO2 reduction in China caused by the restrictions associated with the COVID-19 outbreak in January-March 2020.

We estimated that the FFCO2 emissions decreased by about 20% during January-February 2020 as a result of the measures to prevent the spread of COVID-19 within China and to the outside world. While a significant reduction of the atmospheric pollutants has been reported, papers on the atmospheric signals of the FFCO2 reduction are yet to be found in the published literature. "The size of the atmospheric reservoir of CO2 is quite large and the atmospheric CO2 has a relatively long lifetime. These characteristics make the change in the atmospheric CO2 concentrations caused by the COVID-19 influence quite small", stated Prabir K. Patra, co-author of the study and researcher at JAMSTEC.

To detect such faint signals in the CO2 variations, the research team of NIES and JAMSTEC focused on the relative variation of the atmospheric CO2 and CH4 observed at Hateruma Island for the past 20 years at daily time intervals. "The atmospheric observation at Hateruma Island is often influenced by the continental emissions during winter due to the airflow pattern caused by the East Asian monsoon. We know that the temporal variations in the atmospheric CO2 and CH4 concentrations show considerable similarity, and the temporal change in the ratio of CO2 to CH4 variations trace very well the temporal change in fossil-fuel emissions in China for the years before 2020", said Yasunori Tohjima, lead author of the study and researcher at NIES. "Thus the variation ratio of CO2 to CH4 was expected to detect the signal reflecting the change in the continental CO2 emissions related to COVID-19 restrictions."

The research team found that the monthly average ratio of the atmospheric CO2 to CH4 variations in January, February, and March tracked the yearly increase in FFCO2 emissions from China during 1997-2019. However, the ratios showed significant decreases in February and March 2020, which coincided with the lockdown period in China. "The relationship between the variation ratio and the FFCO2 emissions from China should be evaluated by using an atmospheric transport model and a set of CO2 and CH4 flux maps", said Yosuke Niwa, co-author of the study and researcher at NIES. "We used multiple simulations of atmospheric CO2 and CH4 at Hateruma Island for various emission reduction scenarios of fossil-fuel CO2 by using NICAM-TM." The study thus concluded that China's FFCO2 emissions decreased by about 30% in February and about 20% in March 2020. "Our approach presented in this study has the potential to detect signals from the emission reduction from any specific region in near-real-time using continuous and high-precision measurements of CO2 and CH4", mentioned Prabir K. Patra.

CAPTION

Temporal change in monthly averages of the variation ratio of the atmospheric CO2 to CH4 in January, February, and March observed at Hateruma Island since 1998. The grey thick line represents the smoothed trend curve, and the grey-shaded area represents the 95% range of the variations from the trend curve. The black solid, broken, and dotted lines are the estimated fossil-fuel-related CO2 emissions from China.

Plastics and rising CO2 levels could pose combined threat to marine environment

UNIVERSITY OF PLYMOUTH

Research News

 

The combined environmental threat of plastic pollution and ocean acidification are having significant impacts on species living in our oceans, according to new research.

An international team of scientists found that after three weeks of being submerged in the ocean, the bacterial diversity on plastic bottles was twice as great as on samples collected from the surrounding seawater.

However, in areas of elevated carbon dioxide, a large number of taxonomic groups - including bacteria that play an important role in carbon cycling - were negatively impacted.

Conversely, other species - including those have previously been shown to thrive in areas of high ocean plastics and to potentially cause disease on coral reefs - were enriched by it.

The research also showed that while many groups of bacteria were shared between plastic, free-living and particle-associated samples, almost 350 were found uniquely on plastics.

Writing in the journal Marine Pollution Bulletin, researchers say the study adds to growing evidence that the increasing presence of plastic marine debris is providing a novel habitat for bacteria.

However, their results highlight that environmental conditions and local ecological processes will play an important role in determining its broader impact over the coming decades.

The study was led by the University of Tsukuba (Japan) and the University of Plymouth (UK), in collaboration with Keimyung University (Korea), Kyungpook National University (Korea) and Nanjing University (China).

Scientists submerged a number of plastic bottles in seas off the Japanese Island of Shikine, a region renowned for its CO2 seeps where the escaping gas dissolves into the sea water and creates conditions similar to that expected to occur worldwide in coming years.

They then used a combination of DNA sequencing and statistical techniques to analyse how bacteria colonise the plastic in comparison to the surrounding natural environment, and whether the increased CO2 levels would cause changes in the bacteria's distribution.

Lead author Dr Ben Harvey, Assistant Professor at the University of Tsukuba's Shimoda Marine Research Center and a graduate of the BSc (Hons) Ocean Science programme in Plymouth, said: "Discarded plastic drinking bottles have become a common sight in our oceans and we were expecting to see them being colonised by different types of bacteria. We also predicted that raised CO2 levels would cause significant changes in the bacterial colonies, but it was still surprising to see the extent of that change and how the raised levels affected species differently. To see beneficial species dwindling while harmful species thrive is an obvious present and future cause for concern."

Researchers from Tsukuba, Plymouth and other collaborators have published several studies over the past decade showing the threats posed by ocean acidification in terms of habitat degradation and a loss of biodiversity.

It is also the latest research by the University of Plymouth into plastics, with it being awarded a Queen's Anniversary Prize for Higher and Further Education in 2020 for its ground-breaking research and policy impact on microplastics pollution in the oceans.

Jason Hall-Spencer, Professor of Marine Biology at the University of Plymouth and senior author on the study, added: "Up to 13 million tons of plastics from land end up in the oceans each year and they have been shown to affect all types and sizes of marine species. Combine that with rising CO2 levels and the threat posed to the global ocean is stark. It reinforces the importance of taking steps to meet the standards demanded by international climate treaties so as to reduce the impact of ocean acidification and warming. It is also within our power to change cultures so that litter created on land does not become an environmental hazard in our oceans, both now and for future generations."

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