Researchers complete first comprehensive threat assessment of all U.S. trees

For the first time, researchers have completed threat assessments for all 881 native tree species in the contiguous United States, resulting in a comprehensive checklist and synthesis that will serve as a critical baseline to guide future tree conservation efforts.

The new assessment of U.S. trees reveals that 11-16% of tree species in the contiguous 48 U.S. states are threatened with extinction, with the most common threat being invasive and problematic pests and diseases. According to Abby Meyer, executive director of Botanic Gardens Conservation International-U.S. (BGCI-US), a partner on the project, "These results lay the groundwork for U.S. tree and ecosystem conservation efforts that will contribute to achieving critical international conservation goals, including the United Nations Decade for Ecosystem Restoration and the Global Tree Assessment."

Murphy Westwood, Ph.D., vice president of science and conservation at The Morton Arboretum and senior author of the report, noted that much of the world's biodiversity depends on trees, which offer food and habitat for countless plant, animal and fungal species while providing invaluable benefits to humans. "Understanding the current state of trees within the U.S. is imperative to protecting those species, their habitats and the countless communities they support," she said.

The report, available through early access online, will be published in an upcoming special issue of Plants, People, Planet highlighting this and other projects of the Global Tree Assessment initiative. This study is the culmination of five years of research conducted by BGCI-US, The Morton Arboretum and NatureServe, in partnership with the United States Botanic Garden (USBG) and United States Department of Agriculture (USDA) Forest Service.

Researchers examined the extinction risk, patterns of geographic and taxonomic diversity and leading threats facing tree species native to the continental U.S. Most U.S. species had never been assessed or were outdated on the two most widely used threat assessment platforms, the International Union for Conservation of Nature (IUCN) Red List and NatureServe.

"This assessment advances our understanding of the threats faced by America's native trees and will help focus the conservation efforts of public gardens, federal agencies and conservation organizations," said Susan Pell, Ph.D., acting executive director of USBG. "The U.S. Botanic Garden is proud to sponsor national partnerships such as this that advance plant conservation."

"Trees form the basis of many of the world's terrestrial ecosystems," said Sean T. O'Brien, Ph.D., president and CEO of NatureServe. "Understanding what trees are threatened and why is critical to informing conservation for trees and ecosystems across the nation."

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The authors built the checklist based on the standardized Global Tree Assessment definition of a tree: a woody plant with usually a single stem, growing to a height of at least two meters; or if multi-stemmed, then at least one vertical stem five centimeters in diameter at breast height. Based on this definition, the checklist of trees native to the contiguous U.S. contains 881 species.

Oaks (genus Quercus) and hawthorns (genus Crataegus) dominate the tree flora of the U.S., with 85 and 84 native species, respectively. Hawthorns and oaks were also found to have the most threatened species, with 29 and 17 species, respectively.

The research found that geographically, the distribution of native (plants that evolved in the contiguous U.S.) and endemic (plants found only in the contiguous U.S.) trees is primarily concentrated in the southeastern U.S., California and Texas. Florida and Texas have the highest number of native tree species, with 342 and 321, respectively. Florida and California have the highest number of threatened tree species, with 45 and 44, respectively.

According to BGCI's PlantSearch database of plants in botanical collections, 95% (849) of native U.S. tree species are located in at least one ex-situ (outside natural locations) collection, such as a botanic garden, arboretum or seed bank. Most species are represented in dozens or even hundreds of collections, such as Franklinia alatamaha, which is extinct in the wild. However, 17 threatened tree species are not currently conserved in any ex-situ collection and thus have no insurance policy against extinction.

The checklist and synthesis of U.S. trees is the culmination of a project that began in 2017, when BGCI-US, The Morton Arboretum, NatureServe, USBG and the USDA Forest Service began efforts to assess the threats to all U.S. trees. The authors also established a data sharing methodology for future updates to improve efficiency and conservation collaboration to protect U.S. trees.

"Through initiatives like the Global Tree Assessment, tree research and conservation has evolved from a series of small individual efforts to a global venture grounded in collaborative, scientifically-backed strategies," said Westwood. "The checklist is a major milestone for trees, but most importantly, our hope is that this study will inform and amplify the scope of tree conservation efforts across the country," she added.

The checklist of U.S. trees is available on The Morton Arboretum's website: https://mortonarb.org/science/projects/data-sharing-for-conservation-us-trees/

#Nature | https://sciencespies.com/nature/researchers-complete-first-comprehensive-threat-assessment-of-all-u-s-trees/

Is Cricket Sustainable Amid Climate Change?

The joke is that if you want it to rain during this wetter-than-usual summer in the Caribbean, just start a cricket match.

Beneath the humor is seemingly tacit agreement with the assertion in a 2018 climate report that of all the major outdoor sports that rely on fields, or pitches, “cricket will be hardest hit by climate change.”

By some measures, cricket is the world’s second most popular sport, behind soccer, with two billion to three billion fans. And it is most widely embraced in countries like India, Pakistan, Sri Lanka, Bangladesh and South Africa and in the West Indies, which are also among the places most vulnerable to the intense heat, rain, flooding, drought, hurricanes, wildfires and sea level rise linked to human-caused emissions of greenhouse gases.

Cricket in developed nations like England and Australia has also been affected as heat waves become hotter, more frequent and longer lasting. Warm air can hold more moisture, resulting in heavier rainstorms. Twenty of the 21 warmest years recorded have occurred since 2000.

This year, the sport has faced the hottest spring on the Indian subcontinent in more than a century of record keeping and the hottest day ever in Britain. In June, when the West Indies — a combined team from mainly English-speaking countries in the Caribbean — arrived to play three matches in Multan, Pakistan, the temperature reached 111 degrees Fahrenheit, above average even for one of the hottest places on earth.

“It honestly felt like you were opening an oven,” said Akeal Hosein, 29, of the West Indies, who with his teammates wore ice vests during breaks in play.

South Africa cricketers took a water break during a match against India at Arun Jaitley Stadium in New Delhi in June. This has been the hottest spring on the Indian subcontinent in more than a century of record keeping.Anindito Mukherjee for The New York Times

India’s Shreyas Iyer in action during the match. To cope with the heat, some players have worn ice vests during breaks in play.Anindito Mukherjee for The New York Times

Heat is hardly the only concern for cricket players. Like the roughly similar pitching and batting sport of baseball, cricket cannot easily be played in the rain. In July, the West Indies abandoned a match in Dominica and shortened others in Guyana and Trinidad because of rain and waterlogged fields.

An eight-match series between the West Indies and India concludes Saturday and Sunday in South Florida as the height of hurricane season approaches in the Gulf and the Atlantic. In 2017, two Category 5 storms, Irma and Maria, damaged cricket stadiums in five countries in the Caribbean.

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Matches can last up to five days. Even one-day matches can extend in blistering conditions for seven hours or more. While rain cleared July 22 for the 9:30 a.m. opening of the West Indies-India series in Port of Spain, Trinidad and Tobago, players still had to contend with eight hours of sun at Queen’s Park Oval in temperatures that reached the low 90s with 60-plus percent humidity.

According to a 2019 report on cricket and climate change, a professional batsman playing over a day can generate heat equivalent to running a marathon. While marathon runners help dissipate heat by wearing shorts and singlets, in cricket the wearing of pads, gloves and a helmet restricts the ability to evaporate sweat in hot, humid conditions often lacking shade.

“It’s pretty evident that travel plans are being disrupted because of weather conditions, along with the scheduling of matches, because of rainfall, smoke, pollution, dust and heat,” said Daren Ganga, 43, a commentator and former West Indies captain who studies the impact of climate change on sport in affiliation with the University of the West Indies.

“Action needs to be taken for us to manage this situation,” Ganga said, “because I think we’ve gone beyond the tipping point in some areas. We still have the opportunity to pull things back in other areas.”

The International Cricket Council, the sport’s governing body, has not yet signed on to a United Nations sports and climate initiative. Its goal is for global sports organizations to reduce their carbon footprint to net-zero emissions by 2050 and to inspire the public to consider the issue urgently. While Australia has implemented heat guidelines, and more water breaks are generally permitted during matches, there is no global policy for play in extreme weather. The cricket council did not respond to a request for comment.

“This is like stick your head in the sand denial,” David Goldblatt, the British author of a 2020 report on sport and climate change, said of the council. “Cricket really needs to get its act together. A whole bunch of trouble is not really far away.”

A suggestion in the 2019 climate report that players be allowed to wear shorts instead of trousers to keep cool in excessive heat may seem like a common-sense idea. But it has not gone over well with the starchy customs of international cricket or seemingly with many players, who say their legs would be even more susceptible to brush burns and bruises from sliding and diving on hard fields.

A spectator stood next to a mist fan and wiped sweat off his face. Matches can last for days, testing both fans and players.Anindito Mukherjee for The New York Times

In July, cricket fans sat in the sun in Durham, England, to watch a match between England and South Africa. Oli Scarff/Agence France-Presse — Getty Images

“My two knees are already gone,” said India’s Yuzvendra Chahal, who is 32.

Still, questions are being raised inside the sport and out about the sustainability of cricket amid the extremes of climate and the exhausting scheduling of various formats of the game. The English star Ben Stokes retired on July 19 from the one-day international format, saying, “We are not cars where you can fill us up with petrol and let us go.”

Coincidentally, Stokes’s retirement came as Britain recorded its hottest day ever, with temperatures rising for the first time above 40 degrees Celsius, or 104 degrees Fahrenheit. As climate scientists said such heat could become the new normal, England hosted a daylong cricket match with South Africa in the modestly cooler northeastern city of Durham. Extra water breaks, ice packs and beach-style umbrellas were employed to keep the players cool. Even with those precautions, Matthew Potts of England left the match, exhausted.

Aiden Markram of South Africa was photographed with an ice bag on his head and another on his neck, his face in apparent distress, as if he had been in a heavyweight fight. Some fans were reported to have fainted or sought medical attention, while many others scrambled for thin slices of shade.

On June 9, South Africa also endured taxing conditions when it faced India in the heat, humidity and pollution of New Delhi. The heat index was 110 degrees Fahrenheit for an evening match. A section of the stadium was transformed into a cooling zone for spectators, with curtains, chairs and misting fans attached to plastic tubs of water.

“We are used to it,” said Shikhar Dhawan, 36, one of India’s captains. “I don’t really focus on the heat because if I start thinking about it too much I will start feeling it more.”

In India, cricket players are as popular as Bollywood actors. Even in sauna-like conditions, more than 30,000 spectators attended the match in New Delhi. “It feels great. Who cares about the heat?” said Saksham Mehndiratta, 17, attending his first match with his father since the coronavirus pandemic began.

After watching some spectacular batting, his father, Naresh, said, “This chills me down.”

South Africa, though, was taking no chances after a tour of India in 2015, when eight players and two members of the coaching and support staff were hospitalized in the southern city of Chennai by what officials said were the combined effects of food poisoning and heat exhaustion.

A staff member refilled water bottles for spectators at the match at the Riverside cricket ground in Durham, England. Oli Scarff/Agence France-Presse — Getty Images

England’s Ben Stokes walked past his teammate Jos Buttler after losing his wicket.Lee Smith/Action Images Via Reuters

“It was mayhem,” said Craig Govender, a physiotherapist for the South African team.

For South Africa’s recent tour, Govender took along inflatable tubs to cool players’ feet; electrolyte capsules for mealtimes; slushies of ice and magnesium; and ice towels for the shoulders, face and back. South Africa’s uniforms were ventilated behind the knees, along the seams and under the armpits. Players were weighed before and after training sessions. The color of their urine was monitored to guard against dehydration. During the June 9 match, some players jumped into ice baths to cool down.

“Global warming is already wreaking havoc on our sport,” Pat Cummins, the captain of Australia’s test cricket team, which plays five-day matches, wrote in February in The Guardian newspaper of Britain.

In 2017, Sri Lankan players wore masks and had oxygen canisters available in the dressing room to counter the heavy pollution during a match in New Delhi. Some players vomited on the field.

In 2018, the English captain Joe Root was hospitalized with gastrointestinal issues, severe dehydration and heat stress during the famed, five-day Ashes test in Sydney, Australia. At one point, a heat-index tracker registered 57.6 degrees Celsius, or 135.7 Fahrenheit.

The incident led Tony Irish, then the head of the Federation of International Cricketers’ Association, to ask, “What will it take — a player to collapse on the field?” before cricket’s governing body implemented an extreme heat policy.

Also in 2018, India’s players were asked to limit showers to two minutes while playing in Cape Town during an extended drought there that caused the cancellation of club and school cricket.

In 2019, the air in Sydney became so smoky during a bush fire crisis that the Australian player Steve O’Keefe said it felt like “smoking 80 cigarettes a day.”

Climate change has touched every aspect of cricket from batting and bowling strategy to concerns by groundskeepers about seed germination, pests and fungal disease. Even Lord’s, the venerable cricket ground in London, has been forced at times to relax its fusty dress code, most recently in mid-July when patrons were not required to wear jackets in the unprecedented heat.

India’s Hardik Pandya paused for a drink during practice before a match. Climate change has touched every aspect of the sport, from the care of the pitch to the spectator dress code at matches.Anindito Mukherjee for The New York Times

Children played cricket in New Delhi in June. Because of global warming, “our love and appetite for sport risks straying into brutality,” said Russell Seymour of Lord’s Cricket Ground in London.Anindito Mukherjee for The New York Times

Athletes are being asked “to compete in environments that are becoming too hostile to human physiology,” Russell Seymour, a pioneer in sustainability at Lord’s, wrote last year in a climate report. “Our love and appetite for sport risks straying into brutality.”

To be fair, some actions have been taken to help mitigate climate change. Matches sometimes start later in the day or are rescheduled. Cummins, the Australian captain, has begun an initiative to have solar panels installed on the roofs of cricket clubs there. Lord’s operates fully on wind-powered electricity. The National Green Tribunal of India, a specialized body that addresses environmental concerns, has ruled that treated waste water should be used to irrigate cricket fields instead of drinkable ground water, which is in short supply.

Players on the Royal Challengers Bangalore club of the Indian Premier League wear green uniforms for some matches to heighten environmental awareness. Team members appeared in a climate video during a devastating heat wave this spring, which included this sobering fact: “This has been the hottest temperature the country has faced in 122 years.”

Yet some in the cricket world counter that climate change cannot be expected to be the most immediate concern in developing nations, where the basics of daily life can be a struggle. And countries like India and Pakistan, where cricket is wildly popular, are among the least responsible for climate change. One hears the frequent admonishment that rich, developed nations that emit the largest amount of greenhouse gases must also do their share to lower those emissions.

“In the U.S., people are flying on private jets while they’re asking us not to use plastic straws,” said Dario Barthley, a spokesman for the West Indies team.

Kitty Bennett contributed research.

#Environment | https://sciencespies.com/environment/is-cricket-sustainable-amid-climate-change/

How Coal Mining and Years of Neglect Left Kentucky Towns at the Mercy of Flooding

The region, one of the poorest in the country, is full of modest, unprotected homes and decaying infrastructure. Some residents say they won’t return.

FLEMING-NEON, Ky. — This sliver of land wedged between the thick woods and Wright Fork creek has been the home of Gary Moore’s family for as long as there has been a United States. The burial plot for an ancestor who fought in the Revolutionary War, he said, is a mile away. Mr. Moore himself lives in a mobile home across from his father’s house; the house where his grandmother lived is next door.

All of that was wrecked in last week’s flooding.

“This is kind of like the final straw,” Mr. Moore, 50, said as he looked out at a new terrain of shredded homes, crushed cars and endless debris. “We’re gradually losing it — that bond we had. It’s slipping away. People are getting out of here, trying to get better jobs and live better lives. I’m leaning in that direction myself.”

For much of the last century, the country was powered by the labor of coal miners underneath the hills and mountains of southeastern Kentucky. But the landscape that was built to serve this work was fragile, leaving the people here extraordinarily vulnerable, especially after the coal industry shuttered so many of the mines and moved on. What remained were modest, unprotected homes and decaying infrastructure, and a land that itself, in many places, had been shorn of its natural defenses.

Last week, when a deluge of rain poured into the hollows, turning creeks into roaring rivers, overwhelming old flood records, killing at least 37 people and destroying countless homes, that vulnerability was made brutally manifest.

“When you have a century of billions of dollars and resources leaving, very little of it staying to create the infrastructure necessary for people to live lives, and it’s neglected as long as it has been,” said Wes Addington, a lawyer with the Appalachian Citizens Law Center in nearby Whitesburg, whose law office is now a flooded wreck, “when that’s combined with a really insane flood, it’s a catastrophe.”

In the heyday of coal, Fleming-Neon was full of restaurants and stores, a movie theater and an Oldsmobile dealership.Jon Cherry for The New York Times

A storefront that was heavily damaged by flash floods in Fleming-Neon.Jon Cherry for The New York Times

Southeastern Kentucky, which includes some of the poorest counties in the country, is different from many other rural areas, which have populated county seats surrounded by mostly empty countryside. Here, tiny communities are scattered all over the mountains, little clusters of shotgun houses and mobile homes lining creeks and hollows for miles. Many of these were once coal company camps, said Mr. Addington, who grew up in one. They were built for miners a hundred years ago, and often named — like the Fleming in Fleming-Neon — for coal company executives.

Work in the mines was always grueling, but in the heyday of coal, it made for a glittering strand of little mountain boom towns. Fleming-Neon was once one, full of restaurants and stores, a movie theater and an Oldsmobile dealership.

“When I was in high school, we had businesses up and down through here,” Mr. Moore recalled, gesturing atstorefronts that had been sitting gloomily empty well before the waters came through.

In Letcher County, where Fleming-Neon is, the number of people working in the mines is down about 95 percent from what it was in 1990; the county itself, now with 21,000 people, has shrunk by about a fifth since then.

The departure of coal companies left a population dispersed in small communities throughout the mountains, stretching water lines, roads and other vital infrastructure delicately thin. With the gradual disappearance of coal came a dramatic reduction in tax revenue, leaving much of this infrastructure crumbling long before the flood. For a population that is older, poorer and in worse health than much of the country, and thus heavily reliant on social and health services, this had already been a crisis.

“This is kind of like the final straw,” said Gary Moore, 50, whose home in Fleming-Neon was wrecked in last week’s flooding.Jon Cherry for The New York Times

The gradual disappearance of coal mining in Letcher County, Ky., brought a dramatic reduction in tax revenue, leaving much of its infrastructure crumbling long before the flood.Jon Cherry for The New York Times

Many former miners, their bodies and lungs broken and poisoned from years of arduous work underground, were never able to find another dependable line of work; fewer than half of the adults in Letcher County are in the labor force, and more than a quarter of people under 65 report having a disability. The median household income is about half of the national. The median home valueis just $54,700.

“It’s hard, it’s really hard,” said Kathy Arnett, 40, who was raised in a hollow not far from Fleming-Neon. “They just don’t make no effort to put nothing in here to help our families.”

Ms. Arnett spoke about the difficulty finding much of anything around here, most of all a good job. It was poisonous to the young, she said, the sense of futility that can set in.

“I hold our presidents — not one, all of them — responsible,” she said. “They should have been trying sooner.”

Government oversight meant to ensure the safety of homes is weaker here than in other parts of the country. In much of Kentucky, there is no enforcement mechanism for building codes for single-family homes, said Corey Roblee, vice president for government relations at the International Code Council, a group that oversees the development of building standards. Those codes are meant to protect structures against threats like flooding. Letcher County, as well as some of the other counties hit hardest by the flooding, has no local building inspector at all, according to state records.

Still, building codes apply primarily to new construction, and there is not much of that these days. In 2021, not a single building permit was issued in the county, census data show. Of the 10,500 homes that were in Letcher County on the eve of the flood, fewer than 120 had flood insurance, according to FEMA records. In the city of Fleming-Neon, only one property did.

Appalshop, an arts and cultural organization in Whitesburg, Ky., was badly damaged in the floods.Jon Cherry for The New York Times

A home damaged by flash flooding in Fleming-Neon.Jon Cherry for The New York Times

When last week’s storms arrived, they rolled into a mountainous topography “exceptionally susceptible to heavy rain events,” said Matthew Eby, chief executive officer of the First Street Foundation, a New York-based group that maps flood risks. According to First Street’s data, two-thirds of the homes in Letcher County face a high risk of flooding, as does most of the county’s critical infrastructure, such as fire stations and schools.

And as temperatures rise over time, a consequence of the burning of coal dug out of these very mountains, warmer air is able to hold more moisture, making it possible for more rain to fall more quickly.

The land itself has changed over the decades, too, as coal companies stripped away hillsides or blew the tops off mountains to get at the riches underneath. Researchers have found that the treeless land that is left behind, if not carefully restored, can increase the speed and volume of rain runoff, worsening floods in the mountains.

“Ten, twelve years ago most of my practice was representing flood victims below unreclaimed strip mines,” said Ned Pillersdorf, a lawyer in nearby Floyd County, which was also hard hit in the floods. It was hard to say at this point precisely how much that played a part in last week’s flooding, he said. But he added: “Fly over here and see how many unreclaimed strip-mines are still out there.”

This week, the people in the region were working long, exhausting days, clearing debris with backhoes, cooking meals for one another, handing out jugs of water, building makeshift bridges and offering shelter to newly homeless neighbors.

But the work ahead was almost unfathomably daunting. Across the region, little communities remained isolated on the other side of washed-out bridges, thousands were enduring a boiling summer heat without electricity and thousands more were cut off from water. Emergency responders were still searching the wreckage in the remote valleys, as officials warned that an already grim death toll was likely to rise.

Civilians and National Guardsmen unloaded supplies from a UH-60 Blackhawk in Fleming-Neon.Jon Cherry for The New York Times

Bill Rose, 64, outside the mechanic shop in Fleming-Neon where he and his brother like to tinker on old cars. He said he was committed to rebuilding, however long it took.Jon Cherry for The New York Times

Zach Weinberg lives a few hundred yards from a family who lost four children to the floodwaters. In recent days, he has been traveling from home to home in Knott County to replace flood-damaged gas meters for his family-run business. Some customers have told him not to bother, he said. They are not coming back.

More people will probably be making this decision when they realize how long and arduous the recovery will be, Mr. Weinberg said. And when they go, they will take tax revenue with them, leaving cash-strapped local governments with even less.

“It’ll be a partial government that does what they can, which won’t be much,” Mr. Weinberg said.

There are people and groups throughout the mountains — like Appalshop, the arts and cultural organization in Whitesburg that was badly damaged in the floods — that have been working for years to remake eastern Kentucky into a flourishing region that is no longer dependent on coal mines. The Kentucky governor, Andy Beshear, is already talking with lawmakers about a substantial flood relief package, and the FEMA administrator has pledged to assist in the recovery “as long as you need us.”

But unless Congress provides additional money for people to rebuild or replace their homes — a process that can take years, if it happens at all — many flood victims will have to rely on savings, charity or whatever other help they can find. And many are asking how much there is left to preserve.

On Tuesday, Bill Rose, 64, was slowly shoveling away the mounds of mud outside the mechanic shop in Fleming-Neon where he and his brother like to tinker on old cars. Like so many others, he talked about the resilience people must have to live here. He said he was committed to staying.

“You build back,” he said.

But he made clear he was talking about himself. Not his children.

He was grateful when his daughter left for work as a nurse closer to Louisville, Ky. She loved it here but there was nothing for her — no jobs, no opportunities, nothing to do. After the cataclysm of last week, there was even less.

“My generation,” Mr. Rose said, “will probably be the last generation.”

Storm clouds over Fleming-Neon.Jon Cherry for The New York Times

#Environment | https://sciencespies.com/environment/how-coal-mining-and-years-of-neglect-left-kentucky-towns-at-the-mercy-of-flooding/

The Cartwheel Galaxy Is the Webb Telescope’s Latest Cosmic Snapshot

Scientists gained new insights into the distant object, which got its distinctive shape from a collision with another galaxy.

Scientists on Tuesday published the latest images from NASA’s triumphant James Webb Space Telescope. The newest release documents the Cartwheel galaxy, which is about 500 million light-years from our planet and is aptly named for its wheel-like appearance, complete with a center hub, a tire and even wavy, fluorescent spokes. The Webb also recorded two smaller companion galaxies alongside Cartwheel.

The new images come on the heels of NASA’s July 12 unveiling of five initial scenes captured by the Webb telescope, the most powerful space observatory built to date. Since they were launched on Dec. 25, the Webb’s 18 hexagonal gold mirrors have aligned to capture other targets in space, though not all images have been released. Snapshots have included the Southern Ring nebula, which resembles a soap bubble expanding from a dead star, and the striking Carina nebula, composed of swirling dust akin to jagged cliffs.

Astronomers have been studying the Cartwheel galaxy for decades. Initially, it was inspected from two ground observatories in Australia, first the UK Schmidt telescope and later the Anglo-Australian telescope. But it is best known from the Hubble Space Telescope, which produced images in the 1990s with more details of the galaxy’s makeup. And just as the Webb, in July, revealed the presence of even more distant galaxies hiding from our view, its photographs of Cartwheel magnified the detailed formation of stars within the galaxy’s rings and the dozens of other star systems beyond.

The MIRI instrument on the Webb telescope was used to reveal the galaxy’s dusty regions and young stars. NASA, ESA, CSA, STScI, Webb ERO Production Tea

Cartwheel’s appearance comes from a collision of two galaxies that occurred hundreds of million of years ago. “We guess that the Cartwheel probably started out looking something like the Milky Way, and then this other galaxy moved through,” said Marcia Rieke, principal investigator of the near-infrared camera, or NIRCam, one of the Webb telescope’s scientific instruments. The smaller galaxy, though, rather than getting stuck in the large spiral it penetrated, continued on, moving away from the larger one. It is not visible in the image NASA published.

Galactic collisions are not uncommon in deep space, though it is rare for them to result in such a perfect shape that sparks human curiosity. Kirk Borne, who was the principal investigator for the Hubble observation of the Cartwheel but was not involved with the Webb, said that the galaxy’s strange shape, which formed by coincidence during the merger, has motivated astronomers to study it for decades.

Because a smaller galaxy crashed into a larger one — and straight through its middle — it was less disruptive to the shape of each galaxy, and both were relatively able to maintain their individuality. “What changed the Cartwheel’s shape was the influence of this other galaxy’s gravitational field that changed the orbits of stars in the original Cartwheel galaxy,” Dr. Rieke said.

Dr. Borne, who has studied other collisions of galaxies, described the smaller galaxy as a bullet that shot through the large one. After the observation of the cosmic object in the 1990s, the scientists noticed a trail of hydrogen gas left behind that was following the smaller galaxy, which Dr. Borne called the “smoking gun” indicating that it had kept moving after creating Cartwheel’s new formation.

Already 1.5 times the size of the Milky Way, Cartwheel is still expanding, and new stars are being formed both inside its outer ring and at its edge. However, there is no concrete answer on how large Cartwheel will become, when it will stop growing or what shape it will take when it does.

The images of Cartwheel were already in hand on July 12, though they were not available to the public until this week. They have been filtered to make them more visually accessible, highlighting vivid, blue-hued young stars and red-toned molecules from older stars and space dust floating between the rings. While colorful, Joseph DePasquale, a senior science visuals developer at the Space Telescope Science Institute, which manages the Webb and Hubble spacecraft, emphasized that the stars and dust are actually detected as infrared light instead of colors.

The new technology to detect that light in such detail is what distinguishes Webb’s images from those made by Hubble and the Anglo-Australian telescope. While Hubble had some capabilities to record light in the infrared spectrum, Webb’s are more advanced and create more vibrant pictures. The NIRCam, for instance, which was built by about 25 people working with Dr. Rieke over 11 years, distinguishes the stars’ infrared colors, which are invisible to the human eye, from one another.

In the Hubble telescope’s image of Cartwheel, the spokes were more obscured by gas clouds.ESA/Hubble & NASA

When Hubble captured Cartwheel in the 1990s, the galaxy’s “spokes” were obscured by gas clouds that scattered light, making it hard to see the thousands of stars forming within. Now, because the Webb can study mid-infrared and near-infrared light wavelengths, it is able to filter past the space dust. That helps to confirm some of the theories of Cartwheel’s makeup that were formed using Hubble’s technology and to uncover new information, such as the lack of star formation in some areas between the spokes of the wheel.

“I think the combination of the two telescopes, far from making one of them obsolete, this is actually just boosting the benefits and power of Hubble because now we can do these comparisons,” Dr. Borne said.

#Space | https://sciencespies.com/space/the-cartwheel-galaxy-is-the-webb-telescopes-latest-cosmic-snapshot/

DNA profiling solves Australian rabbit plague puzzle

Rabbits were first introduced to mainland Australia when five domestic animals were brought to Sydney on the First Fleet in 1788. At least 90 subsequent importations would be made before 1859 but none of these populations became invasive. But within 50 years, at a rate of 100 km per year, rabbits would spread across the entire continent, making this the fastest colonisation rate for an introduced mammal ever recorded. So what changed after 1859 and how did the invasion begin?

Historians and the Australian public have long assumed that the country’s ‘rabbit plague’ began at Barwon Park, the estate of Thomas Austin, near Geelong in Victoria. In a study published today in PNAS, an international team led by the University of Cambridge and CIBIO Institute in Portugal finally provides genetic proof for this version of events and settles a debate about whether the invasion arose from a single or several independent introductions.

On 6^th October 1859, Austin’s brother, William, sent a consignment of wild rabbits – caught on the family’s land in Baltonsborough in Somerset – together with some domestic rabbits, on the ship Lightning. On Christmas Day, 24 rabbits arrived in Melbourne and were dispatched to Barwon Park. Within three years, ‘Austin rabbits’ had multiplied into thousands, according to a local newspaper report and Austin himself.

The researchers studied historical records alongside new genetic data collected from 187 ‘European rabbits’ – mostly wild-caught across Australia, Tasmania, New Zealand, Britain and France between 1865 and 2018 – to establish where Australia’s invasive rabbits originated from; whether the invasion arose from a single or multiple introductions; how they spread across the country; and whether there was a genetic explanation for their success compared to that of other imported rabbit populations.

Recent studies disputed the single-origin hypothesis, instead arguing that invasive rabbits arose from several independent introductions. However, they did not sample ancestral European and domestic populations, which was crucial to disentangle the source of Australia’s rabbits. Lead author, Dr Joel Alves, who is currently a researcher at the University of Oxford and CIBIO Institute said:

“We managed to trace the ancestry of Australia’s invasive population right back to the South-West of England, where Austin’s family collected the rabbits in 1859.

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“Our findings show that despite the numerous introductions across Australia, it was a single batch of English rabbits that triggered this devastating biological invasion, the effects of which are still being felt today.”

The researchers found that as the rabbits moved further away from Barwon Park, genetic diversity declined and rare genetic variants which occur in rapidly growing populations became more frequent.

Despite the construction of rabbit-proof fences, the deliberate introduction of the myxoma virus and other measures, rabbits remain one of the major invasive species in Australia threatening native flora and fauna and costing the agricultural sector an estimated $200 million per year.

Previous studies have suggested that several factors contribute to biological invasions, including the number of individuals, the number of introductions, and environmental change. The new findings suggest that the genetic composition of those animals can be just, if not more, influential.

The researchers point out that if the trigger for the invasion had been environmental change, such as the development of large pastoral areas by human settlers, then multiple local rabbit populations would likely have expanded. The study’s genetic findings and the failure of pre-1859 rabbits to become invasive undermined this possibility.

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Instead, the team explored the possibility that the arrival of specific genetic traits acted as the trigger for the invasion, something which would help to explain the overwhelming genetic evidence for a single introduction.

The rabbits introduced to Australia before 1859 were often described as displaying tameness, fancy coat colours and floppy ears, traits associated with domestic breeds but normally absent in wild animals. Austin’s rabbits were described as wild-caught at the time, and the new study’s genetic findings prove that at least some of these animals were indeed wild.

Senior author Professor Francis Jiggins from Cambridge’s Department of Genetics said:

“There are numerous traits that could make feral domestic rabbits poorly adapted to survive in the wild but it is possible that they lacked the genetic variation required to adapt to Australia’s arid and semi-arid climate.

“To cope with this, Australia’s rabbits have evolved changes in body shape to help control their temperature. So it is possible that Thomas Austin’s wild rabbits, and their offspring, had a genetic advantage when it came to adapting to these conditions.”

In the 20^th century, Joan Palmer recalled that her grandfather William Austin had found it difficult to source the animals for Thomas “as wild rabbits were by no means common round Baltonsborough. It was only with great difficulty that he managed to get six; these were half-grown specimens taken from their nests and tamed. To make up the number he bought seven grey rabbits that the villagers had kept in hutches, either as pets or to eat”.

Alves and Jiggins found that the invasive rabbits descended from Austin’s imports contained a substantial element of domestic ancestry which they argue supports Joan Palmer’s claim that wild and domestic rabbits in the shipment bred before or during their 80-day journey, which would explain why more rabbits arrived than were sent.

Dr Alves said: “These findings matter because biological invasions are a major threat to global biodiversity and if you want to prevent them you need to understand what makes them succeed.”

“Environmental change may have made Australia vulnerable to invasion, but it was the genetic makeup of a small batch of wild rabbits that ignited one of the most iconic biological invasions of all time.”

“This serves as a reminder that the actions of just one person, or a few people, can have a devastating environmental impact.”

#Nature | https://sciencespies.com/nature/dna-profiling-solves-australian-rabbit-plague-puzzle/

JWST has taken even more beautiful images of Jupiter and its aurora

The James Webb Space Telescope has taken new images of Jupiter, showing off its bright hazes, tenuous rings and auroras with the hopes of understanding the entire system better

Space



22 August 2022

By Leah Crane

The orange glow at Jupiter’s poles are its aurora

NASA, ESA, CSA and Jupiter ERS Team. Image processing by Judy Schmidt

The James Webb Space Telescope (JWST) has released two stunning new images showcasing the complexities of Jupiter. While its previous images of the gas giant each used only one wavelength of light, these are composite images, showing Jupiter’s glowing auroras, shifting haze and two of its small moons.

Because JWST observes in infrared light, these images do not show Jupiter as it would look to the naked eye. Instead, different infrared wavelengths have been mapped to different colours to highlight particular features of the planet.

In the above image, the orange glow at Jupiter’s poles is its aurora. The green represents layers of tenuous high-altitude haze, while blue shows the main cloud layer. The white areas show the tops of storms, including the Great Red Spot.

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“We hadn’t really expected it to be this good, to be honest,” said Imke de Pater at University of California, Berkeley – who led this research along with Thierry Fouchet at the Paris Observatory – in a statement. “It’s really remarkable that we can see details on Jupiter together with its rings, tiny satellites, and even galaxies in one image.”

Jupiter and two of its small moons, Adrastea and Amalthea

NASA, ESA, CSA and Jupiter ERS Team. Image processing by Judy Schmidt

The wide-field image of Jupiter, above, shows not just Jupiter’s aurora – this time in blue – but also its tenuous rings. Lined up to the left of the planet are two of its small moons, Adrastea and Amalthea. The spots scattered throughout the image are mostly distant galaxies in the background.

De Pater and her colleagues hope that images like this will allow them to unravel the connections between Jupiter’s different layers and gain an understanding of how gas and heat move throughout the planet. They also aim to study the planet’s faint ring and how it evolves over time, as well as take pictures of some of its moons.

“This one image sums up the science of our Jupiter system program,” said Fouchet. The researchers are now analysing the data that was used to create these images, looking for hints as to Jupiter’s inner machinations.

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Sea urchin's secret to surviving marine heatwaves

Global ocean temperatures are increasing due to climate change, exposing ecosystems to extreme temperatures called marine heatwaves (MHWs), which can increase the temperature of marine waters by 5°C higher than normal in summer. MHWs can last several months and cause devastating effects on marine organisms.

Dr Bayden D. RUSSELL from The Swire Institute of Marine Science (SWIMS) and The School of Biological Sciences (SBS) at The University of Hong Kong (HKU), along with his research group, in collaboration with Dr Maria BYRNE, from the Sydney Institute of Marine Science, The University of Sydney (USyd), experimentally assessed whether adult sea urchins (Heliocidaris erythrogramma) that are exposed to marine heatwaves could pass beneficial protective mechanisms onto their offspring, thus ensuring the survival of the next generation. The findings indicated that adult sea urchins could pass on this heatwave resistance to the next generation. However, the study also identified that these carryover effects may not remain effective throughout the development and growth of juvenile urchins. The findings have been published in Global Change Biology.

Sea urchins are both economically and ecologically valuable. They maintain the structure and function of benthic marine ecosystems by eating algae that would otherwise take over these systems in the absence of urchins, making the ecosystem simpler and less biodiverse. This role is particularly important in ecosystems stressed by human activities like nutrient pollution or marine heatwaves, which benefit fast-growing algae that replace critical habitats like coral reefs or larger seaweed forests (e.g., kelp forests). Therefore, the continued survival of sea urchins under global heating is key to the continued function of many marine ecosystems.

This current research identified that the ability of urchins to survive extreme conditions through physiological adaptation, and pass on this resistance to the next generation fundamentally depends on their heat tolerance limits. When exposed to thermal stress, some urchin species have the ability to pass on protective mechanisms to their offspring as a means of defence should the offspring come up against the same type of stress as their parents. However, whether these 'carryover effects' remain effective throughout the development and growth of juvenile urchins and therefore allow them to survive till adulthood, can vary widely. Importantly, the research identified that different life stages can have very different abilities to cope with thermal stress; so, the responses seen in offspring may be different to that observed in their parents.

The research exposed adult sea urchins to different strengths of marine heatwaves and then spawned the adults under these conditions. The offspring were then reared across a range of temperatures, and their development was tracked to assess for carryover effects from the parents to their offspring. Surprisingly, heatwave-conditioned parents produced faster growing, larger and more heat tolerant offspring. If heatwaves continued, however, there was high mortality in offspring.

"If a MHW occurs at any time during the spawning period of the urchins, these carryover effects could lead to increased survival of the juveniles under what would normally be stressful temperatures. But, if the heatwave continues throughout the larval development, these short-term physiological responses may lead to higher mortality and ultimately reduce the survival of the next generation," said Dr Jay MINUTI, the lead author of the study and postdoctoral researcher at HKU SWIMS & SBS. Therefore, as these types of extreme events become more frequent and intense under climate change, the beneficial carryover effects of parental conditioning to MHWs will only protect the more sensitive juvenile stage and enhance survival if ocean conditions return promptly to normal temperatures.

"These findings are key for our understanding of what some marine ecosystems might look like under climate change," said Dr Bayden Russell. "Sea urchins play a key role in maintaining the function of ecosystems, so if the parents can help their offspring survive the extreme temperatures in marine heatwaves, then this may help overall ecosystem function. Unfortunately, it is clear that the only way to stop heatwaves from becoming worse is to reduce the effects of climate change by reducing carbon emissions. If we don't, then it is becoming clear that heatwaves will devastate marine ecosystems which are important for human society."

"The species of urchin that we used, Heliocidaris erythrogramma, is native to Australia and is ecologically important in near-shore areas," said Professor Maria Byrne at USyd, who uses Heliocidaris as a model species to investigate climate change impacts. "Its fast development is key to its success in nature, but also provides opportunities for trans-generational research to understand how marine species might adapt to climate change."

With many species of Heliocidaris urchins being ecologically and economically important worldwide (including Hong Kong), this research provides a first key insight into how the next generation could be protected by their parents from the negative effects of extreme temperatures caused by climate change.

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#Nature | https://sciencespies.com/nature/sea-urchins-secret-to-surviving-marine-heatwaves/

Quantum computer can simulate infinitely many chaotic particles

Using just a handful of quantum bits, researchers have used a quantum computer to simulate an infinite line of electron-like particles. The technique could be used to better understand the behaviour of molecules in materials

Physics



4 August 2022

By Karmela Padavic-Callaghan

Quantum bits made of charged ytterbium atoms kept in a glass and metal chamber

Quantinuum

A quantum computer made of charged atoms can use only a handful of quantum bits to simulate how an infinitely long and chaotic line of interacting particles behaves over time.

The behaviour of special materials, like superconductors, and molecules undergoing interesting chemical reactions is often too complex to simulate even on supercomputers. Researchers have long thought that quantum computers would be better at such tasks if they could build one large enough.

Eli Chertkov at the quantum computing company Quantinuum in Colorado and his colleagues have now devised a simulation algorithm that gets around this size constraint, enabling a quantum computer to simulate an infinitely long chain of interacting electron-like particles with very few quantum bits (qubits).

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The researchers used qubits made of charged ytterbium atoms. They programmed them to run the new algorithm, which simulates a chain of particles that all interact with each other. The team set up the interactions in such a way that past mathematical analyses suggested would make the particles behave chaotically – a mathematical concept that means very small changes in the initial arrangement have a big impact later on.

Usually, the number of particles a quantum computer can simulate depends on the number of qubits it can use. Here, the researchers used just three to 11 qubits.

Chertkov says that the Quantinuum quantum computer could do this because the algorithm directed it to keep “recycling” qubits during the calculation. When the computer needed more qubits, it would choose one it had already used, reset it and then reuse it, all without disturbing other qubits involved in the ongoing calculation.

The researchers already knew how a line of particles should behave over time from previous calculations and that is what they saw in their simulation, suggesting that it works.

Miles Stoudenmire at the Flatiron Institute in New York says that the next test for the new algorithm would be to simulate a system that conventional computers can’t handle, such as particles in 2D materials rather than just in a line. Understanding what electrons in those materials do over time, for instance, could help develop more efficient electronics devices.

Kaden Hazzard at Rice University in Texas says that the chaotic element makes the simulation more relevant to the real world. If you just picked a system inspired by nature at random, it would probably be chaotic, he says.

Reference: Nature Physics, DOI:10.1038/s41567-022-01689-7

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Sterile mice produce rat sperm

Researchers generated rat sperm cells inside sterile mice using a technique called blastocyst complementation. The advance appears August 4 in the journal Stem Cell Reports.

"Our study shows that we can use sterile animals as hosts for the generation of germ cells from other animal species," says senior author Ori Bar-Nur, a stem cell biologist at ETH Zurich. "Aside from a conceptual advancement, this notion can be utilized to produce endangered animal species gametes inside more prevalent animals. Other implications may involve an improved method to produce rat transgenic models for biomedical research."

Pluripotent stem cells (PSCs) provide a powerful tool for biomedical research, but the generation of gametes in the form of eggs or sperm cells from PSCs is a highly challenging endeavor. In prior studies, researchers used a technique called blastocyst complementation to generate rat organs in mice using PSCs and mutated mouse embryos that cannot produce specific organs. Building on this work, Bar-Nur and his collaborators wondered whether it would be possible to generate rat sperm inside mice that carry a genetic mutation that otherwise renders them sterile.

To test this idea, the researchers injected rat PSCs into mouse embryos to produce mouse-rat chimeras. An essential gene for sperm production was mutated in the mouse blastocysts. The rat stem cells developed together with the mouse cells, thereby generating a chimeric animal composed of genotypes from the two species. As a consequence of the genetic sterility-inducing mutation, an empty niche developed inside the testes, which enabled the rat cells to colonize them and exclusively generate rat sperm in mouse-rat chimeras. The sperm cells could fertilize rat egg cells, but the embryos did not develop normally or give rise to live offspring.

"We were surprised by the relative simplicity by which we could mix the two species to produce viable mouse-rat chimeras. These animals, by large, appeared healthy and developed normally, although they carried both mouse and rat cells in a chimeric animal," Bar-Nur says. "The second surprise was that indeed all the sperm cells inside the chimeras were of rat origin. As such, the mouse host environment, which was sterile due to a genetic mutation, was still able to support efficient sperm cell production from a different animal species."

Although the researchers were able to generate rat sperm cells that morphologically appeared indistinguishable from normal rat sperm cells, these cells were immotile and the fertilization rates of rat eggs was significantly lower in comparison to rat sperm cells produced in rats. Nonetheless, the work provides a proof-of-principle that one can generate sperm cells of one animal species in another by mixing the two species in an artificially generated organism called a chimera. Using sterile mice for genetically modified rat PSCs may speed up the production of transgenic rats to model human diseases in biomedical research.

Moving forward, the researchers will try to produce live animals from rat sperm cells that have been produced in mouse-rat chimeras. "We will need to improve the technique and demonstrate that rat sperm produced in mice can give rise to adult rats when fertilizing rat eggs," Bar-Nur says.

A more distant plan is to adapt this technique for the production of gametes from endangered rodent species to support animal species conservation efforts. "For example, to the extent we can procure stem cells from an endangered rodent, which at some point in time might become extinct, we may be able to employ the same method to produce its germ cells via chimera production with mice," Bar-Nur says. "However, it is important to note that several scientific hurdles will need to be overcome to adapt this technique to other animal species. In addition, one still needs to showcase the production of female reproductive cells (i.e., eggs) in female sterile mice, especially if we envision utilizing this technology for species conservation efforts."

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#Nature | https://sciencespies.com/nature/sterile-mice-produce-rat-sperm/