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

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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)

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My Thesis in 400 Words: Anne Boucher | Institute for Research on Exoplanets – News | Institute for Research on Exoplanets

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Anne Boucher, an iREx student at the Université de Montréal, submitted her doctoral thesis at the end of 2021. She summarises the research project she carried out as part of her Ph.D here.

During my Ph.D, I became interested in the atmosphere of gas giant exoplanets that orbit very close to their star. Thanks to a technique called transmission spectroscopy, I studied the chemical composition of their atmosphere, which gives a lot of information on their formation and evolution mechanisms. The detailed study of these exoplanets, which we sometimes call hot Jupiters or hot sub-Saturns, provides a better understanding of the physical, chemical, and dynamical processes that govern the atmosphere of these celestial objects.

I mainly used data from the SPIRou instrument, a high-resolution spectropolarimeter that operates in the near infrared and is installed at the Canada-France-Hawaii Telescope. We first observed HD 189733 b, one of the most studied exoplanets, to build the analysis codes. By exploiting transit spectroscopy, we were able to confirm the presence of water and determine its abundance. The results obtained, consistent with previous studies, indicate that the atmosphere of HD 189733 b is relatively clear (free of clouds) and that the planet likely formed far from its star, where it is cold enough to find water in the form of ice. A strong blueshift of water absorption was observed, which could be a consequence of the presence of strong winds in the atmosphere.

Artistic representation of the exoplanet HD 189733 b, credit :  NASA, ESA, and G. Bacon (STScI)

Next, we studied WASP-127 b, a less massive exoplanet, but much larger than Saturn. A recent study of data from the Hubble Space Telescope (HST) and the Spitzer Space Telescope could not differentiate between two atmospheric scenarios: a low carbon-to-oxygen (C/O) ratio with little carbon monoxide (CO), or a high ratio with a lot of CO. As this ratio helps to determine how a planet was formed, we decided to use SPIRou, which makes it possible to observe a band of CO not observable with HST and Spitzer. We were able to determine that there was very little CO and a very low C/O, which has rarely been observed, but which is supported by some more realistic training scenarios that vary over time. The SPIRou data also confirmed the presence of water and suggests that, if confirmed, there could even be hydroxyl (OH): an unexpected detection since the exoplanet is so cold.

This work has allowed to develop the expertise of the Université de Montréal in high resolution near-infrared transit spectroscopy, in particular with SPIRou, allowing to explore the atmospheric conditions of hot Jupiters and sub-Saturns. This first joint analysis made on high and low resolution transmission data allowed to obtain better constraints on the atmospheric parameters. This method is proving to be a very powerful tool for the study of atmospheres and will be even more so with the revolutionary capabilities of JWST.

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Anne worked on her Ph.D. at the Université de Montréal between 2016 and 2022, under the supervision of David Lafrenière. Her thesis will soon be available.

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Nicolas Cowan, Finalist for the 2021 Relève scientifique Prize – News | Institute for Research on Exoplanets

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Nicholas Cowan. Credit: McGill University.

Nicolas Cowan, Professor at McGill University and a member of both iREx and the McGill Space Institute, is one of the finalists for the Relève Scientifique du Québec 2021 Prize, an award which aims to highlight the commitment and excellence in research of a person 40 years of age or younger.

Nick has been a Professor in the Departments of Physics and Earth and Planetary Sciences at McGill University since 2015. He specialises in astrobiology and mainly studies the surface and atmosphere of exoplanets. He is particularly interested in the climate of these planets found outside of our Solar System.

The researcher mainly uses space- and ground-based telescopes to collect and analyse data which he uses to study the characteristics of various exoplanets. More specifically, the data seeks to measure the reflection of clouds, detect the presence of greenhouse gases via the infrared signature of the atmosphere, and heat transport, i.e. the winds. These data are used to create maps of the surface and the temperature of exoplanets, a method commonly referred to as exo-cartography. The study of the exoplanets’ climate also allows us to learn a lot about that of our planet, Earth.

Nick’s commitment to the research community is illustrated in particular by his participation in numerous NASA and Canadian Space Agency committees to promote the study of planetary climates and to contribute to the planning of future space missions to study exoplanets.

In addition to his work as a researcher, Nick is also involved in the Astronomy in Indigenous Communities program, which aims to attract Indigenous youth to pursue a career in STEM.

It is with pride that the iREx congratulates Nicolas Cowan for this distinction.

About the Relève scientifique du Québec Prize

The Relève scientifique du Québec prize is awarded to a person aged 40 or under who has distinguished themselves by the excellence of their research and who demonstrates the ability to establish and maintain constructive and lasting links with the research community. All disciplines are recognised for this award. Each year one recipient and two finalists are selected.

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NASA: Contact lost with spacecraft on way to test moon orbit – Phys.org

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Rebecca Rogers, systems engineer, left, takes dimension measurements of the CAPSTONE spacecraft in April 2022, at Tyvak Nano-Satellite Systems, Inc., in Irvine, Calif. NASA said Tuesday, July 5, that it has lost contact with a $32.7 million spacecraft headed to moon to test out a lopsided lunar orbit, but agency engineers are hopeful they can fix the problem. Credit: Dominic Hart/NASA via AP

NASA said Tuesday it has lost contact with a $32.7 million spacecraft headed to the moon to test out a lopsided lunar orbit, but agency engineers are hopeful they can fix the problem.

After one successful communication and a second partial one on Monday, the said it could no longer communicate with the spacecraft called Capstone. Engineers are trying to find the cause of the communications drop-off and are optimistic they can fix it, NASA spokesperson Sarah Frazier said Tuesday.

The spacecraft, which launched from New Zealand on June 28, had spent nearly a week in Earth orbit and had been successfully kick-started on its way to the moon, when contact was lost, Frazier said.

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The 55-pound satellite is the size of a microwave oven and will be the first spacecraft to try out this oval orbit, which is where NASA wants to stage its Gateway outpost. Gateway would serve as a staging point for astronauts before they descend to the .

The orbit balances the gravities of Earth and the moon and so requires little maneuvering and therefore fuel and allows the satellite—or a —to stay in constant contact with Earth.


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NASA satellite breaks from orbit around Earth, heads to moon


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