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.
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
