Scientists count the world's tree species (spoiler: it's a bunch)

Science

Scientists count the world’s tree species (spoiler: it’s a bunch)

Published

2 years ago

January 31, 2022

From the monkey puzzle tree of Peru to the Tasmanian blue gum of Australia, from the baobabs of Madagascar to the giant sequoias of California, the world is blessed with an abundance of tree species. How many? A new study has the answer.

Researchers on Monday unveiled the world’s largest forest data base, comprising more than 44 million individual trees at more than 100,000 sites in 90 countries – helping them to calculate that Earth boasts roughly 73,300 tree species.

That figure is about 14% higher than previous estimates. Of that total, about 9,200 are estimated to exist based on statistical modeling but have not yet been identified by science, with a large proportion of these growing in South America, the researchers said.

South America, home to the enormously biodiverse Amazon rainforest and farflung Andean forests, was found to harbor 43% of the planet’s tree species and the largest number of rare species, at about 8,200.

Trees and forests are much more than mere oxygen producers, said Roberto Cazzolla Gatti, a professor of biological diversity and conservation at the University of Bologna in Italy and lead author of the study published in the journal Proceedings of the National Academy of Sciences.

“Without trees and forests, we would not have clean water, safe mountain slopes, habitat for many animals, fungi and other plants, the most biodiverse terrestrial ecosystems, sinks for our excess of carbon dioxide, depurators of our polluted air, et cetera,” Gatti said.

“Indeed, our society often considers forests as just pieces of wood and trees as natural resources, ignoring their fundamental role for humankind in providing ecosystem services that go behind the mere economic – even if important – timber, paper and pulp production. From trees and forests humanity gets inspiration, relaxation, spirituality and essentially the meaning of life,” Gatti added.

South America was found to have about 27,000 known tree species and 4,000 yet to be identified. Eurasia has 14,000 known species and 2,000 unknown, followed by Africa (10,000 known/1,000 unknown), North America including Central America (9,000 known/2,000 unknown) and Oceania including Australia (7,000 known/2,000 unknown).

“By establishing a quantitative benchmark, our study can contribute to tree and forest conservation efforts,” said study co-author Peter Reich, a forest ecologist at the University of Michigan and University of Minnesota.

“This information is important because tree species are going extinct due to deforestation and climate change, and understanding the value of that diversity requires us to know what is there in the first place before we lose it,” Reich said. “Tree species diversity is key to maintaining healthy, productive forests, and important to the global economy and to nature.”

This study did not tally the total number of individual trees globally, but 2015 research led by one of the co-authors put that figure at about 3 trillion.

The new study pinpointed global tree diversity hot spots in the tropics and subtropics in South America, Central America, Africa, Asia and Oceania. It also determined that about a third of known species can be classified as rare.

The researchers used methods developed by statisticians and mathematicians to estimate the number of unknown species based on the abundance and presence of known species. Tropical and subtropical ecosystems in South America may nurture 40% of these yet-to-be-identified species, they said.

“This study reminds us how little we know about our own planet and its biosphere,” said study co-author Jingjing Liang, a professor of quantitative forest ecology at Purdue University in Indiana. “There is so much more we need to learn about the Earth so that we can better protect it and conserve natural resources for future generations.”

(Reporting by Will Dunham, Editing by Rosalba O’Brien)

Science

WATCH — This tiny fish is louder than an elephant – CBC.ca

Published

5 mins ago

April 18, 2024

Harry Miller

These fish are also transparent

Danionella cerebrum may be small fry, but the noises they make are anything but.

Think louder than an elephant.

These tiny fish, which measure up to 12 millimetres long, were the subject of a study published in the journal Proceedings of the National Academy of Sciences on Feb. 24.

Researchers from the Charité Universitätsmedizin, a university hospital in Berlin, and the Senckenberg Society Natural History Collections in Dresden, both in Germany, collaborated on the study.

Their research uncovered the apparatus that allows male Danionella cerebrum fish to make loud, pulsing noises, and theorizes why this behaviour evolved in the first place.

Researchers recorded the fish in a tank. This video is slowed down 10 times to see how they moved. (Video credit: Verity Cook/Charité)

How did the study work?

The researchers put four Danionella cerebrum in a tank.They captured both audio and visual recordings, and performed scans, dissections and gene analyses.

Because these fish have transparent skin, cameras could see and record what happens inside their bodies to make such loud noises.

A study model shows how the Danionella cerebrum creates its sounds. A drumming muscle (green) contracts, pulling the rib (red), which fits into a groove in the cartilage (light blue) and builds tension. The tension is released and the cartilage snaps back into place, striking the swim bladder (purple). (Video credit: Verity Cook/Charité)

First, a special drumming muscle contracts.

It pulls on a rib that moves something called the drumming cartilage out of place — a bit like stretching a rubber band.

Then, suddenly, the drumming cartilage snaps back into position so fast it strikes the swim bladder (a special organ fish have to help them swim).

This impact produces the loud pulse we hear.

Click play on the video at the top of the page to hear the Danionella cerebrum for yourself!

Why so loud?

The noises made by male Danionella cerebrum can be as loud as 147 decibels at a distance of one body length away.

That’s about as loud as a jet engine would sound taking off 100 metres away from you.

The researchers believe these pulses are a way for the fish to communicate.

Danionella cerebrum’s native habitat are shallow, murky waters in Myanmar.

The scientists say this lack of visibility could mean sound communication evolved to help the fish locate mates.

The Danionella cerebrum is about as long as the diameter of a typical AA battery. (Image credit: Senckenberg, with graphic design by Philip Street/CBC)

A unique opportunity

The study broadens our understanding of how animals make noise and why these behaviours might have evolved.

Now, the scientists hope to study the four other species in the Danionella family, to compare how they produce sounds.

Click play to hear the itsy-bitsy fish for yourself!

Check out these other animal news videos:

Have more questions? Want to tell us how we’re doing? Use the “send us feedback” link below. ⬇️⬇️⬇️

TOP IMAGE CREDIT: Senckenberg, with graphic design by Philip Street/CBC

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Local astronomer urges the public to look up – Windsor News Today – windsornewstoday.ca

Published

10 hours ago

April 18, 2024

Harry Miller

If last week’s solar eclipse piqued your interest in astronomy, the Royal Astronomical Society of Canada’s Windsor Chapter plans to show off some of the more dramatic photos and videos members took of the event.

They were stationed along the path of totality along the northern shore of Lake Erie and in the U.S.

“People did take some nice photos with their cellphones, but we have members who took photos and videos with their telescopes,” said member Tom Sobocan. “You’ll see some pretty impressive shots.”

About 100 members are in the local chapter, which meets every third Tuesday of every month.

Thursday’s meeting is at the Ojibway Nature Centre on Matchette Road. It starts at 7:30, and it’s open to the public. Seating is limited, so Sobocan recommends arriving early.

Astronomers are looking ahead to new wonders in the heavens. Right now, the Pons-Brooks Comet, another once-in-a-lifetime opportunity, is approaching Jupiter in the constellation of Aries.

“If you’re in a dark-sky location, you can see it with the naked eye, and from inside the city, you can see it with binoculars,” said Sobocan. “It may get a little bit brighter going towards the fall, but our members have already photographed it with their telescopes.”

It’s a periodic comet which appears in the night sky once every 71 years.

Sobocan said once-in-a-lifetime events, like last week’s eclipse, inspired many of its existing members, but he hopes some new ones will join the group.

“I hope it inspires them to look up at the sky a little bit more often and realize that everything’s in motion in the sky,” he said. “It’s not stationary.”

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Giant, 82-foot lizard fish discovered on UK beach could be largest marine reptile ever found – Livescience.com

Published

11 hours ago

April 17, 2024

Harry Miller

Scientists have unearthed the remains of a gigantic, 200 million-year-old sea monster that may be the largest marine reptile ever discovered.

The newfound creature is a member of a group called ichthyosaurs, which were among the dominant sea predators during the Mesozoic era (251.9 million to 66 million years ago). The newly described species lived during the end of the Triassic period (251.9 million to 201.4 million years ago).

Ichthyosaurs had already attained massive sizes by the early portion of the Mesozoic, but it was not until the late Triassic that the largest species emerged.

While the Mesozoic is known as the age of the dinosaurs, ichthyosaurs were not themselves dinosaurs. Instead, they evolved from another group of reptiles. Their evolutionary path closely mirrors that of whales, which evolved from terrestrial mammals that later returned to the sea. And like whales, they breathed air and gave birth to live young.

The newly discovered ichthyosaur species was unearthed in pieces between 2020 and 2022 at Blue Anchor, Somerset in the United Kingdom. The first chunk of the fossil was noticed atop a rock on the beach, indicating that a passerby had found it and set it there for others to examine, the researchers explained in the paper. The researchers published their findings April 17 in the journal PLOS One.

The reptile’s remains are made up of a series of 12 fragments from a surangular bone, which is found in the upper portion of the lower jaw. The researchers estimate the bone was 6.5 feet (2 meters) long and that the living animal was about 82 feet (25 m) long.

The researchers named the sea monster Ichthyotitan severnensis, meaning giant lizard fish of the Severn, after the Severn Estuary where it was found. The team believes it is not only a new species but an entirely new genus of ichthyosaur. More than 100 species are already known.

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A giant pair of swimming Ichthyotitan severnensis. (Image credit: Gabriel Ugueto, CC-BY 4.0)

A number of rib fragments and a coprolite, or fossilized feces, were found in the area as well, but they were not definitively attributed to the same animal.

The sediments in which these specimens were found contained rocks that indicated earthquakes and tsunamis occurred during that time, which suggests that this species lived during a time of intense volcanic activity that may have led to a massive extinction event at the end of the Triassic according to the researchers.

A similar specimen was discovered in Lilstock, Somerset in 2016 and described in 2018. Both were found in what is known at the Westbury Mudstone Formation, within 6 miles (10 kilometers) of each other. This ichthyosaur was estimated to have been as much as 85 feet (26 m) long, although the authors of the latest study believe it was slightly smaller.

The previous contender for the largest marine reptile was another ichthyosaur, Shonisaurus sikanniensis, which was up to 69 feet (21 m) long. S. sikanniensis appeared 13 million years earlier than I. severnensis and was found in British Columbia, making it unlikely that the new discovery represents another specimen of the previously known species.

A similarly massive ichthyosaur called Himalayasaurus tibetensis, which may have reached lengths of 49 feet (15 m), was discovered in Tibet and described in 1972. It dates to the same period, meaning that it probably is not the same species as the new discovery either.

I. severnensis was likely among the last of the giant ichthyosaurs, the researchers claim. Ichthyosaurs persisted into the Cenomanian Age (100.5 million to 93.9 million years ago) of the late Cretaceous period (100.5 million to 66 million years ago). They were eventually supplanted by plesiosaurs — long-necked marine reptiles that went extinct at the end of the Cretaceous, alongside all non-avian dinosaurs.

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