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The power of earthworm poop and how it could influence climate change – CBC.ca

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There is a confounding mystery wrapped up in the tiny turds of two different types of earthworms, and the secrets locked inside are influencing climate change around the world.

Scientists say some earthworm species are potentially speeding up climate change by feeding on leaves, then pooping out a mix that’s fodder to tiny microbes and fungi that spew carbon into the atmosphere. By contrast, other worms are helping lock carbon in soil.

Canada is ground zero for this paradox. Earthworm populations are growing as warmer temperatures allow the invertebrates to move farther north than ever before.

And no one knows exactly how much carbon they are helping release into the atmosphere.

“Some of the early work has shown that they could have as much of an impact as, let’s say, wildfire,” said Sylvie Quideau, a professor of soil biogeochemistry at the University of Alberta.

It’s possible, she said, worms in Canada could release millions of tonnes of carbon into the atmosphere in a year, but that estimate is still subject to a lot of uncertainties, including the rate of earthworm invasion across the country.

Sylvie Quideau, a professor of soil biogeochemistry at the University of Alberta, says early work on earthworms show ‘they could have as much of an impact as, let’s say, wildfire.’ (Submitted by Sylvie Quideau)

The most common earthworms that live in leaf litter, on forest floors or in the top layers of soil are called Dendrobaena octaedra. They eat plant debris, and their poop, also known as casts, is more easily broken down by microbes and fungi that then release carbon dioxide.

“Microbes find earthworm poop very attractive,” said Quideau.

The more earthworms there are, the more plant debris is broken down at a faster rate and the more carbon gets released into the atmosphere.

This kind of carbon being released from Canada’s boreal forests is new, according to Quideau, since earthworms are not native to the country. They were wiped out during the last ice age.

The earthworms here now, save for some found in British Columbia, are invasive species transported into forests when Europeans arrived or brought them in from the United States as fishing bait.

“Earthworms can both be allies and enemies,” said Joann Whalen, a professor in the department of natural resource sciences at Montreal’s McGill University who has studied earthworms for 20 years. 

In agriculture, earthworms are beneficial, said Whalen: They help make soil more fertile, and allow water and roots to more easily enter the ground. 

In spring, it is common to see spherical lumps of earth on the soil surface. These earthworm casts are a mixture of soil and organic residues that all earthworm species poop out or egest onto the soil surface. The white object is a toonie, to give an idea of the cast size. (Submitted by Joann Whalen)

In the boreal forest, worms can do more harm than good. 

Some eat the leaf litter covering the forest floor, and many plant seeds need that thick covering to grow in. Without it, the seeds can’t take root, said Whalen, which means earthworms can reduce plant diversity in the forest.

But earthworms aren’t all bad. There are some burrowing species that actually trap carbon in the soil, because their poop binds it more tightly and makes it harder for microbes to break down.

Often sold as fishing bait, Lumbricus terrestris is a common deep-burrowing earthworm found in Canada. It can be identified by the small mounds of earth it leaves on lawns or in forests.

How much carbon is being trapped by these worms and whether it’s enough to offset the carbon other worms are helping release isn’t clear. Finding the answer to that question is part of Quideau’s research.

“What keeps me up at night is wondering if I can quantify their effect on climate change,” she said.

‘Earthworms can both be allies and enemies,’ says Joann Whalen, a professor in the department of natural resource sciences at Montreal’s McGill University. (Submitted by Joann Whalen)

Whalen isn’t losing any sleep over worms. She said the carbon dioxide coming from decomposing plant material is a natural process, and worms help it.

“I’d be more concerned about what people are doing in terms of utilizing fossil carbon that had been buried for millennia and is now being released into the atmosphere.”

Still, in Canada, the earthworm invasion continues.

Erin Cameron, an assistant professor in the department of environmental science at Saint Mary’s University in Halifax, has been monitoring the invasion’s progress since 2006. 

In northern Alberta, she’s been studying how fast earthworms are spreading, and has discovered they are moving north at a rate of 17 metres a year. The earthworm population appears to have grown as well.

Dendrobaena octaedra is one of the most common earthworms that live in the leaf litter on the forest floor or in the top layers of soil. (Submitted by Erin Cameron)

The most abundant kind of earthworm she finds live in leaf litter or in the top layers of soil, the ones that help release carbon into the air.

“Earthworms may benefit from warmer temperatures in Canada’s North, for example, because that may currently be restricting the distributions of some species,” said Cameron.

So as climate change continues to warm the country, earthworms could continue to become more abundant and possibly drive more climate change.

Erin Cameron, an assistant professor in the department of environmental science at Saint Mary’s University, has been monitoring the earthworm invasion’s progress since 2006. (Submitted by Erin Cameron)

Quideau doesn’t think there’s anything that can be done to stop the worm march through Canada.

“What’s important is that we can understand, quantify their effect better so that we can project better in the future what their influence will be. There might be ways then to manage a forest.”

She and other researchers hope to do just that in the next few years. They want to crack the secret of earthworm poop, and determine how much carbon earthworms release and store in the earth.

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NASA’s Hubble Space Telescope captured two festive-looking nebulas – Tech Explorist

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The image shows NGC 248, about 60 light-years long and 20 light-years wide. They are two nebulas, situated to appear as one. The nebulas, together, are called NGC 248.

Initially discovered in 1834 by the astronomer Sir John Herschel, NGC 248 resides in the Small Magellanic Cloud, located approximately 200,000 light-years away in the southern constellation Tucana.

Small Magellanic Cloud is a dwarf galaxy that is a satellite of our Milky Way galaxy. The image is part of a study called Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE).

The dwarf satellite galaxy contains several brilliant hydrogen nebulas, including NGC 248. Intense radiation from the brilliant central stars is heating hydrogen in each nebula, causing them to glow red.

The study’s principal investigator, Dr. Karin Sandstrom of the University of California, San Diego, said“The Small Magellanic Cloud has between a fifth and a tenth of the amount of heavy elements that the Milky Way does. Because it is so close, astronomers can study its dust in great detail and learn about what dust was like earlier in the history of the universe.”

“It is important for understanding the history of our galaxy, too. Most of the star formation happened earlier in the universe, at a time when there was a much lower percentage of heavy elements than there is now. Dust is a critical part of how a galaxy works, how it forms stars.”

The image is part of a study called Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE). The data used in this image were taken with Hubble’s Advanced Camera for Surveys in September 2015.

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When To See An ‘Earth-Grazer’ This Weekend: Don’t Write-Off The Perseid Meteor Shower, Says Expert – Forbes

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If you’ve ever laid down a blanket or set up a lawn chair to watch a meteor shower there’s a good chance it was to watch the Perseids.

Due to peak at 01:00 UT on Saturday, August 13, 2022, normal advice would be to be outside at that time (in Europe) or just as soon as its gets dark on Friday, August 12 (North America).

As I’ve already reported, this year the Perseids coincides with a full Moon, so all but the brightest meteors and “fireballs” (larger, brighter meteors) will be visible. So from the 50-75-or-so “shooting stars” you might normally see during the peak of the Perseids only a few—albeit bright—meteors will be visible.

It’s almost not worth the bother, I said, advising you to go watch this instead next weekend.

However, there is another opinion. In an article published on the American Meteor Society’s website, fireball coordinator Robert Lunsford says that despite the bright full Moon visible meteor rates during the peak of the Perseid meteor shower will be better than 95% of all other nights this year.

When to see the Perseid meteor shower

“Most of the Perseid meteors are faint and bright moonlight will make it difficult to view,” he writes. “Despite the glare of moonlight, the Perseids produce many bright meteors that can still be easily seen despite the bright moonlight.”

He also advises two great times to watch for shooting stars—just after sunset on Friday, August 12 and just before dawn on Saturday, August 13.

Perseids: ‘Earth-grazers’ just after sunset

You’ll need patience, but to see an “Earth-grazer” is unforgettable.

Just after sunset is actually thee worst time in terms of numbers of shooting stars you might see, but the few that do come your way this time of night are special.” The reason is that they just skim the upper regions of the atmosphere and will last much longer than Perseids seen during the morning hours,” writes Lunsford. “Most of these “earth-grazing” Perseids will be seen low in the east or west, traveling north to south.”

Perseids: ‘shooting stars’ before dawn

The activity from the Perseid meteor shower will peak where you are as the radiant—the constellation of Perseus—rises higher into the night sky. “Theoretically, the best time to watch the Perseids is just before the break of dawn when the radiant lies highest in a dark sky,” writes Lunsford. That’s about 04:00 local time, though he also reveals that experienced observers often say the hour between 03:00 and 04:00 is usually the best.

Perseids: ‘shooting stars’ in a moonless sky

If you want to look for Perseids in a dark, moonless sky then you’re mostly out of luck this year. By the time the full Moon is rising long after midnight the meteor rates will have vastly reduced, though it may be worth shooting star-gazing after August 19, 2022.

When is the Perseid meteor shower in 2023?

The Perseid meteor shower will next year peak—in thankfully moonless skies—at around 07:00 UT on August 13, 2023 (so 03:00 EST and midnight PST), which will be ideal for North America.

Wishing you clear skies and wide eyes.

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Meet Qikiqtania, a fossil fish who stayed in the water while others ventured onto land – Big Think

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Approximately 365 million years ago, one group of fishes left the water to live on land. These animals were early tetrapods, a lineage that would radiate to include many thousands of species including amphibians, birds, lizards and mammals. Human beings are descendants of those early tetrapods, and we share the legacy of their water-to-land transition.

But what if, instead of venturing onto the shores, they had turned back? What if these animals, just at the cusp of leaving the water, had receded to live again in more open waters?

A new fossil suggests that one fish, in fact, did just that. In contrast to other closely related animals, which were using their fins to prop their bodies up on the bottom of the water and perhaps occasionally venturing out onto land, this newly discovered creature had fins that were built for swimming.

Tom Stewart holds the Qikiqtania fossil. (Stephanie Sang / CC BY-ND)

In March 2020, I was at The University of Chicago and a member of biologist Neil Shubin’s lab. I was working with Justin Lemberg, another researcher in our group, to process a fossil that was collected back in 2004 during an expedition to the Canadian Arctic.

From the surface of the rock it was embedded in, we could see fragments of the jaws, about 2 inches long (5 cm) and with pointed teeth. There were also patches of white scales with bumpy texture. The anatomy gave us subtle hints that the fossil was an early tetrapod. But we wanted to see inside the rock.

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So we used a technology called CT scanning, which shoots X-rays through the specimen, to look for anything that might be hidden within, out of view. On March 13, we scanned an unassuming piece of rock that had a few scales on top and discovered it contained a complete fin buried inside. Our jaws dropped. A few days later, the lab and campus shut down, and COVID-19 sent us into lockdown.

The fin revealed

A fin like this is extremely precious. It can give scientists clues into how early tetrapods were evolving and how they were living hundreds of millions of years ago. For example, based on the shape of certain bones in the skeleton, we can make predictions about whether an animal was swimming or walking.

Although that first scan of the fin was promising, we needed to see the skeleton in high resolution. As soon as we were allowed back on campus, a professor in the university’s department of the geophysical sciences helped us to trim down the block using a rock saw. This made the block more fin, less rock, allowing for a better scan and a closer view of the fin.

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When the dust had cleared and we’d finished analyzing data on the jaws, scales and fin, we realized that this animal was a new species. Not only that, it turns out that this is one of the closest known relatives to limbed vertebrates – those creatures with fingers and toes.

We named it Qikiqtania wakei. Its genus name, pronounced “kick-kiq-tani-ahh,” refers to the Inuktitut words Qikiqtaaluk or Qikiqtani, the traditional name for the region where the fossil was found. When this fish was alive, many hundreds of millions of years ago, this was a warm environment with rivers and streams. Its species name honors the late David Wake, a scientist and mentor who inspired so many of us in the field of evolutionary and developmental biology.

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Skeletons tell how an animal lived

Qikiqtania reveals a lot about a critical period in our lineage’s history. Its scales tell researchers unambiguously that it was living underwater. They show sensory canals that would have allowed the animal to detect the flow of water around its body. Its jaws tell us that it was foraging as a predator, biting and holding onto prey with a series of fangs and drawing food into its mouth by suction.

But it is Qikiqtania’s pectoral fin that is most surprising. It has a humerus bone, just as our upper arm does. But Qikiqtania’s has a very peculiar shape.

Early tetrapods, like Tiktaalik, have humeri that possess a prominent ridge on the underside and a characteristic set of bumps, where muscles attach. These bony bumps tell us that early tetrapods were living on the bottom of lakes and streams, using their fins or arms to prop themselves up, first on the ground underwater and later on land.

Qikiqtania’s humerus is different. It lacks those trademark ridges and processes. Instead, its humerus is thin and boomerang-shaped, and the rest of the fin is large and paddle-like. This fin was built for swimming.

Whereas other early tetrapods were playing at the water’s edge, learning what land had to offer, Qikiqtania was doing something different. Its humerus is truly unlike any others known. My colleagues and I think it shows that Qikiqtania had turned back from the water’s edge and evolved to live, once again, off the ground and in open water.

Evolution isn’t a march in one direction

Evolution isn’t a simple, linear process. Although it might seem like early tetrapods were trending inevitably toward life on land, Qikiqtania shows exactly the limitations of such a directional perspective. Evolution didn’t build a ladder towards humans. It’s a complex set of processes that together grow the tangled tree of life. New species form and they diversify. Branches can head off in any number of directions.

Neil Shubin, who found the fossil, pointing across the valley to the site where Qikiqtania was discovered on Ellesmere Island. (Neil Shubin / CC BY-ND)

This fossil is special for so many reasons. It’s not just miraculous that this fish was preserved in rock for hundreds of millions of years before being discovered by scientists in the Arctic, on Ellesmere Island. It’s not just that it’s remarkably complete, with its full anatomy revealed by serendipity at the cusp of a global pandemic. It also provides, for the first time, a glimpse of the broader diversity and range of lifestyles of fishes at the water-to-land transition. It helps researchers see more than a ladder and understand that fascinating, tangled tree.

Discoveries depend on community

Qikiqtania was found on Inuit land, and it belongs to that community. My colleagues and I were only able to conduct this research because of the generosity and support of individuals in the hamlets of Resolute Bay and Grise Fiord, the Iviq Hunters and Trappers of Grise Fiord, and the Department of Heritage and Culture, Nunavut. To them, on behalf of our entire research team, “nakurmiik.” Thank you. Paleontological expeditions onto their land have truly changed how we understand the history of life on Earth.

COVID-19 kept many paleontologists from traveling and visiting field sites across the world these last few years. We’re eager to return, to visit with old friends and to search again. Who knows what other animals lie hidden, waiting to be discovered inside blocks of unassuming stone.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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