Science word of the day: Pando

Pronunciation: PAN'-doh

What it means: In Latin, "Pando" means "I spread." And boy, does it. Pando is a clonal stand of aspen trees in Utah that weighs about 13 million pounds (6 million kilograms), making it the world's heaviest living organism ever found. Its 40,000 trees cover 106 acres (43 hectares) in Fishlake National Forest, and they're all connected by a single, sprawling root system. Some DNA analysis suggests that this many-fingered megatree is tens of thousands of years old.

How to use it in a sentence: When you walk through Pando, what seems like a normal stroll through an aspen grove is actually a trip through a single, ancient living being.

Can you crack our science word of the day puzzle, Chain Word?

For decades, cities have been designed around "gray infrastructure." Roads move people. Bridges connect communities. Water systems protect public health. These systems are governed by engineering standards because society recognizes that safety cannot depend on good intentions alone.

Urban nature deserves the same recognition.

In June, a heat wave gripped Europe, breaking temperature records across the continent. In France, officials reported over 2,000 excess deaths. In the U.K., hospitals declared critical incidents and machinery and IT systems failed. In the U.S., a heat dome over the Midwest and East Coast disrupted Fourth of July celebrations, with at least 25 heat-related deaths over Independence Day weekend.

Cities are being tested by a warming climate. Yet one of our most effective forms of climate infrastructure is being lost — not because it does not work but because we still do not treat it as infrastructure.

My view is simple: Urban nature ‪—‬ including street trees, parks, wetlands and other urban green spaces ‪—‬ should be categorized and managed as essential infrastructure, with minimum standards for its protection, quality and long-term maintenance. Just as we regulate roads, bridges and drinking water, we need standards that ensure all urban residents benefit from healthy and thriving urban nature. Without such standards, cities will become hotter, less resilient and increasingly unequal as climate change accelerates.

Scientific research shows that urban trees and green spaces cool cities during heat waves, reduce flooding by absorbing stormwater, improve air quality, store carbon, support biodiversity, and improve both physical and mental health. During extreme heat, neighborhoods with mature tree canopies can be several degrees cooler than nearby streets dominated by concrete and asphalt. Those few degrees can mean the difference between manageable discomfort and dangerous heat exposure, particularly for older adults, children and people with existing health conditions.

But while the science is strong, our governance is not.

Cities enthusiastically announce ambitious tree-planting campaigns, biodiversity strategies and new greening targets. These initiatives are valuable, but they often focus on what is easy to count rather than what truly matters. Planting a tree is not the same as growing a healthy urban forest. Creating a park does not guarantee biodiversity. A green roof delivers little value if it fails during drought.

The real measure of success is whether urban nature continues providing benefits decades after trees are planted and established.

This is where cities are still falling short.

Unlike buildings or transport systems, urban nature rarely operates under consistent minimum standards. Many cities have no requirements for minimum tree canopy cover, adequate rooting space, soil quality, biodiversity targets, long-term maintenance or even whether newly planted trees survive. As a result, access to nature depends heavily on where people live. Wealthier neighborhoods often enjoy mature tree canopy and high-quality parks, while disadvantaged communities experience hotter streets, fewer green spaces and greater exposure to climate risks.

That is not simply an environmental issue. It is a public health issue, a climate adaptation issue, and an issue of social equity.

The solution is not simply to plant more trees. It is to establish urban nature standards that recognize nature as essential infrastructure.

These standards would not prescribe the same solution for every city. Instead, they would establish minimum expectations based on scientific evidence. They could include targets for accessible green space, minimum tree canopy cover, sufficient soil volume for healthy tree growth, biodiversity outcomes, long-term maintenance funding and routine monitoring to ensure that urban nature continues delivering benefits to communities.

Importantly, these standards should focus on outcomes rather than simple planting targets. Counting how many trees are planted tells us little about whether cities are becoming more resilient. Measuring survival, canopy development, ecosystem health and equitable access provides a much better picture of whether investments in urban nature are actually returning dividends.

Some critics argue that cities cannot afford stronger standards for urban nature. Municipal budgets are already stretched by housing, transport and aging infrastructure. But this argument overlooks a fundamental reality: We already spend enormous sums responding to the consequences of extreme heat, flooding, poor air quality and declining public health. Healthy urban ecosystems help reduce these costs while delivering multiple benefits simultaneously.

As climate change accelerates, the distinction between gray and green infrastructure becomes increasingly blurred. Trees cool buildings and reduce energy demand. Wetlands decrease flood damage. Parks improve public health and strengthen communities. These are not optional amenities. They are functioning components of urban infrastructure that deserve the same level of planning, investment and accountability as any engineered system.

Building codes transformed the safety of our cities because they established minimum standards that every development had to meet. Climate resilience now demands a similar transformation for urban nature.

The next generation of resilient cities will not be defined simply by how many trees they plant but by the standards they adopt to protect, restore and sustain the living infrastructure urban life depends on.

The real question is not whether cities can afford to invest in urban nature; it is whether they can afford not to.

Opinion on Live Science gives you insight on the most important issues in science that affect you and the world around you today, written by experts and leading scientists in their field.

Trees in China that were planted as part of huge reforestation projects appear to grow faster than those in natural forests, a new study finds. This is possibly because the reforestation trees are responding more strongly to the rising atmospheric carbon dioxide, scientists say.

China is quickly turning green. The country has planted 66 billion trees since 1978, with plans for 34 billion more by the middle of this century, as part of its "Great Green Wall" to slow the spread of the Gobi and Taklamakan deserts.

These new forests absorb large amounts of CO₂, but it is unclear exactly how they differ from natural ones, study first author Yuhang Luo, a landscape ecologist at Peking University in Shenzhen, China, told Live Science.

Luo and his colleagues set out to study how differences between natural and planted forests, including species diversity, tree density and age, might affect how the forests respond to rising CO₂ and climate change.

"Planted forests are widely used in climate mitigation strategies, but most global ecosystem models do not distinguish between forest types or represent age-related dynamics adequately," Luo said. "So we felt it was important to clarify how these factors interact — not just for scientific understanding, but also for improving the models and assumptions that underpin real-world forest policy and carbon accounting."

Planted forests are those purposefully created by humans, such as those in the Great Green Wall. Natural forests, on the other hand, grow without human intervention.

The researchers used satellite data to track leaf area index, a measure of canopy density and a key driver of carbon uptake, to determine how fast the different forest types grew, and found a striking difference: Planted forests increased their leaf area 66% faster than natural ones.

Most of that difference was due to planted forests being, on average, much younger than the natural ones — and young trees grow faster than old ones. But even when comparing forests of similar age and growing conditions, the planted ones still grew 4.6% faster, and the difference was even more pronounced in mixed and evergreen forests.

This is largely due to how planted forests are managed. They tend to feature fast-growing species like eucalyptus and poplar and are often actively managed, with people removing competing vegetation and even fertilizing them. These interventions reduce competition for light, water, and nutrients, amplifying the fertilization effect of rising atmospheric CO₂.

This discrepancy peaks in planted forests when trees are around 30 to 40 years old and then declines noticeably after age 40. In contrast, natural forests grow more slowly but steadily, so have an advantage over the long term.

"Planted forests can be a powerful short-term tool for carbon uptake, but this advantage is temporary," Luo said. "For long-term carbon storage and resilience, natural forests remain irreplaceable."

Kevin Dsouza, who worked on reforestation models during his postdoctoral research at the University of Waterloo and was not involved in the new study, said the results make intuitive sense, as the sprawling leaves of young, fast-growing trees could lead to increased carbon take-up. But he is not sure that leaf area is the best measurement for tracking growth and carbon sequestration.

"It's not a bad proxy, but it doesn't give you the full picture," he said. "The canopy is just the top of the tree and the carbon is stored in all sorts of different places like wood, bark, roots and soil."

Another study of Chinese forests found that natural forests actually accumulate more carbon above ground than planted ones in their early years, Dsouza pointed out, so these results should be considered carefully alongside other factors.

Luo said the findings show that most global climate models are missing something when it comes to understanding how various forest types play a role in carbon sequestration and climate change.

"Land use management works in more subtle and specific ways than we had assumed," he said. "It is not just about planting more trees. It is also about when you plant them, what species you choose, and how you manage them over time."

Luo hopes these findings will help guide reforestation efforts, to ensure we get the most benefit from planting new forests to help mitigate the effects of climate change.

"Our work offers a more practical guide for forest-based climate action: when to plant, what to plant, how long the benefits last, and what current models are getting wrong. We hope that helps people make better decisions," he said.

Editor's note: A picture caption in this article was corrected at 5:16 ET on July 1 to say 66 billion trees had been planted.

It takes a dozen or so hours for the mushroom to kick in. Then, the hallucinations are unlike any others known to science.

On this trip, there are none of the heightened colors, breathing or pulsing objects, nor geometrical patterns typically reported by users of psychedelic substances. In fact, the hundreds of people who enter clinics in China's Yunnan province during each year's summer mushroom season tend to say their vision is clear and largely unaltered.

Well, aside from one major exception: nearly all users see visions of hundreds to thousands of highly-rendered miniature people, dressed in bright colors like elves, gnomes, clowns or other fairy-like figures. The hallucinated sprites wriggle under doors, dive off spoons into soup bowls and make lewd and mischievous gestures, among other strange behaviors.

These visions are reported by 90% of those who come down sick after consuming a single species of bolete mushroom, called Lanmaoa asiatica, in its raw or undercooked form. Yet despite decades of anecdotal reports, the fantastical claims were dismissed by western scientists as a form of "mushroom madness" — until Colin Domnauer, an undergraduate student taking an optional university module on funguses, caught wind of the rumors.

Domnauer, now a doctoral student at the University of Utah, made finding and analyzing the mushroom the purpose of his PhD, a goal that took him to China and the northern Philippines on the trail of a hallucinogenic compound that is likely completely unknown to science.

Live Science sat down with Domnauer to discuss L. asiatica, the bizarre revelations it could hold for how we perceive reality, and the barely-discovered fungal universe that surrounds us. Here's what he had to say.

Ben Turner: Let's start by introducing this mushroom. What is Lanmaoa asiatica?

Colin Domnauer: Lanmaoa asiatica is a species of mushroom from Yunnan, China. It was described to science only 10 years ago in 2015, so it's a relatively newly discovered species, but it was actually being sold in the markets in Yunnan for decades before scientists realized it was its own species.

Through the work I've been doing, we've come to the conclusion that this species is responsible for really strange reports of hallucinations that people are getting after eating wild mushrooms in China, and elsewhere in the world as well.

It's a species that grows with pine trees. It has a symbiotic relationship called a mycorrhizal relationship and so, for that reason, it's something that can't be cultivated artificially. And it's still only found in its wild habitats, so it's difficult to distribute in that sense. But it's still relatively common and popular in the places that it is found.

BT: The mushroom is growing in notoriety because of the uniquely bizarre hallucinations it's reported to cause. Let’s say I ingest a significant dose of raw or undercooked L. asiatica right now, what's my next week gonna look like?

CD: Alright, so we don't know exactly the amount of mushroom that's required to get this effect, because in all these cultures they're eating it accidentally, or they're eating it just as food, but they're not intentionally pursuing the psychoactive effects. These effects are seen as an accidental side effect of eating too much, or if they're not cooked enough.

But if you do have a substantial amount, what we do know is that after about 12 to 24 hours you're going to start getting Lilliputian hallucinations, which is a clinically defined syndrome that's characterized by seeing little people or animals all around your environment.

And these aren't like some vague hallucinations, these are like three-dimensionally-rendered, highly-detailed figures inhabiting your exterior world. And they're also interacting with objects in the real world — like crawling up chairs and tables or under doorways, people say. So there's a very strange and specific type of reality-grounded, projected hallucination.

Even to this day science doesn't understand what's going on in the brain to cause this, or how to treat it, and this mushroom is the only thing that we currently know of to reliably produce this effect.

BT: Okay, so immediately there's a lot I want to ask you. Firstly, these tiny people are pretty reliably reported, right?

CD: At first scientists dismissed it as a folk tale or something, because it sounds so impossible, but this is actually something that affects hundreds of people every year in Yunnan, China, and there's many hospital reports of people getting affected in this way. In fact, one study looked at about 400 cases in a year of people who were affected by this mushroom, and 90% of them said that they had these Lilliputian hallucinations. It's a hallmark symptom of this mushroom.

BT: From the case reports we have hundreds to thousands of clearly-rendered, often brightly-colored, gnome or fairy-like teeny people clambering about and crawling under things. What else are they doing? Are they talking to the people having the hallucinations, is there much interaction going on?

CD: That's something that's not as commonly reported, but it has been mentioned in a handful of cases, both in China and in other cultures where this phenomenon has been noted.

The little people are said to typically like teasing, playing with or harassing the person seeing them, so there is some level of interaction there.

They're typically viewed to be amusing, mischievous, that sort of attitude. They're not usually seen as threatening, although in a few cases people felt that way.

BT: Are there any other clinically-reported effects on the mind and body?

CD: Yeah, there are. The Lilliputian hallucinations are the most striking symptom, but there's other things as well. About 50% of people reported having some gastrointestinal upset after eating this mushroom. It's not clear exactly the severity of that, because this was just a statistic that was noted in these papers, and it's also not clear if it was caused by this mushroom specifically or other things they were eating in the meal. So these aren't really robust studies in that sense, they're just collecting data of people who happen to get these effects.

And then another key thing that a lot of people note is that they seem to be typically weakened, more tired and delirious, so this could give us a hint as to the mechanisms that this unknown compound is working through. So it sounds quite different from the known psychedelic compounds.

And it's not only because of that. This is actually something I forgot to mention, but these hallucinations can last several days long. So it's not something that is experienced over a few hours like other compounds.

BT: If people are hallucinating thousands of miniature people taunting them for several days, are there any injuries or fatalities linked to cases? Or is it just unpleasant and irritating, but harmless?

CD: Yeah, that's something I really was curious about, because it sounded like it must be quite harmful if it's something that's sticking around in the body for several days and having these strong effects.

But interestingly, all those hundreds of hospital reports reported zero deaths or fatalities. They also reported no abnormalities in vital organ function, so it seems to be physiologically safe. But then, at the same time, we don't know if that's because those people were admitted to the hospital and they were getting proper treatment, or if we only have the records of people that were committed to the hospital. So it might be a skewed sample.

BT: You mentioned that this mushroom is found in China's Yunnan province. And you personally also identified it in the northern Philippines too. I was wondering how widespread and integrated into the cultures of these regions it is. How widely known is it? Is it treated as a mischief of little significance, or has it been integrated into any religious practices?

CD: In all these places, the mushroom is viewed as a very prized edible. It tastes very good and has a great flavor, but it's never been integrated into any spiritual or religious practices for the psychoactive effects. The psychoactive effects are like an accidental side effect of the food, and they're viewed as sort of an amusing side effect of that. They're not something that they intentionally pursue, but it's also not something that they feel fearful of and avoid.

Everyone knows that this mushroom has this property and can make you see little people, but they'll continue to eat it anyway, because they're just not afraid of that effect. But they're also not pursuing it, if that makes sense. It's sort of a middle ground viewpoint they have.

BT: And that's so strange. I mean you're a scientist, I'm a science journalist, to me this thing is so fundamentally bizarre that I struggle to understand how it has flown under the radar for so long. It was only scientifically described 10 years ago, and even then without much mention of the psychoactive properties. Why are we only just talking about this now?

CD: The first reports of psychoactive boletes actually go back to the 1930s to 1960s in Papua New Guinea. That's actually a time before we even knew about psilocybin mushrooms, and yet psilocybin mushrooms have exploded in the last century to become globally popular.

But this mushroom went the opposite way and faded into obscurity. And I think the reason for that is twofold. One, the scientists who were initially studying this mushroom in Papua New Guinea were unable to isolate any psychoactive compounds and couldn't determine the species responsible for the effects. And secondly, because these symptoms sounded so bizarre and fantasy-like — seeing little people — I think this biased them toward believing that it wasn't possible.

In fact, they concluded that this whole phenomenon of "mushroom madness" was all just a social act, a myth, or a way for the people to behave in ways they ordinarily wouldn't. But they concluded the mushrooms were just like a scapegoat, they weren't actually physiologically active, it was just an excuse to do these things. It sounded so impossible, and we just couldn't figure out the chemistry of these mushrooms.

But since that time, we've had more reports coming from other cultures — from China, and now over the last two years from the Philippines. That's multiple independent cultures reporting the same specific type of hallucination.

And what I was able to show was that they were due to the same mushroom, verified by DNA sequencing. It wasn't just random attribution, it was the same species. That, to me, confirms that there's an underlying physical cause of this.

BT: How did you first hear about L. asiatica?

CD: I first heard about this when I was an undergraduate student taking an elective course about mushrooms, and the teacher briefly mentioned one paper writing about these mushrooms in China that have this effect.

It was written sort of as an anecdotal story. The mycologist was traveling in Yunnan, and the local people told him: "Oh, these mushrooms will make you see little people if you don't cook them." But in that paper he was unable to identify the mushrooms, and he shared his story and said this is something that needs more attention. I tried to look more into it after hearing about that, and I found that, amazingly, no-one was studying it. It had gone just unnoticed or dismissed for decades.

This sounded so weird and groundbreaking to me that, even if it had a small chance of being true, it was something worth pursuing and I needed to know everything I could about it. So that's when I decided to do a whole PhD research project to try to answer that question.

BT: So what did you do next?

CD: My first task was to go to China, because that's where it was most popular and most well known. And, upon getting there, it was immediately obvious that the local people knew much more about it than we scientists did. It was actually a very well-known and common phenomenon. Everyone there was very open and welcoming and happy to talk about everything they knew about this mushroom with me. So I learned a lot just speaking with the local people who were selling this mushroom.

I just asked them: "Which ones will make you see little people?" they pointed to them, and I collected them. After getting back to my lab here in Utah, I was able to sequence the mushrooms to determine their identity, and it turns out they were all this one species, so that was a first big hint.

BT: There must have been a moment when you went from hearing about this as a tall tale to realizing it was the real deal. What was that like?

CD: Going into my whole PhD was sort've a wild goose chase — a long shot. We didn't even know if this was real, and even when I made this trip to China, as I was traveling there I asked myself: "Am I even going to find anything? Is this going to be a whole waste of time?"

But it was immediately obvious that it was incredibly well known. As soon as I started talking with the locals and mentioning this mushroom, their faces lit up, and they started sharing amazing stories. It wasn't some obscure, lesser-known myth. It was a big part of their mushroom knowledge and practices, and that just built up over the days as I was in China, and talked to more people, and just confirmed how integral and well known this psychoactive mushroom is to them. It felt like it was too popular to be dismissed as a folk tale.

The real smoking gun then came a few years later when I heard some remarkably similar reports of mushrooms causing Lilliputian hallucinations in a completely different part of the world in the northern Philippines.

That really got my attention. I wanted to know if this is the same species as the one in China, or something completely different? But no-one had ever sequenced or studied the mushrooms in those regions, we just didn't know what it was. So I traveled there, went into the forest and on the last day was able to finally find the mushroom that the local people said was the one that made you see little people. At first when I collected it I couldn't tell if it was the same as the one in China.

When I got the DNA sequencing back it was one of the most exciting moments of my whole research. It was actually the same species as the one in China, which was completely unexpected, because that species, L. asiatica, was thought to only be found in China. Now we have a whole new record in a country that has independently discovered the same specific psychoactive properties belonging to it.

BT: Skipping forward to the more recent research that you've published this month, what have you found out about the pharmacology behind the mushroom's psychoactive properties?

CD: Just this month I was finally able to publish research that sequenced the whole genomes of not just L. asiatica, but actually all of the species in this group. I did that because I wanted to understand what psychoactive chemicals might be causing this effect and if it’s something that's found more widely in the mushroom kingdom, or only in this one species; so I needed to understand the whole evolutionary relationships and history of the group.

By sequencing the whole genome, we could look for genes within it that we know are responsible for synthesizing psychoactive compounds. For example, we know the genes that are needed to make psilocybin, and we looked for those genes and they were notably absent. We then confirmed this by looking at a chemical extract of the mushroom and screening all the compounds within it, finding again that there was no psilocybin.

There weren't even any known psychoactive compounds, so it seemed like this must be some new hallucinogenic compound waiting to be discovered, because there's nothing that matches anything in our database.

BT: What work are you doing now to isolate the psychoactive compound?

CD: It can be a long and painstaking process to go from a complicated organism that has hundreds of molecules in it to one causing a single effect. We've been screening the chemical extracts in mice, for example. We give them an extract of this mushroom, and we also give them an extract of a placebo or a blank control and we watch how their behavior changes. With L. asiatica, they behave strikingly differently than in the control, so that shows that there is a bioactive effect going on.

We then take an extract and split it into like 20 fractions, with each fraction containing a different subset of the mushroom’s chemicals. Then we test each of those 20 in the mice, and we see, okay, 19 of these have no effect, and then one of them does have an effect. That way we can narrow down the chemical responsible.

There's also other more complicated methods that we're pursuing. But still to this day we haven't definitively found the actual chemical responsible.

BT: Do you at least have a few candidates?

CD: I'll say this: We’ve narrowed down whatever is causing the activity in mice to a few candidates, but we don't know if the thing that's causing activity in mice is the same thing causing hallucinations in humans.

Mushrooms can have a variety of different bioactive effects, and there's going to be more testing needed to confirm that it actually has the specific hallucinogenic property. It could all just be a red herring that we're chasing, and so that's one of the reasons why it takes a long time to definitively determine an active biochemical.

BT: I know you’re approaching this from the mycology side, but the same visions being consistently reported between cases implies one or more regions of the brain responsible for seeing little people. What work has been done on the neuroscience behind Lilliputian hallucinations? Has anyone identified the regions of the brain it's hitting?

CD: I mean, that's a great question. As far as I know there's really nothing known about the parts of the brain that are being activated. Lilliputian hallucinations have been documented for over 100 years from causes outside of mushrooms — people get them sometimes during alcohol withdrawals or certain neurological conditions associated with old age, like dementia or Charles Bonnet syndrome.

But in all those cases, psychiatrists and neurologists don't really have a treatment for those people because they don't know how it works in the brain. If you don't understand the mechanisms involved, you can't treat it, so it remains a mystery to this day. Hopefully more neuroscientists can use this mushroom to study it, because that's one of the reasons it's remained mysterious. We didn't have a tool that could produce these effects reliably. It was all random, inconsistent occurrences.

But now, hopefully, this mushroom can provide a tool that can reliably produce these effects and give us insights into the brain and body mechanisms causing these Lilliputian hallucinations.

BT: DMT, LSD, magic mushrooms — most psychedelics usually hit serotonin receptors, yet weirdly there's no sign of that here. Is there any possibility it's doing something upstream with the same effect?

CD: I would say we're not sure, but I'll say that there are very unique effects of these symptoms — that they take 12 to 24 hours to kick in, and then can last several days — that are unlike any known receptor interaction classical psychedelics work through. So it might be something more complicated going on in the body than just a single receptor being activated.

BT: Have you spoken to anyone who has suspicions of what parts of the brain might be involved?

CD: I haven't. However, I'll say that the very striking visual hallucinations of something being completely integrated with the real world environment around you can be a great tool to understand the mechanisms of perception, and how we perceive reality in the absence of this drug.

I mean, this is... I don't know of anything else like this that can produce these very realistic hallucinations integrated with the real world. So, hopefully, it can give us insight into how we perceive reality normally.

BT: With other psychedelics, people report seeing real objects altered or patterns appearing that aren't there. But the source of all that is a warped version of stuff you're already seeing. Here, your visual field is unaltered, except, of course, that there are hundreds of mischievous tiny people fooling about in it.

CD: It's really different, yeah. Like you said, either the objects that are normally there are changed in some way, or people go to a different world in their minds, behind closed eyelids.

But to see, with your eyes open, the world as it normally appears with the addition of very realistically-rendered people, that others don't perceive, is really striking.

BT: So there have been scant reports of similar hallucinations occurring elsewhere. Papua New Guinea is a strong lead, right? Does that mean that L. asiatica is also there, or could there be another mushroom that's kind of having effects?

CD: That's one of the most exciting questions that I'm interested in. It still remains a big question mark. What mushroom in Papua New Guinea is causing these effects? There's no records of L. asiatica even occurring in Papua New Guinea, but it could be that mycologists just haven't documented it there. Mycology is still a very young discipline, and there's a lot of parts of the world where we still don't even know the mushrooms that exist there.

Or it could be a completely different mushroom, which would be exciting for its own reason — it would show that whatever compound is causing this is perhaps more widespread, and it's not just found in one species. More research needs to be done, for sure.

The cultural use and consumption of these wild mushrooms in Papua New Guinea has faded since the 1960s, when they were prevalent and reported. There's been no cases of this "mushroom madness" for decades. The reasons could be twofold, either the local people have lost that tradition and practice, or the forests have also been deforested. It's still a big question mark as to what's going on in Papua New Guinea.

BT: On mycology being a young field, the estimates for the world's fungal species that have been described float between 3% and 10%. It makes one wonder what else could be out there. Have you heard any other intriguing mushroom rumours?

CD: Who knows what else is out there waiting to be discovered. That’s what got me into this field. I was actually initially in astronomy, because I was so captivated by exploring the unknown. And then I realized there's a whole universe of life here on Earth that is still unexplored, the fungi, and so that's when I started studying them.

So I'm sure there are other crazy, promising, interesting fungi out there just like this. But I can't think of specific cases to cite. I mean, if it's unknown, it's unknown.

BT: I was wondering if you were close to performing the same trick twice.

CD: Yeah, hopefully others can.

BT: Do you think the window for them will exist for much longer? You mentioned these things grow symbiotically with trees through mycorrhizal networks. It's not just in Papua New Guinea where humans are chopping a lot of those forests down.

CD: Yeah, absolutely. Not only are the forests being lost, but also the cultures that have this traditional knowledge are also being decimated, so we're losing a lot of knowledge about the natural world that has taken thousands of years of experimentation to accumulate, and it's a tragedy.

It's like burning down a library, but the library contains millions of years of evolution and thousands of years of cultural knowledge. I'm sure there's mushrooms every day that are going extinct, and those might be holding promising new medicines or strange new drugs that can change our understanding of ourselves and the world, or have solutions to environmental problems.

It is definitely a race against time, and certainly the reason why I think fungal conservation and cultural conservation and respect is needed.

BT: Finally, I can’t get to the end of this interview and not ask you. Have you eaten raw or undercooked L. asiatica? Have you seen the tiny people?

CD: Of course I’ve been tempted to. But I haven't actually eaten it raw intentionally for two reasons. One, the effects last several days, and also apparently cause a delirium that might not be so pleasant. So, it's a pretty serious undertaking, I'd say.

Then secondly, we also just don't know anything about the dose of the mushroom that causes the effects, because people are just eating this in a meal, and then in some cases they get these psychoactive effects. We don't know how much is required, so there'd be a lot of careful experimentation of consuming raw mushrooms and then increasing the amount. That would take, I think, a lot of time and mushrooms to go through.

I'm certainly super curious, and that’s why I'm studying this in the first place. But there's already hundreds of reports out there, I don't feel like I need to prove anything. Personally, at this point, I just don't feel like it's not worth the commitment to be having these hallucinations for several days.

Editor's note: This interview has been edited and condensed for clarity.

Earth's underground fungal network is so vast that, if it were in outer space, it would span roughly 10% of the Milky Way if placed in a straight line, a new study finds.

These subterranean structures, called arbuscular mycorrhizal fungal networks, work in partnership with most of the world's land plants, feeding plants nitrogen and phosphorus in return for their carbon. Now, the first global map of this fungal network has revealed where their intricate branching structures are most densely packed.

In grasslands that are high-altitude or flooded grasslands, such as the Everglades in Florida, the top 6 inches (15 centimeters) of soil are especially dense, containing around 40% of the global fungal biomass. This highlights that undisturbed grasslands are an essential, reliable carbon sink, according to the research, which was published Thursday (June 11) in the journal Science.

"This is the most dense fungal forest on Earth, and they're under wild grasslands," study first author Justin Stewart, an evolutionary biologist at the Society for the Protection of Underground Networks, a scientific research organization specializing in fungi which form symbiotic relationships with plants, told Live Science. "It's changing the way that we're discussing how life is distributed on Earth."

"I hope this builds into the conversation for their protection because wild grasslands are going away quite quickly," Stewart added. "These are areas that people are really ripping up because it's much easier to rip up a grass than it is to rip up a tree."

For instance, the map revealed that some agricultural practices are decimating this underground network, with the topsoil in croplands containing roughly 50% lower densities, on average.

The hidden fungal forest

Arbuscular mycorrhizal fungi are made up of tiny branching threads called hyphae. These hyphal networks form two-way pipes to channel nutrients and carbon to and from plants, respectively. As a result, the fungi gobble up vast amounts of carbon. One estimate found they take in around 4.3 billion tons (3.9 billion metric tons) of carbon dioxide equivalent each year, representing roughly 11% of global fossil fuel emissions in 2021.

Even though these fungi are essential to Earth's health, it wasn't known how they were distributed around the world. "That's like saying we know every day 100 million cars move across Earth but we have no idea what road network facilitates that," Stewart said.

To establish the first global map showcasing the distribution and density of hyphal networks, Stewart and their colleagues compiled data from 16,669 soil cores collected in 322 previous studies. These cores provided data on hyphal density from both field studies and experiments in pots, with the field samples spanning every continent and nine biomes.

The team then used artificial intelligence to predict the distribution of arbuscular mycorrhizal fungi for every 0.4 square miles (1 square kilometer) of topsoil worldwide, using information on the climate, soil chemistry, vegetation and hyphal density.

The researchers found that there is an average hyphal density of 237 feet per cubic inch (4.4 meters per cubic cm) in land topsoil. If all hyphae were laid out in a straight line, the researchers estimated they would span approximately 68 quadrillion miles (110 quadrillion km). That's nearly a billion times the distance of Earth to the sun, or around 10% the width of the Milky Way galaxy.

Wild grasslands had the highest density, at 355 feet per cubic inch (6.6 meters per cubic cm), while cultivated trees had the lowest, at 204 feet per cubic inch (3.8 meters per cubic cm). Although the team could not specify which agricultural practices had the greatest impact on hyphal density, fungicides and phosphorus and nitrogen fertilizers could explain the relative sparsity in cropland topsoil, the authors wrote in the study.

Some regions of the world, such as those in tropical rainforests and deserts, need more sampling to reduce the uncertainty on the map. Stewart said researchers are actively working on filling in these gaps. "Within the next five years, this map will be updated and we're going to have a better picture of the distribution of these fungi," they said.

A global map of arbuscular mycorrhizal fungal network density and biomass was "urgently needed" and "can inform more efficient strategies for biodiversity conservation and restoration, agricultural management, and climate change mitigation," Andrea Genre, an expert in arbuscular mycorrhizal fungi at the University of Turin in Italy who was not involved in the research, told Live Science in an email.

This "seminal" research "makes part of the invisible visible," Edouard Evangelisti, a plant scientist at Côte d'Azur University in France who was not involved in the research, told Live Science.

The map is a "major milestone," Evangelisti said, and opens the door to investigating the functional importance of these gigantic underground networks, such as for drought tolerance and disease resistance. The dynamic nature of these fungi also needs to be investigated.

"The abundance of living hyphae is important, but for the carbon cycle, we also need to know how quickly these hyphae grow, die, and contribute to stable soil carbon," he told Live Science in an email.

One of the world's rarest trees, a cliffside plant with just one known individual left in the wild, may have a new chance at survival after scientists collected hundreds of seeds from the lone survivor's precarious home on Chile's Robinson Crusoe Island.

The tree, Dendroseris neriifolia, is native to the Juan Fernández Islands, a remote chain of volcanic islands about 420 miles (673 kilometers), from mainland Chile. Once found in lowland areas of Robinson Crusoe island, D. neriifolia has been pushed to the brink by habitat loss, erosion, invasive species, grazing animals, fires and historic forest clearing.

The genus Dendroseris has 11 species, with all populations, not just D. neriifolia in decline, Paulina Hechenleitner V., a plant taxonomist at the Royal Botanic Garden Edinburgh in Scotland, told Live Science via email. She added that no seeds from this genus had been stored in any seed back, until now.

Seeds from the last remaining wild tree were recently sent to the Millennium Seed Bank at Kew Wakehurst, a botanic garden in West Sussex, England, where scientists are conducting germination trials and storing material for long term conservation. X-ray analysis found 25 of the 29 seeds sent to Kew were potentially viable, and seven seedlings are now putting down roots inside the gardens, according to the Royal Botanic Gardens, Kew.

"Through this project, we hope to be able to produce more seed from the plants which we have growing now once they reach flowering age," Alice Hudson, the Millennium Seed Bank partnerships officer at Kew Wakehurst, told Live Science in an email.

The vanishing of an island tree

Hechenleitner said D. neriifolia's population has been declining for more than a century. The species was first described from material collected in the 1830s by Italian botanist Carlo Bertero, one of the early botanic explorers of the Juan Fernández Islands.

"Historical accounts indicate that the species was still relatively common in parts of its range in the late 19th century, although local extinctions were already being reported," Hechenleitner said.

While a field expedition in 1980 found seven trees, each up to16 feet (5 meters) tall, only one tree remains today, monitored by Chilean park rangers with CONAF, Chile's national forest agency.

Climbing the cliffside

Collecting seeds from the tree is dangerous, highly specialized work. Simply getting to the tree is a challenge.

"It is a rocky volcanic island with no car [accessible] road," Hechenleitner said. "The only access is by taking a 4 hour journey and afterwards, a 2 hour climb."

The last known wild D. nerifolia clings to a steep cliff and is supported by ropes to keep it from falling. Each March, when the seeds mature, park rangers climb along the trunk to reach the flowering branches to catch mature seeds in nets. However, this is the first time the seeds have gone to a bank."There are lots of different ways you can collect seeds from a tree, the best method depends on many factors including the height of the tree," Hudson said. "Seeds should be collected at the point at which they naturally release from the tree, this means you can often use methods like getting a throw line over a branch and gently shaking the tree to release the seeds for collection."

Climbing remains the main option for very tall or inaccessible trees, though new tools like drones may help with seed collecting in the future.

Overcoming biological barriers

Even with seeds looking viable, conservationists are worried about genetic bottlenecks, low fertility and inbreeding in the wild. Although D. neriifolia can self-fertilize, seed production may remain limited if flowering branches are sparse.

"Seed conservation offers a back-up — if anything happens to the plant in the wild, there are seeds stored in the bank which we know how to germinate, so the species is not lost," Hudson explained. "It spreads some of the risk."

Seed banks also allow scientists to study the germination process up close and in a controlled environment.

"Many species can have complex dormancy or germination requirements so it means that we can research the best ways to germinate seeds, sharing our knowledge to help others to reintroduce plants back into the wild or use them for scientific research finding future foods or medicines," Hudson said.

Now, scientists hope the young D. neriifolia plants at Kew Wakehurst will eventually flower and produce even more seeds to store. The knowledge gained from growing them could help Chilean conservationists develop protocols for future restoration.

"These will be able to be used in Chile with future seed produced from the remaining tree to hopefully produce plants for restoration efforts or other ex-situ living collections in Chile," Hudson said.

Do you know where pumpkins and blueberries come from? Find out with our fruits and vegetables quiz!

Mangrove forests, long considered among the world's most threatened ecosystems, are now showing signs of global rebound, a new study reports. These findings mean experts are cautiously optimistic about gains in coastal protection.

The results are based on 40 years' worth of satellite data, which shows that mangrove forests are more resilient than expected. Gains over the past 16 years have outpaced losses, leaving the world with about a 1% net decline in mangrove area since the 1980s, far less than previous estimates suggested. The findings were published Thursday (June 4) in the journal Science.

Historically, mangrove populations have been declining mainly because coastal development, aquaculture and agriculture have cleared large areas of mangrove forests. Pollution and rising sea levels have also weakened these ecosystems, shifting the balance of saltwater and freshwater that these trees need to survive.

"After decades of loss, we're finally seeing a global turning point for mangroves," study first author Zhen Zhang, a postdoctoral scholar in the School of Science and Engineering at Tulane University in Louisiana who specializes in mangrove forest coverage, said in a statement. "This highlights their strong resilience and their potential as a powerful nature-based solution for climate mitigation and coastal protection."

Eyes in the skies

Mangroves make up salt-tolerant forests full of shrubs and trees that grow along tropical and subtropical coastlines. They protect coastal communities by acting as a natural barrier against storms, strong winds and flooding. Their dense root system helps slow down storm surge and reduces erosion by holding shoreline soil in place. Mangrove forests also help support ecosystems because their tangled roots provide safe habitats where fish, crabs, shrimp and other marine animals can grow before moving into open waters.

These forests are also important in the fight against climate change, as they store large amounts of carbon in their trees, roots and deep muddy soils, helping to reduce the amount of carbon dioxide in the atmosphere.

To track the changes in mangrove populations, researchers at Tulane's Mangrove Lab used long-term observations from the Landsat program, a joint mission between NASA and the United States Geological Survey (USGS). The researchers combined Landsat's digital eyes with high-resolution satellite imagery from the European Space Agency's PlanetScope to validate the mangrove maps.

"Ground fieldwork is extremely valuable, but it is often costly, and doesn't allow this large-scale perspective," Daniel Friess, a professor of Earth and environmental sciences at Tulane and the director of the Mangrove Lab, told Live Science in an email. "Satellite observations allow us to fill these gaps and detect long-term changes in places where field measurements are sparse or unavailable."

The team used machine-learning techniques to create baseline mangrove maps for the 1980s, 2010 and 2021, then applied change-detection methods to generate annual records from 1984 to 2023. Those maps allowed the researchers to calculate yearly mangrove losses and gains across the globe and identify a shift from a global decline before 2010 to a net gain after 2010.

The rebound was driven by both restoration and natural expansion, according to the researchers. In some places, mangroves have recolonized abandoned aquaculture ponds. In others, the forests have spread onto newly formed coastal mudflats, particularly in river deltas where sediment creates favorable conditions.

Along the U.S. Gulf Coast, warming temperatures have also encouraged mangroves to expand into higher-latitude areas. Louisiana has seen an overall increase in mangrove area over the past 40 years, while mangroves in the Mississippi River Delta began increasing more sharply after 2012, the researchers said.

But the findings, while encouraging, do not mean mangroves are safe. Friess said continuing losses must be halted so that mangrove forests can continue to rebound.

"We may have underestimated the state of the world's mangroves, " Friess said, as there is evidence that the forests are naturally regenerating and expanding. "It means that if we can halt continuing loss through conservation, then we may see an even bigger gain in the world's mangroves."

Recovery remains fragile

A separate study published Wednesday (June 3) in the journal Earth's Future warned that rising seas could reduce the amount of carbon dioxide mangrove forests store and, in some cases, turn them from carbon sinks, storing more carbon than they emit, into carbon sources, in which they would emit more carbon than they could store.

The researchers used a model that combined water flow, sediment movement, carbon storage, and mangrove growth and dieback — when a large number of mangrove trees rapidly die off — to get a bigger picture of mangrove ecosystems. They found that sea level rise may increase carbon storage in some localized areas at first, but whole-forest carbon storage is likely to decline over the next century, meaning more carbon will be kept in the atmosphere, adding to the effects of climate change. Mangroves need a certain amount of tidal flooding to survive, but too much flooding could cause them to disappear.

The findings underscore the ongoing need to protect existing mangroves so they can continue protecting ecosystems and sequestering carbon. Friess said he hopes global gains continue, but the effects of climate change could lead to losses instead.

"While we hope that net gains in mangrove area will continue, it may be challenging to maintain this trajectory in many places under climate change," he said. "So we need to focus on conserving and restoring mangroves now in order to give them the best chance in the future."

It's a plotline that has haunted science fiction for decades: Humans become infected by plant pathogens, causing illness, death or a zombie-like state. But is there any truth to this idea? Can plant germs really cross over to people?

The short, disturbing answer is yes, experts told Live Science, but it's incredibly rare.

Plant pathogens are viruses, bacteria, fungi or other microorganisms that cause disease in plants, usually by infecting cells, reproducing, and spreading within and feeding on plant tissues. This can cause cell death, wilting, peculiar growths and discoloration; interrupt plants' ability to photosynthesize; stunt their growth; and, ultimately, kill them. Fungi cause an estimated 85% of plant diseases overall.

Much of what we know about how the human body functions makes it seem unlikely that these pathogens could invade our bodies, too. "It is extremely rare for a pathogen to jump from a plant to a human or vice versa because our biological architectures are fundamentally different," Dr. Soma Dutta, a physician and medical microbiologist at Apollo Multispeciality Hospitals in Kolkata, India, told Live Science over email.

Plant pathogens have evolved to breach the thick, rigid walls of cellulose or hemicellulose inside plants. By contrast, human cells are protected by lipid membranes, which are lined with receptor proteins that can initiate an immune response. Plant pathogens generally don't have the tools to break through these membranes, Dutta explained.

Besides, for most plant-specific fungi and bacteria, which typically survive in temperatures of up to 77 degrees Fahrenheit (25 degrees Celsius), our much higher bodily average is uncomfortably hot. "The human body is essentially a furnace," Dutta said. "The heat denatures their proteins and prevents them from causing infection."

Deadly pathogens

But there are exceptions. In 2023, Dutta and colleague Ujjwayini Ray, a consultant microbiologist at Apollo Multispeciality Hospitals, Kolkata, published a case report abouta patient who had developed a persistent cough and sore throat, was struggling to swallow, and was not eating, with seemingly no cause. When doctors examined him, they found a pus-filled abscess developing beside his windpipe. An exam revealed spores from Chondrostereum purpureum, a fungus that causes silver leaf disease in plants.

The researchers discovered that the 61-year-old was a plant mycologist, someone who studies the relationship between fungi and plants. "For years, his professional work involved direct, intense contact with decaying wood, mushrooms, and various plant fungi. This provided a clear pathway for inhalation of spores," Dutta explained. She and her colleague hypothesized that the spores had somehow managed to "hide from or resist" phagocytosis, a crucial phase of the human immune response, allowing them to establish a colony and spread. But to Dutta, the fungal infection remains a puzzle, because despite being a cool-weather fungus, it had managed to survive the higher temperatures of the human body.

With a course of antifungal tablets, that patient recovered fully. But that's not always the case; in the rare situations where plant pathogens cross over into humans, they typically affect those with weakened immune systems, which can result in death. Many of these pathogens thrive in warm, moist, stable environments, and they have been detected in catheters and breathing equipment in hospitals, which is how vulnerable patients can become exposed.

For example, the bacterium Pantoea agglomerans causes disease in a range of food crops ‪—‬ like rice, maize and sorghum ‪—‬ and if it gets into the human bloodstream, it can be deadly. Another type of bacteria, Burkholderia, causes rot in onion and rice, and research has documented cases where this germ has infected cystic fibrosis patients, causing pneumonia, blood poisoning and death. An investigation into several strains of B. cepacica, found that the microorganisms could surpass the defensive cilia and mucous lining the airways and get into and spread within the lungs.

Another bacterium, Pseudomonas aeruginosa, causes soft rot in plants like lettuce and potatoes. But it has also been found in hospitals, where it has passed to immunocompromised patients with severe burn wounds, cancer or AIDS, causing infections in their urinary tracts, blood and lungs.

Plant viruses

Plant viruses are generally believed not to pose a risk to humans because of the unique mechanisms they use to infect plants, but scientists have unearthed some compelling clues that we might be vulnerable to the diseases they can trigger. In 2014, Philippe Colson, a professor of medical virology at Aix-Marseille University in France, delved into the strange case of pepper mild mottle virus, a highly contagious plant pathogen that causes pepper plants to shrivel up. Peppers are widely consumed, so Colson and colleagues studied the stool samples of over 400 people and found the RNA of the virus.

Individuals who had the virus in their stools were significantly more likely to have symptoms of disease. "We were able to find a correlation between the presence of this virus in human stools and the symptoms of fever and pruritus [itchy skin]," Colson told Live Science. Although they didn't show a definite causal link ‪—‬ the symptoms may have been triggered by something else in the food ‪—‬ "it made us question whether there could be an interaction with our body, and whether or not it could be pathogenic in some cases," he said.

The study also showed that the affected patients' stools contained antibodies specific to the pepper virus. The virus's ability to withstand the human gut suggests it is highly resilient; in fact, pepper mild mottle virus is so robust that it's been considered for use as an indicator of human fecal pollution in waterways.

Colson is also intrigued by tobacco mosaic virus, which leaves a distinctive pattern on tobacco leaves that causes shriveling, affects their ability to photosynthesize, and stunts their growth. Strikingly, previous research into this virus had "looked at people that had lung cancer, and they found the virus in their biopsies," Colson said. Colson's own research has detected tobacco mosaic virus in several cigarette brands and in the saliva of people who smoked them. This raises tentative questions about whether the virus can travel into human bodies through cigarettes and possibly play a role in smoking-related cancers, Colson said.

For now, research on viral plant pathogen crossover into humans is limited, with the central puzzle being how they might infect humans if they do; plant viruses typically enter plant cells through a hole in the cellulose wall, whereas viruses in humans have to interact with a series of receptors around the cell before they can break in, Colson explained. Yet the important implications of potential plant virus infection in humans makes him "quite confident that this is a field that will expand in the near future."

The research so far shows that it's highly unusual for any plant diseases — fungal, bacterial or viral — to seriously, or fatally, develop in people who don't already have severely compromised immune systems. Crossovers are "extremely rare," Dutta noted, but she believes that our changing planet means plant pathogens deserve continued attention and research.

"The most significant barrier of the human body is temperature, which is being eroded by climate change and global warming," Dutta said. As global temperatures rise, plant pathogens may be finding ways to adapt to these warmer conditions, equipping them to survive in our bodies.

"The final message regarding plant-to-human crossovers is one of evolving vigilance," Dutta said. "While the biological barriers between plant and animal cells remain very strong and not easily breakable, the case of the Chondrostereum purpureum infection serves as a vital reminder that 'rare' does not mean 'impossible.'"

When the dinosaur-killing meteor hit Earth 66 million years ago, many flowering plants transformed into "hopeful monsters" to endure the resulting environmental crisis. Now, new research suggests that this was not the only time these plants responded this way. In nine separate events over the past 150 million years, flowering plants have duplicated their whole genome to give themselves a better chance of survival in the face of catastrophe.

The work could help scientists understand what will happen to flowering plants, which include most of the crops people eat, as the climate changes and organisms endure another environmental upheaval.

"Waves of whole genome duplications correlate with important geological events or periods in evolution," Yves Van de Peer, a genome biologist at Ghent University in Belgium and a co-author of the paper, told Live Science.

For almost a century, whole-genome duplication has puzzled scientists. Organisms that have more than two sets of genomes are called polyploids. Humans, which have two sets of chromosomes, are diploids. Polyploids are sometimes called "hopeful monsters" because they are "monstrously" different from their parent organisms — but have the potential to survive conditions that their parents cannot and, therefore, offer hope to a species.

But these organisms are a paradox, Van de Peer said. "When you go outside and start collecting plants, there is a very high chance that you will collect polyploid plants," which are plants that have undergone a whole genome duplication, he explained. "Nevertheless, when we analyze plant genomes, we find very little evidence for many whole-genome duplications that have survived in the longer term."

That's because whole-genome duplication is a risky gamble for a plant. "It's not an easy thing, from a cell biology point of view, to deal with," he said. "There are costs involved," such as larger cells, reduced fertility and other consequences. For this reason, polyploids are often seen as evolutionary dead ends because these mutations are unlikely to endure.

Many of the crops we eat are polyploids that humans have subconsciously selected over time because of their bigger fruit or ability to survive environmental stresses, Van de Peer said. But polyploid individuals struggle to compete with other members of their species when conditions are stable, so they die out during good times. But during difficult periods, polyploids may be able to adapt better, he said.

"Bursts throughout the history of plants"

In the new study, published Friday (May 8) in the journal Cell, the researchers analyzed the genomes of 470 flowering plants, called angiosperms. They hunted within those genomes for the remnants of whole-genome duplication. Ultimately, they discovered 132 independent duplication events over the past 150 million years and used information from fossilized plants, among other methods, to date when these events took place.

In 2009, Van de Peer and colleagues showed that duplication in a handful flowering plant species clustered around the meteor that killed the dinosaurs. However, the latest research shows that the blossoming of polyploid angiosperms was not a one-off event; it has occurred many times in the past 150 million years. The researchers identified at least nine clusters of duplication incidents, all of which corresponded to important environmental events.

"We see clusterings of whole genome duplications in time, and every time it corresponds with a described, important geological event, whether it's a global cooling period, whether it's a global warming period, or whether there's an extinction event," Van de Peer said.

Kevin Bird, a researcher who studies the evolutionary genomics of polyploids at Kew Garden in London and was not involved in the new study, said the new research helps build on past work. "The study's findings are a very exciting hint at how life survives and evolves through the most extreme periods in our planet's history," he said. "Given that the initial findings in 2009 were about a single cluster of ancient duplication events around 60-70 million years ago, it was a shock that they discovered evidence for as many as nine of these bursts throughout the history of plants."

However, he noted that the research should be a starting point for further investigation. "Overall, the work is done very carefully with some of the best methods currently available, but there is always a lot of uncertainty when you're projecting back hundreds of millions of years in the past," Bird told Live Science.

In the future, as the climate changes, research into polyploids is likely to become increasingly important, scientists say.

"Polyploids are better able to cope with stress, and stressful conditions can also induce polyploidy," said Douglas Soltis, a biologist at the Natural History Museum of Florida who was not involved in the research but who collaborates with Van De Peer. "The Anthropocene [human era] will be — and probably already is — a time of stress that will induce polyploidy and also select for polyploids."

Bird agreed that climate change could trigger another burst of genome duplications, but he noted that it would take millions of years to see how this burst will shape plant evolution. "What we might expect to see in the present is that polyploid populations are better able to tolerate the weather volatility, intensification and habitat degradation brought on by climate change and other human disturbances to habitats," he said.

Van De Peer and his team are artificially making polyploid plants and investigating how they respond to stress. "There must be a stress advantage in the polyploids, but there is so much that we still don't know about that," he said.

See how much you know about natural selection with our evolution quiz!

Mangrove forests around the world provide a largely overlooked nitrogen-pollution cleanup service — one that, if humans had to pay for it, would cost $8.7 billion per year, a new study estimates.

Mangroves are salt-tolerant plants that grow between the high-tide and low-tide marks in tropical and subtropical coastal regions. Their tall, tangled roots trap sediments rich in microbes that break down nitrogen in the water into nitrogen gas (N₂) and nitrous oxide (N₂O), effectively removing this nutrient from the ecosystem.

Researchers were aware that mangrove forests are valuable carbon sinks and provide a host of other ecosystem services, including coastal defense against storm surges and a buffer against erosion. But these forests' ability to remove nitrogen is poorly understood, despite the havoc that nitrogen pollution is known to wreak in aquatic ecosystems, the authors of the new study told Live Science.

"We're still really in the infancy of trying to understand what is driving this nitrogen removal," Benoit Thibodeau, an assistant professor in the Department of Earth and Environmental Science at The Chinese University of Hong Kong, said in a joint interview with his co-author Ziyan Wang, a doctoral student in environmental science at the same university. "You're taking reactive nitrogen … and you're removing it to the atmosphere as N₂, which is nonreactive and has a residence time of thousands of years."

Nitrogen pollution is caused by excess nutrient runoff into water systems due to human activities such as agriculture. Between 2002 and 2010, this runoff amounted to 35.9 million tons (32.6 million metric tons) of nitrogen per year in freshwater ecosystems. This pollution promotes algal growth, leading to blooms that massively reduce oxygen availability for other species and release toxins into the water that can make animals and people sick.

Mangroves forests cover less than 0.1% of Earth's land surface, but they remove about 960,000 tons (870,000 metric tons) of nitrogen from water systems each year, the new study found. That's roughly equivalent to the mass of 650 giant sequoia (Sequoiadendron giganteum) trees — but optimal conditions for mangroves could boost their removal capacity to more than 5.5 million tons (5 million metric tons) per year, which is equivalent to the weight of over 4,000 giant sequoias. The findings were published April 29 in the journal Earth's Future.

Thibodeau and Wang analyzed the results of 51 previous studies, as well as measurements they took themselves, to estimate global nitrogen-removal rates in mangrove forests. They divided the data into actual removal rates, which are those observed in nature, and potential removal rates, which capture the amount of nitrogen that mangrove forests could soak up if temperature, salinity and nitrogen levels were optimal.

Then, the researchers calculated averages for the actual and potential rates — and these, together with a global mangrove area estimate of 52,459 square miles (135,869 square kilometers), yielded an actual removal rate of 960,000 tons per year and a potential removal rate of over 5.5 million tons per year.

Microbes in mangrove forests remove nitrogen via two main pathways: denitrification and anaerobic ammonium oxidation (anammox). Denitrification transforms nitrate in the water into nitrogen gas and nitrous oxide, which is a greenhouse gas. Anammox, on the other hand, converts nitrite and ammonium into nitrogen gas, which makes up 78% of the atmosphere and is not a greenhouse gas. These pathways work best with relatively high nitrogen concentrations, but there is a threshold past which removal slows, according to the study.

These pathways also occur in seagrass meadows and other coastal environments, but mangrove forests are especially good at removing nitrogen because their sediments are oxygen-poor, which promotes the right kind of microbial activity, Wang said.

Similar to carbon credits that people can purchase to offset their emissions from activities like flying, the researchers used a market-based credit approach to calculate the economic value of nitrogen removal in mangrove forests. Based on what municipalities in countries like Australia and the U.S. pay to get rid of nitrogen in their water systems, Thibodeau and Wang settled on a price of just over $10,000 for every metric ton of nitrogen removed anywhere in the world.

"Carbon has a very mature credit market now, but for nitrogen, it's not that mature," Wang said. "We did a very early investigation about how different markets, or different industries, deal with this kind of nitrogen pollution."

At the current rate of nitrogen removal, mangroves' cleanup service is worth $8.7 billion per year globally. If removal rose to 5.5 million tons per year, it would be worth around $57 billion annually, according to the study.

The researchers also calculated the economic value of carbon sequestration in mangrove forests and found it was 12 times smaller than that of nitrogen removal. Notably, carbon sequestration is also less stable than nitrogen removal is, because mangroves store carbon in sediments that can be disturbed. On the flip side, mangrove forests convert nitrogen in the water mostly into nitrogen gas, which stays in the atmosphere, Thibodeau said. Nevertheless, mangrove forests "have a very high rate of storage of carbon compared to other ecosystems," he added.

Mangroves are mostly threatened by sea-level rise and land clearance for infrastructure, Thibodeau said. The results highlight that "we're not only losing space or nature, but we're also losing a very important financial value."

Mangroves have a relatively high heat tolerance, but rising global temperatures could alter how the microbes they host consume nitrogen, Wang said. Specifically, these microbes may start to rely more on denitrification, which could release more of the greenhouse gas N₂O than at present.

Some fungi can produce proteins that freeze water, which may allow them to reach into the atmosphere and trigger rain. Now, scientists have discovered the secret to this process: a gene from ancient bacteria.

Researchers have long known that some bacteria have proteins in their cell membranes that allow them to freeze water at relatively high temperatures, about 23 degrees Fahrenheit (minus 5 degrees Celsius) ‪—‬ a process known as ice nucleation. Certain species of fungi can do this as well, but much less was known about how it worked in that kingdom of life.

"We just wanted to figure out how this works," said Boris Vinatzer, a microbiologist at Virginia Tech and co-author of the new study, which was published March 11 in the journal Science Advances.

Vinatzer and his colleagues studied the genomes of two strains of fungi in the Mortierellaceae family to find their ice-nucleating protein. They had a couple of leads: They knew the protein was secreted into the environment rather than stuck to the fungal cells, and they knew roughly how big it was. So they looked for genes that had those characteristics and were similar to known bacterial ice-nucleating proteins.

They were surprised to find a candidate that was almost identical to a bacterial gene called InaZ. And when they transferred that fungal gene into a yeast cell, the yeast gained the ability to create ice as well.

"We confirmed that that particular DNA fragment actually makes ice nucleation proteins," he told Live Science.

This suggests that, at some point in the past, perhaps millions of years ago, an ancestral fungus acquired the gene from its bacterial neighbors ‪—‬ a process known as horizontal gene transfer ‪—‬ and then made it its own.

Less clear, however, are how the fungi are using this ice-making ability and what evolutionary advantage it gives them. "We really have no idea so far," Vinatzer said.

Bacteria that have ice-nucleating proteins are often ones that attack plants, such as Pseudomonas syringae, which infects corn. Scientists think these bacteria use the ice-forming proteins to damage the plant, allowing nutrients to seep out or the bacteria to invade.

One of the fungi in the new study was from lichen, a hybrid colony of fungus and algae that grows on rocks and trees. Vinatzer speculated that the ice-nucleating proteins may allow the fungus to pull water from the air, thus providing a necessary-but-scarce resource for the lichen.

"On mornings when there is high humidity and low temperatures, the fungal proteins can trigger a frost on the lichen that then melts and provides water later in the day," he said.

But perhaps the most intriguing aspect of these ice-making bacteria and fungi is that they may be able to influence the weather, seeding the clouds to call down rain.

Ice-forming bacteria like P. syringae are known to be part of the water cycle and play a significant role in precipitation. They get swept up into the clouds by wind or evaporation, where their ice-nucleating ability generates tiny crystals that eventually get large enough to fall as rain or snow. It seems likely that the ice-nucleating proteins secreted by fungi undergo a similar process, Vinatzer said.

Because a single fungus can secrete many proteins, with each acting as an individual ice nucleus, there may be many more of them in the clouds than there are rain-making bacteria. "That suggests fungi may actually be more important than bacteria in influencing the weather," he said, which could benefit not only the fungi on the ground but the entire ecosystem.

These newly discovered fungal proteins could be useful for humans as well, Vinatzer suggested. Cloud-seeding operations currently use a toxic chemical called silver iodide to generate ice crystals, but maybe it could be replaced with a benign organic protein.

"These proteins could be an alternative to toxic silver iodide," Vinatzer said. "If we can figure out how to produce them, why not use them instead?"

Scientists in Australia are in a desperate race to rescue a newly identified "zombie tree" before it vanishes from Queensland's rainforests.

They discovered that the tree, Rhodamnia zombi, can no longer produce flowers, fruit or seeds ‪—‬ leaving it alive but unable to propagate itself in the wild. The zombie tree, which was just discovered in 2020 and was described as a new species last year, is suffering from a fast-spreading fungal disease called myrtle rust.

"Left to its own devices, the trees in the wild really will be the living dead," lead author Rod Fensham, a professor in the University of Queensland's School of the Environment, said in a statement.

In a study published Dec. 11, 2025, in the journal Austral Ecology, researchers warned that R. zombi and 16 other rainforest tree species are under attack by this fungal pathogen and could be extinct within a generation without proper intervention.

Fungal fatalities

Myrtle rust, which is caused by the fungus Austropuccinia psidii, was first detected in Hawaii in 2005 and in Australia in 2010. Since then, its spores have spread widely as they are carried by wind, birds, people, machinery and insects.

"There's very little you can do about stopping the spread," Fensham told Live Science. "The Achilles' heel with myrtle rust is that it needs a certain kind of environment. It needs to be a humid world, not too cold either … Where I live in Brisbane, in the middle, is the perfect environment for it."

Myrtle rust is native to South America, where the native plants that co-evolved with the fungus developed resistance to it. The disease is called myrtle rust because the fungus attacks plants in the myrtle family, Myrtaceae, which includes eucalyptus, tea trees and other Australian rainforest species. Myrtle rust produces powdery yellow, orange or brown spore pustules — which look like rust — on infected plant tissue, slowly killing the plant by draining it of nutrients.

Because Australian species have evolved little or no resistance against the pathogen, they are what Fensham calls "naive hosts." "Humans were a naive host for the coronavirus," he said, "and this is similar."

To determine how widespread the myrtle rust was, the researchers revisited vulnerable rainforest populations in the wild. By surveying sites across eastern Australia, the team tracked which species were still producing flowers and fruit, which ones had stopped reproducing, and which populations had already died out.

Those species included the zombie tree. When the team revisited known wild populations of R. zombi, they found that about 10% of the populations had already died out and the remaining infected trees were no longer producing flowers or fruit.

"Myrtaceae is a monstrous family in Australia, [and] it's a small subset we've come to realize is in real trouble as a result of this disease," Fensham said. "So I guess it could be worse if the intolerance was more widespread in that huge group of plants. But it's bad enough as it is."

How to rescue a zombie

Because infected wild trees are no longer reliably making seeds, scientists are cloning the surviving plants using cuttings that can then be raised in nurseries and later moved to safer areas where the climate is less favorable to myrtle rust.

Another option is to use fungicide to keep trees in infected areas alive long enough for the plants to produce seeds. Scientists may then be able to identify seedlings that show more tolerance to myrtle rust. In the best-case scenario, those hardier plants could be returned to the forest someday.

"That sounds like a real long shot," Fensham said. "But actually, all the steps … have been done by enthusiastic people in the last few years. There's a real will and capability of rescuing these trees."

Fensham said researchers are looking into a tree-saving treatment that works similarly to a vaccine. "There's some … attempts to develop an RNA vaccine," he said. "Different variants [are] evolving, as we speak, that might have different tolerances."

However, he said the more realistic plan is to focus on cultivating cuttings from the surviving plants in a safe environment. "The species needs time and space without being constantly walloped by myrtle rust to hopefully express some resistance," he said in the statement.

Long before dinosaurs roamed the land, Earth looked very different from the planet we know today. Around 500 million years ago, most of Earth's surface was bare rock and dry soil. There were no trees, no grass and no flowers. Life existed almost entirely in the oceans.

Then something amazing happened: Plants began to grow on land.

This moment was one of the most important events in Earth's history because it changed the planet forever. As a geoscientist, I am interested in changes in the diversity of flora and fauna — that's plants and animals — over time.

Predecessors of plants lived in water

The story of plants begins in the water. The earliest plantlike organisms were simple, tiny green life-forms such as algae. You can still see algae today as seaweed along beaches or as green slime on rocks in ponds.

Algae have lived in Earth's oceans and lakes for over 1 billion years. They can make their own food, using sunlight, water and carbon dioxide to create sugars. This process is called photosynthesis; it releases oxygen — the gas we need to breathe — as a byproduct.

At first, Earth's atmosphere had very little oxygen. Over millions of years, photosynthesizing organisms like algae and some bacteria slowly released oxygen into the air. This change, sometimes called the Great Oxygenation Event, made it possible for larger and more complex life to evolve. Without oxygen-producing organisms, animals, including humans, could never have existed.

Scientists believe the first true plants evolved from green algae around 470 million years ago. These early plants lived in shallow water near shorelines, where conditions changed often. Sometimes they were underwater, and sometimes they were exposed to air. This habitat helped them slowly adapt to life on land.

Getting a foothold on dry land

Moving onto land was not easy. Water plants are supported by water and can absorb nutrients easily, but land plants faced new challenges. How would they avoid drying out? How could they stand upright without floating? How would they get water and nutrients from dry ground?

To survive, early plants evolved important new features. One key adaptation was a waxy coating, called a cuticle, which helped keep water inside the plant. Plants also developed stronger cell walls that allowed them to stand upright against gravity. Simple rootlike structures, called rhizoids, helped anchor plants to the ground and absorb water and minerals from the soil.

The earliest land plants were very small and simple. They looked similar to modern mosses, liverworts and hornworts, which still grow today in damp places like forest floors and stream edges. These plants did not have true roots or stems, and they stayed close to the ground. Fossils of early land plants, such as Cooksonia, date back to about 430 million years ago and show small branching stems only an inch or two tall.

Even though these plants were tiny, they had a huge impact on Earth. As plants spread across land, their roots helped break down rocks into soil, a process called weathering. This created richer soil that could support more life.

Plants also released more oxygen into the atmosphere, improving air quality and helping animals breathe. Plants created new habitats and food sources, allowing insects and other animals to move from water onto land.

Increasing complexity across millions of years

Once plants became established on land, evolution continued. Around 420 million years ago, plants evolved vascular tissue: tiny tubes that transport water and nutrients throughout the plant. This adaptation allowed plants to grow taller and stronger because water could be moved upward from the roots to the leaves. These vascular plants included early relatives of ferns and club mosses.

With vascular tissue, plant life really started to flourish. By about 360 million years ago, vast forests covered much of Earth. Giant ferns and treelike plants, some over 100 feet (30 meters) tall, dominated the landscape. Over time, dead plant material from these forests was buried and compressed, eventually forming coal, which people still use as an energy source today.

Another major step in plant evolution was the development of seeds, around 380 million years ago, found in seed ferns. Other seed plants, such as early conifers — a group that includes modern pine trees — could reproduce without needing water for fertilization. Seeds protected plant embryos and allowed plants to survive harsh conditions like drought or cold.

The most recent major plant evolution happened around 140 million years ago, when flowering plants, what scientists call angiosperms, appeared. Flowers helped plants attract animals like insects and birds, which spread pollen and seeds. Fruits developed to protect seeds and help them travel. Today, flowering plants make up most of the plants we see, including trees, grasses, fruits and vegetables.

The first plants didn't just survive; they transformed Earth. They changed the atmosphere, built soil, and created ecosystems that allowed animals to thrive on land. Thanks to plant evolution, Earth became a green, living planet full of diverse life.

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

Fruits and vegetables quiz: Do you know where pumpkins, blueberries and broccoli come from?

Canada could remove more than five times its annual carbon emissions from the atmosphere by the end of the century by planting trees along the northern edge of its boreal forest, a new study suggests.

In recent decades forests have slowly moved north in response to climate change — in particular the taiga area on the edge of the boreal forest, the massive belt of forest stretching across northern Canada, Europe, and Russia, where it transitions to Arctic tundra. This movement suggests a potential way to boost carbon sequestration in the area, said study lead author Kevin Dsouza, a postdoctoral researcher in Earth and environmental sciences at the University of Waterloo in Canada.

"What is the potential for reforestation in these regions, and how much carbon could they sequester?" he told Live Science.

In the new study, his team used satellite data to identify forest composition and empty spaces in the northern boreal forest, and ran simulations using models from the forestry industry that included fire probabilities, climate variables, seedling mortality and land type to estimate how much carbon the ecosystem could sequester over the next 75 years.

The simulations identified around 6.4 million hectares (15.8 million acres) of land suitable for reforestation — an area about twice the size of Vancouver Island — across Canada's north. Planting trees on this land would remove almost 4 gigatons of carbon from the atmosphere by 2100, about five times Canada's current annual emissions. But that 6.4 million hectares is a fairly conservative estimate of the available land, Dsouza said. Scaling it up to 32 million hectares (79 million acres) could sequester almost 20 gigatons.

The work was published Nov. 13, 2025, in the journal Communications Earth & Environment.

Canada did have an ambitious plan to plant 2 billion trees by 2031, but it was canceled last year. As of June 2025, 228 million trees had been planted, and the government plans to honor other agreements that should see 988 million trees planted across the country.

Dsouza said the 2 billion-tree plan ran into trouble due to complicated logistics and a lack of funding, rather than any problem with the science of reforestation. "It wasn't planned well, just trying to hit a number is not the right strategy," he said. "It needs to be more strategic, planting in the right places, with economic and community benefits so it is sustainable."

Focusing on northern areas could have the added benefit of helping to stabilize permafrost, which can release huge amounts of methane — a much more potent greenhouse gas than carbon dioxide — when it thaws, Dsouza added.

Longer term thinking needed

However, a separate team of experts disagrees with this solution and has instead proposed another way to use trees to reduce CO₂.

Ulf Büntgen ,professor of Environmental Systems Analysis at the University of Cambridge in the U.K. who was not involved in the research, told Live Science that while planting trees is good for removing carbon in the short term, few advocates consider the longer term problem of carbon storage.

"Planting trees is good but it's not solving anything, it's just buying time," he said. "While the tree is growing it helps, but eventually it will die and release the carbon again."

In a study published Jan. 3 in the journal NPJ Climate Action, Büntgen and his colleagues proposed a more long-term solution: cutting down trees in the boreal forest and sinking them deep in the Arctic Ocean. They suggest targeting large mature trees in specific plots of land in Canada, Russia and Alaska, which are most susceptible to fire and store carbon less efficiently than younger trees. The deep, cold and oxygen-poor water of the Arctic Ocean would preserve the trees, and the carbon they contain, for thousands of years, he said. The harvested areas could then be replanted with new trees to restart the carbon-capturing cycle.

The team suggested that managing just 1% of the boreal forest in this way would remove 1 gigaton of carbon dioxide from the atmosphere each year.

"There's already a lot of carbon in the timber that naturally finds its way to the ocean," he said. "We could accelerate this natural process."

Wildfires on Alaska's North Slope are more frequent and more severe now than they have been at any point over the past 3,000 years, research suggests.

The findings are based on satellite data and ancient charcoal fragments. The research team says the increase in blazes, driven by permafrost thaw and tundra "shrubification," constitutes a new wildfire regime that will likely intensify as global temperatures continue to rise.

Fires in northern Alaska "burn in summer, when the vegetation is snow-free and dry enough to ignite," study lead author Angelica Feurdean, a paleoecologist at Goethe University Frankfurt in Germany, told Live Science. In the past, this region was dominated by sedges and mosses, which provided little fuel for fires. But recently, there has been a shift toward woody shrubs, which are far more flammable and supply much more fodder for blazes, Feurdean said.

Researchers previously documented an increase in wildfires over recent decades on Alaska's North Slope and elsewhere in the Arctic, but the new study contextualizes these reports by examining wildfires over past millennia.

The research, published Nov. 10, 2025, in the journal Biogeosciences, reveals that the current peak in northern Alaskan fires started in the mid-20th century and hugely exceeds wildfire activity recorded as charcoal in local peatlands since about 1000 B.C. Global warming is behind the increase, the authors say, because rising temperatures create dry conditions on land as well as moisture in the atmosphere that boosts the risk of lightning, the main source of ignition in Alaska.

The soil samples in the study came from nine peatlands located between the Brooks Range and the Arctic Ocean. Many of these peatlands are covered in small shrubs and sphagnum moss (also known as peat moss), which only recently became widespread on Alaska's North Slope, where it replaced tussock-forming sedges such as Eriophorum vaginatum. Sphagnum moss can absorb moisture from the air, which is how it thrives despite drying conditions, Feurdean said. Sedges, on the other hand, need access to water in the soil to survive.

The samples were cores that measured about 1.6 feet (0.5 meters) long and encapsulated the past 3,000 years. The researchers analyzed the samples to reconstruct changes in vegetation, soil moisture and wildfire activity over time. Specifically, they inspected pollen and other plant remains; charcoal fragments; and tiny, single-celled organisms called testate amoebae, which are good indicators of water-table levels.

The researchers also analyzed satellite images of wildfires north of the Brooks Range between 1969 and 2023. When they combined these images with charcoal data to reconstruct the frequency and severity of fires, they found large discrepancies in the 2000s, when satellites captured huge fires but there was minimal charcoal evidence.

One explanation is that these fires were hotter than 930 degrees Fahrenheit (500 degrees Celsius) — the threshold above which charcoal turns to ash, Feurdean said. If that's the case, then the mismatch in the data over the past two decades suggests there has been an increase in extremely intense fires, she said.

Overall, the results showed a dramatic decline in soil moisture since about 1950 due to accelerating permafrost thaw, which causes surface water to sink into the ground. Plants that depend on shallow soil moisture, such as sedges and certain mosses, were replaced by shrubs — particularly shrubs in the heath family (Ericaceae) — and sphagnum moss, leading to an explosion in plant fuel for wildfires.

Combined with a rise in temperature and lightning strikes, these effects have culminated in the most severe wildfire activity in 3,000 years, Feurdean said.

Alaska's North Slope is likely a model for what is taking place across Arctic tundra ecosystems, and we can expect wildfires to worsen if warming continues, Feurdean added.

"If you have higher temperatures, you have higher shrub cover, more flammable biomass, and then more fires," she said. "The fires will continue to be more frequent and severe."

Editor's Note: This story was updated at 10:28 a.m. ET on Feb. 12 to clarify that only satellite data and charcoal fragments, and not other data sources, were used to look at past fire history.

Mass tree planting in China is turning one of the world's largest and driest deserts into a carbon sink, meaning it absorbs more carbon from the atmosphere than it emits, new research reveals.

The Taklamakan Desert (also spelled Taklimakan or Takla Makan) is slightly larger than Montana, stretching across about 130,000 square miles (337,000 square kilometers). It is encircled by high mountains, which block moist air from reaching the desert for most of the year, creating extremely arid conditions that are too harsh for most plants.

However, over the past few decades, China has sowed a forest around the Taklamakan's edges, and a new study suggests this approach is beginning to bear fruit.

"We found, for the first time, that human-led intervention can effectively enhance carbon sequestration in even the most extreme arid landscapes, demonstrating the potential to transform a desert into a carbon sink and halt desertification," study co-author Yuk Yung, a professor of planetary science at Caltech and a senior research scientist in NASA's Jet Propulsion Laboratory, told Live Science in an email.

Over 95% of the Taklamakan Desert is covered in shifting sand, meaning it has long been considered a "biological void," according to the study. The desert has been growing since the 1950s, when China underwent massive urbanization and farmland expansion. This conversion of natural land created the conditions for more sandstorms, which, in general, blow away soil and deposit sand instead, causing land degradation and desertification.

In 1978, China implemented the Three-North Shelterbelt Program, a huge ecological engineering project intended to slow desertification. Also called the "Great Green Wall," the project aimed to plant billions of trees around the margins of the Taklamakan and Gobi deserts by 2050. More than 66 billion trees have been planted in northern China to date, but experts debate whether the Great Green Wall has significantly reduced the frequency of sandstorms.

China finished encircling the Taklamakan Desert with vegetation in 2024, and researchers say the effort has stabilized sand dunes and grown forest cover in the country from 10% of its area in 1949 to more than 25% today.

Now, scientists have found that sprawling vegetation in the Taklamakan Desert's periphery is absorbing more carbon dioxide (CO₂) from the atmosphere than the desert is releasing, meaning the Taklamakan may be transforming into a stable carbon sink.

The researchers analyzed ground observations of different vegetation-cover types, as well as satellite data showing precipitation, vegetation cover, photosynthesis and CO₂ fluxes in the Taklamakan Desert over the past 25 years. They also used the National Oceanic and Atmospheric Administration's Carbon Tracker, which models CO₂ sources and sinks globally, to bolster their findings.

The results, published Jan. 19 in the journal PNAS, show a long-term trend of expanding vegetation and rising CO₂ uptake along the desert's edges that coincides both in time and space with the Great Green Wall.

Over the study period, precipitation during the Taklamakan Desert's wet season from July to September was 2.5 times higher than it was in the dry season, averaging about 0.6 inches (16 millimeters) per month. Precipitation enhanced vegetation cover, greenness and photosynthesis along the desert's margins, thereby lowering CO₂ levels over the desert from 416 parts per million in the dry season to 413 ppm in the wet season.

Previous research indicated that the Taklamakan Desert may be a carbon sink, but those studies focused on CO₂ that is absorbed by the desert's sand. They also suggested that sand is not a stable carbon sink under climate change, because rising temperatures can cause air in the sand to expand, which releases extra CO₂.

"Based on the results of this study, the Taklamakan Desert, although only around its rim, represents the first successful model demonstrating the possibility of transforming a desert into a carbon sink," Yung said.

The Great Green Wall's potential to slow desertification remains unclear, but its role as a carbon sink "may serve as a valuable model for other desert regions," he added.

An extra helping of nitrogen can double the growth of tropical trees in a recovering forest, vastly boosting the amount of carbon dioxide (CO₂) they can absorb for a decade, according to a new study.

Researchers found that adding a nitrogen fertilizer to the soil in the youngest forests — those that had been pastures less than a year ago — increased their tree biomass by 95% compared with a non-fertilized control group. Ten-year-old forests also bounced back with the nitrogen treatment, showing a 48% increase in growth compared with the control group.

"We all rely on tropical forests to stabilize our climate," study co-author and principal investigator Sarah Batterman, an associate professor at the University of Leeds and ecosystem ecologist at the Cary Institute of Ecosystem Studies, told Live Science. "They store about half of forest carbon and sequester about 20% of our carbon emissions. But there's huge uncertainty in whether tropical forests will continue to take up CO2 or will become a source of carbon into the atmosphere in the future. One of the key uncertainties is the role of nutrients in supporting more carbon sequestration and recovery from disturbance."

Researchers with the Smithsonian Tropical Research Institute (STRI) tracked the growth of trees and woody vine lianas across a four-year period, monitoring how fertilizers of nitrogen, phosphorus or a combination of both would impact growth. Working in plots around the Panama Canal watershed, they also tested responses across a gradient of forest types, including areas that had been cattle pastures less than a year prior, 10-year-old recovering forests, 30-year-old recovering forests and 600-year-old forests.

For three months each year, field teams fertilized the trees at regular intervals. "You're driving up and down these steep hills to get to the field site," Batterman said. "And it's super beautiful. You can see the Panama Canal in the distance, with the big ships driving through. And then you're driving through this landscape of pastures with cows and some forests in different stages of recovery."

After hikes ranging from five minutes to an hour and a half, the field teams would fertilize the trees and measure their trunks. "It's superhot and sweaty, lots of mosquitoes and insects," Batterman said.

From the diameter of the tree trunks, researchers can extrapolate the aboveground biomass of the trees and, importantly, their carbon storage.

The team's findings, published Jan. 13 in the journal Nature Communications, showed that nitrogen almost doubled growth in the areas that had been agricultural land until a year prior and boosted growth by almost 50% in forests that had been recovering for 10 years.

Older forests showed no response to the extra nitrogen, and no forests showed a response to the phosphorus fertilizer.

When trees are harvested from tropical rainforests, the soil below is also degraded, with nutrients like nitrogen and phosphorus being depleted. This degradation is still detectable decades after deforestation.

But rather than suggesting we physically fertilize vast tropical forests with nitrogen, the new findings can be used to plan forest recovery projects that prioritize tree species that can convert atmospheric nitrogen into a nutrient. This is known as "nitrogen fixing trees," study co-author Jefferson Hall, director of the Agua Salud project at STRI, which provided some of the forest plots where the experiment took place.

"It's not practical that people are going to go out and, you know, fertilize all the forests of the world to capture CO₂," Hall told Live Science. "The natural way of enhancing the nitrogen system would be to plant more nitrogen-fixing trees."

Richard Birdsey, a senior scientist at the Woodwell Climate Research Center who was not involved in the study, said the findings confirmed a long-standing observation about nutrients. "When I went to school, 50 years ago, the issue of nutrient depletion in tropical forests was known at that time. But no experiments like this had been done. It was simply some observations," he told Live Science.

Former tropical forests that had been removed, most often for agriculture, lack nutrients in the soil, and it often takes a long time for these nutrients to rebuild — even when the land is reforested. "The study, in a way, confirms these long-held beliefs about how tropical forests operate and what happens to them when they're harvested," Birdsey said.

Birdsey, who was with the U.S. Forest Service for over four decades, said recovering tropical forests are a vital global carbon sink, meaning they absorb more carbon than they release.

"They take up about 2.5 pentagrams of carbon per year," he said. "Globally, forests take up something like 3.5 pentagrams. So tropical forests, overall, are the biggest component of the carbon sink. And tropical regrowth forests, or regenerating forests, are the biggest part of the tropical forest sink."

Scientists have created a new tool to watch plants breathe in real time. The new tech could help identify the genetic traits that make crops more resilient to global climate change, the researchers say.

Humanity's food system depends on tiny pores on plants' leaves. These microscopic pores, called stomata (from the Greek word for mouth) regulate how much carbon dioxide a plant consumes and how much oxygen and water vapor it breathes out.

"It's very important for us to understand stomata better," study co-author Andrew Leakey, a plant biologist at the University of Illinois Urbana-Champaign, told Live Science. "I, and many other people, are looking to find ways to use either breeding or biotechnology to alter the way stomata are performing in order to produce better crops, in particular ones that need less water."

Specialized cells surround the pore openings, and they expand and contract to open and close the stomata. But scientists still don't know exactly how individual stomata regulate what the plant moves in and out.

"Despite the fact that we have studied stomata for a very, very long time, and we do know a great deal about them, we really struggle to connect understanding the amount of these oxygen, water and carbon going in and out of the stomata with how many stomata there are, how big they are, and how they open," Leakey said.

To understand this process better, researchers developed the Stomata In-Sight tool, which they described in a study published Nov. 17, 2025 in the journal Plant Physiology. The Stomata In-Sight instrument combines a microscope, a system to measure the stomatal gas flux, and machine-learning image analysis. "It measures the collective activity of thousands upon thousands of stomata in terms of these carbon dioxide and water fluxes," Leakey said.

To use Stomata In-Sight, small pieces of leaf are placed in a climate-controlled chamber about the size of a human palm, which is connected to a gas exchange system, Leakey explained. Researchers can change the conditions inside the chamber to see how the stomata respond to variations in temperature, water availability and other parameters. The microscope sits outside the chamber, looking in, while the machine-learning analysis identifies stomata from the microscope's images, speeding up analysis.

It has taken the team several years to develop the new tool. A major issue was that tiny vibrations — such as the fan in a gas-exchange system — can lead to blurry images. "This actually took us about five years, and we had probably three prototypes that failed when we got to the final solution," Leakey said.

The team has already used the system to look at the stomata of maize (Zea mays) and other crops. It also used the insights about stomata to engineer sorghum (Sorghum bicolor, a type of plant cultivated for grain) to use less water. They identified the genes responsible for the density of stomata on sorghum leaves and engineered plants with more spread-out stomata.

The University of Illinois Urbana-Champaign has patented the technology, and while it is not commercially available, Leakey hopes that there may be companies interested in producing the instrument for other research groups.

Not all scientists are convinced, however. Alistair Hetherington, an emeritus professor of botany at the University of Bristol in the U.K., doubts that the new tool will revolutionize the study of stomata.

"We have been able to use conventional microscopy to measure changes in stomatal aperture for well over hundred years, confocal microscopy for probably 25 years, and the so-called gas exchange techniques for 50 years," he told Live Science. The new study puts the techniques together, but researchers are likely to stick to "tried and tested existing techniques that deliver," Hetherington added.

Nevertheless, Leakey is looking at improving the tool to broaden its usefulness. The main challenge at the moment is that watching the stomata "breathe" is very time consuming. "When you're looking through the microscope, you see on average two to three stomata in the little piece of leaf you're looking at," he explained. "But you actually need to measure 40 or 50 stomata in order to account for the variation." This has to be done manually.

Also, it can take a few minutes for stomata to respond to changing conditions. This means that scientists have to wait for the stomata to finish opening or closing before they take another image.

"It's quite labour intensive, but it's possible we could use robotics and artificial intelligence to turn it into a production-line process," he said. "There's a lot of excitement in the scientific community about how we can accelerate biological research using those sorts of tools."

As its name suggests, the Avenue of the Baobabs is a road in Madagascar that’s lined with towering baobab trees. The trees are the remnants of a tropical forest that once sprawled across the island, and in the modern era they are listed as a natural monument by Madagascar's government.

The Avenue of the Baobabs is made up of endangered Grandidier's baobabs (Adansonia grandidieri) — one of six endemic baobab species in Madagascar. The trunks of Grandidier's baobabs typically grow around 80 feet (24 meters) tall and 10 feet (3 m) wide, but the biggest specimen ever recorded was a 98-foot (30 m) giant with a diameter of 36 feet (11 m), according to the plant sciences faculty at the University of California, Davis.

Grandidier's baobabs have such huge trunks because they store water. However, water doesn't gush out if you drill a hole into a baobab; rather, the trees store water in their cells, in order to grow new leaves and maintain their structure, according to the Baobab Foundation.

The Avenue of the Baobabs is an unpaved road between Morondava and Belo Tsiribihina, two towns close to Madagascar's west coast. About 20 to 25 Grandidier's baobabs line a short stretch of the road, but 25 more trees of the same species grow scattered among rice paddies and meadows just a short distance away — and there are hundreds of baobabs in the surrounding landscape.

Baobabs evolved in Madagascar between 41 million and 21 million years ago, a 2024 study found. Most of the baobab species that exist today remain in Madagascar, but two species — A. digitata and A. gregorii — are found in continental Africa and Australia, respectively. It's unclear how the baobabs got there, but researchers have proposed that the fruits may have crossed the oceans on currents or been transported by humans.

In Madagascar, baobabs are called "renala" or "reniala," meaning "mother of the forest." The name points to evidence suggesting that the baobabs that give their name to the Avenue of the Baobabs only recently became isolated trees; thousands of years ago, they stood in a dense tropical forest.

Today, baobabs in Madagascar face extinction threats from illegal logging, fires and climate change. Nevertheless, the trees play a central role in Malagasy culture, featuring in local legends such as that of the "Baobab Amoureux," or "Loving Baobabs" — two intertwined trees that are said to embody a pair of star-crossed young lovers who were forced to marry other people.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

When drought hits, tropical forests in Panama have a "rescue strategy" to adapt to the lack of water by sending their roots deeper underground, a new study has found. But scientists warn this may not be enough to save them from the ravages of climate change.

Tropical forests are home to more than half of the world's terrestrial biodiversity and store large quantities of global carbon. A lot of this carbon is held in their roots below ground. However, climate change is pushing up temperatures in these forests and is expected to bring extreme droughts.

In a new study, published Nov. 21 in the journal New Phytologist, scientists investigated what happens to the roots of trees in tropical forests when they are deprived of water for a long time.

The results are part of the Panama Rainforest Changes with Experimental Drying (PARCHED) experiment, in which scientists set up 32 plots in four different areas in Panama's tropical forests. Each of the four forests has distinct characteristics, such as tree species, soil nutrient availability and rainfall.

The scientists erected clear roof structures above the plots that excluded 50% to 70% of the rainfall from reaching the forest floor. The structures "look like partial greenhouse roofs," study co-author Daniela Cusack, an ecosystem ecologist at Colorado State University, told Live Science. She has been leading the PARCHED experiment since 2015. The researchers also dug trenches around the plots, which they lined with thick plastic so that the roots could not access water from outside the plots.

The researchers used three methods to find out what was happening with the trees' roots.

They sampled soil cores four times a year for five years. The cores extended about 8 inches (20 centimetres) below the surface. The researchers also had root traps, which are mesh columns filled with soil. Every three months, they checked how many roots had grown into these columns.

The third method involved using small cameras to watch how the roots grew. When the PARCHED experiment was set up, the researchers sank acrylic tubes about 4 feet (1.2 meters) into the ground. These tubes have gaps at regular intervals with cameras looking into the soil.

All four forests, despite being different from each other, showed similar responses to a slowly drying environment.

Chronic drying significantly reduced the quantity of fine surface roots, reducing water and nutrient availability, but the trees had a number of strategies to survive a chronic drought.

"The trees compensated for the surface-root dieoff by sending fine roots down deep into the soil, presumably for moisture acquisition," Cusack said.

"It's not enough root growth to compensate for the carbon or biomass loss," she said. It's more like a "rescue strategy for trees to maintain their hydraulics and physiological function."

At the same time, surface roots were more likely to be colonized by arbuscular mycorrhizal fungi. This type of fungi forms a symbiotic relationship with plants and increases the availability of water and nutrients.

The remaining surface roots appear to attract more of these fungi to improve their access to nutrients, Cusack said.

Daniela Yaffar, who was not involved in this research but studies roots in tropical forests at the Oak Ridge National Laboratory in the U.S., welcomed the study but said that more research was needed to understand how roots behaved in other tropical forests.

"While some species have long been adapted to drier environments, these adaptations typically evolve over extended periods," she told Live Science. "The emerging challenge is that tropical forests, especially in regions unaccustomed to such dry conditions, may experience significant shifts and not enough time to adapt."

Species that are less able to adapt to more extreme droughts may decline or disappear from the ecosystem, she said.

Cusack warned that the root adaptation was not a bulwark against climate change. "Our five-year study is pretty short in terms of the lives of tropical forests," she said. "We don't know how long the forest can sustain these adaptations."

Lead author Amanda Cordeiro, a researcher at the University of Minnesota, who was a PhD candidate at Colorado State University during the study, told Live Science the next steps will be to assess the long-term consequences of the root changes, and how it impacts the overall ecosystem in terms of carbon storage and plant fitness. "For example, it is currently unclear whether increased deeper root production can help tropical forests withstand ongoing chronic drying beyond a few years," she said.

China's "Great Green Wall" is a huge ecological engineering project to slow the expansion of the Gobi and Taklamakan deserts in the country's north.

Since 1978, China has planted more than 66 billion trees along its borders with Mongolia, Kazakhstan and Kyrgyzstan — and Chinese authorities plan to plant 34 billion more over the next 25 years. If they succeed, the Great Green Wall will increase Earth's forest cover by 10% since the late 1970s.

The Great Green Wall, formally known as the Three-North Shelter Forest Program, is designed to slow soil erosion and sand deposition that has been increasing since the 1950s due to huge urbanization and farmland expansion. These changes exacerbated the region's already dry conditions, which in turn created the conditions for more sandstorms. Sandstorms blow away the top layer of soil and deposit sand, degrading the land and increasing particulate matter pollution in cities.

Northern China was dry before the urbanization boom of the 1950s, because the Himalayas create a rain shadow over the country's border with Mongolia that limits precipitation in the region. This is why the Gobi and Taklamakan deserts are so enormous; combined, they cover 618,000 square miles (1.6 million square kilometers), which is slightly smaller than Alaska, according to the Royal Geographical Society.

Despite China's efforts over the past five decades, the Gobi and Taklamakan are still expanding. The Gobi Desert, for instance, swallows around 1,400 square miles (3,600 square km) of China's grassland every year. Desertification is ruining ecosystems and agricultural land, but it's also making pollution in cities like Beijing worse, according to the Royal Geographical Society.

Last year, government representatives announced China had finished encircling the Taklamakan with vegetation, which has helped stabilize sand dunes and grow forest cover from about 10% of China's area in 1949 to more than 25% today. Tree planting will continue around the Taklamakan to maintain and enlarge the forest, the representatives said.

If everything goes to plan, the Great Green Wall will be 2,800 miles (4,500 kilometers) long by 2050. The "wall" is the world's largest seeded forest — but it's still unclear just how effective it is at slowing desertification.

While some studies suggest the Great Green Wall has reduced the frequency of sandstorms, others argue this decrease is mostly due to climatic factors.

Critics say the survival rate of planted trees and shrubs is too low to show robust results, possibly because huge swathes of the wall encompass only one or two tree species — mostly poplar and willow, according to the Royal Geographical Society — making the wall susceptible to disease. For example, in 2000, 1 billion poplar trees were lost to a single pathogen in the Ningxia province.

Tree mortality is also high because China is planting trees in places that don't have enough water to grow them. Without constant human intervention, many of the trees don't survive.

"People crowded into the natural sand dunes and the Gobi to plant trees, which have caused a rapid decrease in soil moisture and the groundwater table," Xian Xue, a leading expert on erosion-driven desertification at the Chinese Academy of Sciences, told National Geographic in 2017. "Actually, it will cause desertification [in some regions]."

Because it is a monoculture, the Great Green Wall also doesn't promote biodiversity in the same way that a more diverse mix of indigenous plants would. Nevertheless, the program inspired Africa's Great Green Wall, which will be a 5,000-mile-long (8,000 km) tree belt across the continent to slow land degradation and desertification.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth

China's efforts to slow land degradation and climate change by planting trees and restoring grasslands have shifted water around the country in huge, unforeseen ways, new research shows.

Between 2001 and 2020, changes in vegetation cover reduced the amount of fresh water available for humans and ecosystems in the eastern monsoon region and northwestern arid region, which together make up 74% of China's land area, according to a study published Oct. 4 in the journal Earth's Future. Over the same period, water availability increased in China's Tibetan Plateau region, which makes up the remaining land area, scientists found.

"We find that land cover changes redistribute water," study co-author Arie Staal, an assistant professor of ecosystem resilience at Utrecht University in the Netherlands, told Live Science in an email. "China has done massive-scale regreening over the past decades. They have actively restored thriving ecosystems, specifically in the Loess Plateau. This has also reactivated the water cycle."

Three main processes move water between Earth's continents and the atmosphere: evaporation and transpiration carry water up, while precipitation drops it back down. Evaporation removes water from surfaces and soils, and transpiration removes water that plants have absorbed from the soil. Together, these processes are called evapotranspiration, and this fluctuates with plant cover, water availability and the amount of solar energy that reaches the land, Staal said.

"Both grassland and forests generally tend to increase evapotranspiration," he said. "This is especially strong in forests, as trees can have deep roots that access water in dry moments."

China's biggest tree-planting effort is the Great Green Wall in the country's arid and semi-arid north. Started in 1978, the Great Green Wall was created to slow the expansion of deserts. Over the last five decades, it has helped grow forest cover from about 10% of China's area in 1949 to more than 25% today — an area equivalent to the size of Algeria. Last year, government representatives announced the country had finished encircling its biggest desert with vegetation, but that it will continue planting trees to keep desertification in check.

Other large regreening projects in China include the Grain for Green Program and the Natural Forest Protection Program, which both started in 1999. The Grain for Green Program incentivizes farmers to convert farmland into forest and grassland, while the Natural Forest Protection Program bans logging in primary forests and promotes afforestation.

Collectively, China's ecosystem restoration initiatives account for 25% of the global net increase in leaf area between 2000 and 2017.

But regreening has dramatically changed China's water cycle, boosting both evapotranspiration and precipitation. To investigate these impacts, the researchers used high-resolution evapotranspiration, precipitation and land-use change data from various sources, as well as an atmospheric moisture tracking model.

The results showed that evapotranspiration increased more overall than precipitation did, meaning some water was lost to the atmosphere, Staal said. However, the trend wasn't consistent across China, because winds can transport water up to 4,350 miles (7,000 kilometers) away from its source — meaning evapotranspiration in one place often affects precipitation in another.

The researchers found that forest expansion in China's eastern monsoon region and grassland restoration in the rest of the country increased evapotranspiration, but precipitation only increased in the Tibetan Plateau region, so the other regions experienced a decline in water availability.

"Even though the water cycle is more active, at local scales more water is lost than before," Staal said.

This has important implications for water management, because China's water is already unevenly distributed. The north has about 20% of the country's water but is home to 46% of the population and 60% of the arable land, according to the study. The Chinese government is trying to address this; however, the measures will likely fail if water redistribution due to regreening isn't taken into account, Staal and his colleagues argued.

Ecosystem restoration and afforestation in other countries could be affecting water cycles there, too. "From a water resources point of view, we need to see case-by-case whether certain land cover changes are beneficial or not," Staal said. "It depends among other things on how much and where the water that goes into the atmosphere comes down again as precipitation."

Scientists have finally discovered how a weird desert plant can thrive in one of the hottest places on Earth. Turns out, the plucky plant rearranges its insides when the temperature goes up.

California's Death Valley frequently experiences extreme conditions. Summer temperatures often soar above 120 degrees Fahrenheit (49 degrees Celsius) in the shade. Most plants wither in the face of such heat, but one plant, Tidestromia oblongifolia, thrives.

Now, researchers have found that these gray-green flowering shrubs grow smaller leaves and rearrange their insides to flourish in super-hot conditions. They also found that the shrub has the best photosynthetic heat tolerance — the ability to photosynthesize at high temperatures of any known plant.

The research was published Nov. 17 in the journal Current Biology.

Climate change is driving up global temperatures and increasing the frequency of heat waves. The heat is already reducing crop yields for staple foods like wheat and maize, and scientists and officials are worried about what this means for food security as temperatures continue to rise.

Heat-loving plants, such as T. oblongifolia, could hold the secrets to help other plants survive the heat and keep food on people's plates. "Understanding their adaptations could help researchers design crops, environments, and management strategies to improve growth under increasingly frequent and prolonged high temperatures," study co-author Seung Rhee, a plant biologist and director of the Michigan State University’s Plant Resilience Institute, told Live Science.

Scientists have known for decades that there is something special about T. oblongifolia. At higher temperatures, most other plants' rate of photosynthesis declines. But in 1972, researchers showed that T. oblongifolia's photosynthesis peaked at 117 F (47 °C).To find out how the hardy survivor can continue to photosynthesize and flourish while other plants wither, the researchers behind the new study collected seeds from Death Valley and grew the plants in growth containers. When the plants were eight weeks old, the scientists subjected them to Death Valley conditions for a month. They then observed the plants' responses, such as how much carbon dioxide they absorbed.

Within two days, T. oblongifolia had intensified its rate of photosynthesis. After 10 days, it had tripled its biomass in a profusion of leaves that were smaller than the ones it produces at lower temperatures.

But the really surprising change happened within the plant. The scientists found that it developed more mitochondria, which are the powerhouses — or batteries — within the cell. These mitochondria were also more mobile and able to move closer to the sites of photosynthesis, which takes place inside special organelles called chloroplasts.

"This plant is moving the mitochondria around, reducing their volume, but increasing the density so that there are concentrated energy centres around the chloroplasts," Andy Leigh, a plant ecologist at the University of Technology Sydney in Australia who specializes in heat-loving plants and was not involved in the research, told Live Science.

In response to the brutal Death Valley temperatures, the plant's chloroplasts also changed from ovals into a cup-like shape — something that had been previously seen in algae but not in plants that have many chloroplasts in the same cell. The researchers are not sure how the cup shape promotes photosynthesis and survival.

T. oblongifolia also rewires its transcriptome, which is a script of all the RNA messages that the cell produces at a given time and indicates which genes are being used or expressed. Some of the active genes focused on heat response and the plant's repair system.

Rhee said the team's next step would be to identify and characterize candidate genes to further narrow down how the plant survives. These could then enable researchers to find new ways to help other plants survive rising temperatures.

"The mechanisms that lead to temperature sensitivity are well known, but strategies to overcome these inefficiencies are still being developed," Carl Bernacchi, a crop researcher at the University of Illinois Urbana-Champaign who was not involved in the research, told Live Science. The new insights provide "a roadmap for potentially overcoming these challenges," he said.

T. oblongifolia's strategies to survive and flourish at high temperatures could "help increase crop resilience not only for the future, but also for parts of the world that are presently food insecure," he added.

Leigh was excited by the new research. T. oblongifolia "could physically reconfigure its photosynthetic machinery when the chips were down, and to maintain photosynthetic function when it was stressful. That's really cool," she said.

Leigh, who studies heat-loving plants in Australia's scorching deserts, said there is a lot scientists still don't know about organisms that survive in extreme environments.

"This particular species looks like a weed — a really freaky thing that you could just overlook," she said. "There are really weird plants out there doing weird stuff that could be the key to improving our crops."

Every fall, pumpkin growers haul their record-breaking giants onto scales, with some pumpkins weighing more than 2,700 pounds (1,225 kilograms). Yet the world's largest apple barely reaches 4 pounds (1.8 kg), and the heaviest blueberry ever grown weighs less than an ounce (28 grams). So what allows pumpkins to grow to such staggering sizes while other fruits (yes, pumpkins are fruits and even a type of berry) remain comparatively tiny?

Giant pumpkins are a specific variety of Cucurbita maxima that's been bred to grow huge — most often Mammoth and Atlantic Giant varieties. A basic reason they can grow so large is that they're indeterminate plants, Vikram Baliga, an assistant professor of practice of horticulture at Texas Tech University, told Live Science. Whereas determinate plants reach a set size and then stop, indeterminate plants grow indefinitely.

"So you'll see these big, sprawling pumpkin plants that take over your entire yard, and sometimes it's just one plant," Baliga said.

Determinate plants tend to produce all their fruit at once, which has benefits for harvesting but limits how large they can grow.

"Some plants, when they grow an organ — whether it's a leaf, whether it's a fruit, whether it's a flower — they have a program that limits how big that particular thing they grow will be," Jessica Savage, an associate professor in the Swenson College of Science and Engineering at the University of Minnesota Duluth, told Live Science. "Other species don't have that kind of limit. … For some reason, the pumpkins don't seem to have a really strong one that limits their size, and so that allows us to breed for bigger ones."

With nothing to limit their growth potential, pumpkin plants can continuously add more leaves to generate energy for their fruit.

"With an indeterminate plant, its goal is to produce as much biomass as it can, as quickly as possible, so your pumpkin is going to put on leaves and stems and all kinds of stuff," Baliga said. "Then, if it needs to produce more energy, it just grows more leaves. It doesn't have that genetic choke point."

How to grow a giant pumpkin

Growers take advantage of this by removing all but one pumpkin from the vine.

"If you've got this plant that's able to bank all these resources and you pull eight pumpkins off the plant and just leave one, it's like 'Great, I'm just going to divert it all into this one fruit. This is my only chance to carry on my genetics,'" Baliga explained.

Technically, this trick also works with other fruits. Removing all but one peach from a tree, for example, can produce a larger peach. But that's where the laws of physics come into play.

For one thing, pumpkins grow on the ground, so they're less subject to the pull of gravity; a giant peach would not be able to grow as large as a pumpkin because it would fall off the tree long before it reached that weight.

In addition, a pumpkin's hard rind allows it to grow larger than a fruit with soft skin. "You wouldn't be able to get a really big fruit on something that's really soft because it would start to weigh itself down and it would start to break," Savage said.

However, a rind that's too stiff won't allow the pumpkin to grow to a massive size. "The people who grow pumpkins work to get that sweet spot — you don't want them so stiff that they can't expand. … If the skin splits, it's not competitive. So you have to have the skin soft enough, but it has to be strong enough that it can support its own weight."

When they're young, giant pumpkins have soft, thin skin that allows them to grow rapidly. As they mature, the skin hardens, Savage said. Growers protect pumpkins from the sun by covering them with a tarp to keep them in that soft, rapid growth phase as long as possible.

At peak growth, giant pumpkins can pack on 44 pounds (20 kg) a day — and all that mass has to move through the fruit's vascular system, which Savage said is "superpowered." Savage and her team have found that, compared with other pumpkin varieties, giant pumpkins have more phloem, which is the part of the vascular system that transports sugar.

"I often think about it like a highway," she said. "You can move the same amount on a small highway, but you're limited by how fast it happens. If you want to move a lot more resources more rapidly … you have to have more roads."

Giant pumpkins also have a lot of time to grow. "A pumpkin stays on the vine for months … they're like a five- to six-month crop, 180 days in some cases," Baliga said. "Whereas your apples, your peaches, your pears, a lot of your blueberries, they tend to be much quicker from flower to harvest."

But an equally important reason giant pumpkins get so big is that we made them that way. "They've been selectively bred for a really long time, just for size, which is different than a lot of other foods where we're also selecting them for taste," Savage said.

Pumpkins are a symbol of fall and central to Halloween and Thanksgiving traditions, so they hold a more prominent place in our culture than other fruits with similar growth potential, like cucumbers.

For her part, Savage thinks pumpkins will keep getting bigger. "There probably is eventually a limit, but I think we'll keep finding ways to push it," she said.

Fruits and vegetables quiz: Do you know where pumpkins, blueberries and broccoli come from?

If you walk into a grocery store, you'll likely see piles of fruits and vegetables waiting to be purchased. But these foods didn't always look this way; many were domesticated — that is, selectively grown for certain characteristics — over hundreds if not thousands of years to be large and extra tasty.

These eatables each arose in a unique environment. So, do you know where apples and pumpkins emerged? What about potatoes, cherries and lemons? Aromatic treats made from beans, like chocolate and coffee, were also cultivated by humans. Take our quiz to see if you can nail down the origin of 15 fruits, vegetables and beans.

Remember to log in to put your name on the leaderboard; hints are available if you click the yellow button!

More science quizzes

—Animal quiz: Test yourself on these fun animal trivia questions

—What's inside Earth quiz: Test your knowledge of our planet's hidden layers

—US volcano quiz: How many can you name in 10 minutes?

Scientists have uncovered a "hidden order" in drylands across the planet, where plants follow disordered hyperuniformity — a layout that looks random and disorganized up close but adheres to a clear pattern when viewed from farther away.

The findings explain phenomena like "tiger bush" in West Africa, where bands of plants look like tiger stripes from above, or "fairy circles" in Namibia that look like spots from far away but are actually clumps of plants. These plants are self-organized in a way that helps them cope with drought and function in extreme conditions.

"It was a genuine surprise," study co-author Quan-Xing Liu, a mathematician at the Shanghai Jiao Tong University in China, told Live Science in an email. "We expected to find either a completely random distribution or a regular, clumped pattern… instead, we uncovered a perfect disordered hyperuniform pattern — a form of hidden order no one had recognized before in plant communities."

In the new study, published Oct. 7 in the journal PNAS, researchers looked at satellite images of more than 400 arid areas around the globe and mathematically analyzed the spatial patterns of the plants in those landscapes. They found that though the plants' distribution might look disordered on the ground, from an aerial view 10% of drylands follow a hyperuniform pattern — showing the phenomenon is not just a rarity but a widespread feature of many dry ecosystems.

The pattern is likely the result of intense competition for scarce resources, Liu said. Arranging themselves in this hyperuniform way can help plants survive with limited water. If they are too close to each other the individual plants would compete for water, but being too far apart would leave gaps for other types of plants to invade, so this pattern enables just the right balance for a dry ecosystem.

Over time, the vegetation slowly organizes into a disordered hyperuniform state shaped by this balance. "It's a brilliant, emergent strategy to maximize resource usage and minimize competitive conflict for the whole community," Liu said.

Related: 'This needs to happen fast': Scientists race to cryopreserve a critically endangered tree before it goes extinct

Chemists first defined disordered hyperuniformity in the 2000s. They observed atoms not arranged in a crystal solid pattern (a highly organized grid) or a liquid or gas pattern (much less organized and random). Instead they were arranged in a disordered hyperuniform way, giving it the benefits of an organized system but with more flexibility.

Scientists have identified this pattern more and more throughout the natural world, from the atomic scale to entire galaxies. The rods and cones in birds' eyes are organized in a hyperuniform way, and some algae swim in hyperuniform patterns.

It has also previously been observed in plants — including in leaf vein networks, Jiao's work shows.

"We can learn a lot from these biological systems that are optimized by many years of evolution and natural selection," Yang Jiao, an engineer at Arizona State University who was not involved with the research, told Live Science. "I'm not surprised by the results. Similarly to what we show with the leaf patterns, if the environment is harsh, the system adapts more towards optimal hyperuniform states," he added.

But this optimal balance makes it harder for the ecosystem to recover from human disturbance, like climate change, invasive species, or infrastructure.

"Roads and ditches act as scars interrupting water flow," Liu said. "Once those gradients are disturbed, the 'hidden order' collapses. In this way, the loss of hyperuniformity can serve as a sensitive early warning sign — a signal that the ecosystem is becoming stressed and is losing the natural resilience that this hidden order provides."

Liu's team now plans to search for hidden orders in other extreme ecosystems, including those beyond Earth. Analyzing NASA's Curiosity rover images of a crater on Mars, they found that pebble clusters on sand show the same disordered hyperuniformity as dryland plants on Earth, driven not by biology but by physical forces like wind, sand movement, and gravity.

"That the same geometric principle appears in such different systems suggests that disordered hyperuniformity is a universal solution to the challenge of packing and efficiency under constraints," Liu said, "whether the 'particles' are plants, pebbles, or cells."

When Burl Ives sang "Silver and gold decorations, on every Christmas tree" in "Rudolph the Red-nosed Reindeer," he surely didn't know that Christmas trees actually have gold inside their needles — but that's exactly what new research has found.

A study published Aug. 28 in the journal Environmental Microbiome reports that Norway spruce trees (Picea abies) concentrate gold nanoparticles with the help of their resident bacteria.

"Our results suggest that bacteria and other microbes living inside plants may influence the accumulation of gold in trees," lead study author Kaisa Lehosmaa, an ecologist at the University of Oulu in Finland, said in a statement.

These resident bacteria are known as endophytes — symbiotic microorganisms that facilitate hormone production and nutrient absorption, among other functions. In the spruce trees, these bacteria segregate soluble gold particles that the trees take up in water through their roots.

The process is a form of biomineralization, in which living things control the formation of minerals in their tissues through a wide array of processes. In this case, the endophytes likely concentrated the particles to reduce their toxicity.

Striking gold

For the study, the researchers investigated spruce trees near the Kittilä mine in northern Finland — the largest producer of gold in Europe. The researchers examined 138 needle samples from 23 spruce trees. Needles from four of the trees contained gold nanoparticles.

The nanoparticles were surrounded by biofilms created by bacterial genera such as P3OB-42, Cutibacterium and Corynebacterium. These films are polysaccharide (complex sugars) and protein compounds secreted by the bacteria that allow them to persist within the plant tissues.

The close association between the nanoparticles and bacterial biofilms indicated that the bacteria were likely responsible for isolating the mineral. The diversity of bacterial species was lower in needles that contained gold; other studies of plants with high concentrations of metals in their tissues have also found decreased microbial biodiversity.

No one will be making a fortune by cutting down spruces to distill the tiny amounts of gold in their needles — the particles measure a mere millionth of a millimeter. However, the trees' uptake of the valuable mineral by the trees may be a useful indicator of gold deposits under the surface.

"Screening for such bacteria in plant leaves may facilitate gold exploration," Lehosmaa said.

If you love figs, you may have heard some unsettling lore about them: that every fig hides a wasp, because these insects need to crawl inside and die in order for the fruit to grow. But are there really wasps in the figs we eat, or is this just a myth?

The answer is somewhere in between. Wasps do play an essential role in the life cycle of many types of fig trees, but most figs from the supermarket are likely bug-free.

Fig wasps are a group of hundreds of species of small insects that spend much of their life inside figs. They're about the size of a fruit fly, and they're not the same type of wasps that sting humans. Figs and fig wasps have evolved alongside each other for millions of years, leading to a special relationship called mutualism, or a link between two species that benefits both of them.

"Fig trees and fig wasps are a great example of a mutualism," Charlotte Jandér, a plant ecology and evolution researcher at Uppsala University in Sweden, told Live Science in an email. "Other examples of mutualisms include trees and the mycorrhizal fungi that help the trees take up nutrients, animals and their gut microbes, and flowering plants and pollinators in general."

In the case of figs and fig wasps, the fruit gets pollinated and the wasp is able to reproduce, leading to a mutualism. But this relationship is rather complex.

What we think of as the fig "fruit" is actually a hollow structure called a syconium filled with tiny flowers. Generally, when a female fig wasp crawls inside a synconium from a female fig tree, she spreads pollen, which the plant needs in order to produce seeds and ripen. The hole that the wasp crawls in is very small, and she may lose her wings and antenna in the process and can even die inside the fig.

So, it's possible that some types of figs may have dead fig wasps inside them.

But that doesn't necessarily mean the figs we eat have wasps inside. Not all types of figs require pollination in order to ripen. Humans eat the fig species Ficus carica, which has several cultivars that are parthenocarpic, meaning they can produce ripe fruit without pollination — and therefore, without fig wasps.

"Most figs we eat in the US have no wasps inside them," Carlos Machado, a biology professor at the University of Maryland, told Live Science in an email.

Mission figs and Brown Turkey figs are two commonly-sold fig cultivars that don't require wasp pollination to ripen and produce seeds, Jandér said. This doesn't apply to all figs that humans eat, though; Smyrna figs, Calimyrna figs, and wild figs around the Mediterranean all rely on wasps for pollination.

"Most wild figs do require pollination to produce ripe fruit," Machado explained. That means these types of figs could have a tiny wasp inside them — but it's still not a guarantee.

Related: How do plants with seedless fruit reproduce?

Just because a wasp was once in the fig, doesn't mean it's still in there by the time the fig is eaten. The synconia of Ficus carcia have a large enough opening that the fig wasp is sometimes able to leave the structure after entering. If the wasp does die inside, her body generally gets squished and decomposes from the process of the fig maturing, Jandér said.

"Even if there were remnants of the original pollinator there you probably would not see them," Jandér explained. Any crunchy texture is more likely from the plant's seeds, not wasp remains.

The fig wasp life cycle

Although wasps sometimes die inside figs, these fruits are actually an essential part of their reproduction cycle. Just as most types of figs need wasp pollination to make new fruit, fig wasps couldn't reproduce without the help of fig trees.

When a female wasp crawls into a fig syconium from a female tree — the type of figs we eat — she only pollinates it, because the flowers inside are too long for her to lay her eggs on. But if she ventures into a synconium from a male tree — which are called caprifigs and generally not eaten by humans — she'll start to lay her eggs.

There, the eggs hatch and develop from larvae into young wasps, which mate while still inside the fruit. Generally, the male wasps die inside the caprifig after mating, though they do help chew a tunnel that allows the female wasps to escape, sometimes even offering themselves as bait for the predatory ants that may be waiting outside. Eventually, the fertilized female wasps burst out in search of a new fig to lay their eggs in, carrying pollen from the old caprifig with them.

There are over 850 species of fig trees, and each one can only be pollinated by a specific species of fig wasp, Jandér said. The relationship between these plants and animals evolved millions of years ago, and both Machado and Jandér pointed to its importance. As a keystone species — an organism that many other plants or animals in the ecosystem rely on to survive — fig trees and their relationship with wasps continue to be of great interest to researchers.

"There are other plant-pollinator mutualisms in nature, but the fig-fig wasp mutualism is possibly the most diverse and most consequential of all," Machado said.

​​For something curative and healing, most medicines have a surprisingly noxious taste. From bitter-tasting syrups to the persistent metallic aftertaste of certain tablets, why do many of our best treatments taste so bad — and how much does this actually matter?

The majority of modern drugs were developed from or inspired by compounds found in nature, particularly in static species such as plants and marine invertebrates like sponges and corals.

"They cannot move. They cannot escape. So the only tool that they have to defend themselves from predators is to produce chemicals and they are usually compounds that are, to some extent, toxic for humans or other animals,' Orazio Taglialatela Scafati, a pharmaceutical biologist at the University of Naples Federico II in Italy, told Live Science.

Over millions of years, these plants and animals evolved to produce compounds which interact with different receptors in their predator species, whether it's heart-stopping cardiac glycosides in foxgloves, hallucinogenic alkaloids in belladonna, or toxic taxane compounds in yew berries.

In response, humans (and many other animals, too) evolved taste receptors to detect these harmful compounds, with the bitter taste serving as a clear signal to avoid those potential foods. The bitter taste is therefore a warning sign that a particular chemical is likely to change the normal chemistry of the body.

Fast forward a few tens of thousands of years and modern science began helping us understand specifically how these compounds interact with our bodies, enabling us to harness their potent physiological effects in safe and effective medicines. Relatively few medications use these compounds exactly as they are produced by the organism, rare examples being antibiotics such as penicillin and painkillers like morphine. The majority instead draw inspiration from the chemical structure of the natural products, mimicking their biological activity with a few targeted improvements.

"A drug must have several features: it must have a good way of administration, it must be absorbed, must reach the target, and must be active," Taglialatela Scafati said. "So sometimes it's necessary to modify the structure of the drug in order to achieve this."

However, said Bahijja Raimi-Abraham, a pharmaceutical scientist and practicing pharmacist at King's College London, when thinking about medicines it's important to draw a distinction between the active drug compound and the dosage form which the patient actually takes.

In the medication the patient receives, the active ingredient is combined with biologically inactive components known as excipients, which both regulate drug properties like absorption and stability, and enable the medication to be processed into syrups, tablets and capsules which are easy to administer.

Theoretically, then, adding flavoring excipients should help to tackle the unpleasant taste of the active ingredient in tablets and syrups. But how patients perceive medications is in fact much more complex than just the flavor, Raimi-Abraham told Live Science. "People focus a lot on the taste but we should actually be focused on palatability," she explained. "We're not just thinking about taste, we're thinking about smell, we're thinking about aftertaste, texture, appearance. These factors determine if somebody is going to accept a medicine."

This is a particularly important consideration when working with pediatric and geriatric patients — if a medication is not palatable, there's a real risk that children and elderly patients will refuse (or struggle) to take the required dose. Not only does this potentially endanger the health of more vulnerable patients, but failing to complete a prescribed course of medication can also contribute to the more widespread phenomenon of drug resistance, especially with regard to antibiotics.

Striking a balance between the different aspects of palatability is consequently extremely important but incredibly difficult. Improving one factor may often adversely affect another and part of the challenge here is the human body's physical mechanism for taste.

"The main taste sensors that people think about are in the tongue, but you also have taste receptors in other parts of the body, including the esophagus and in the stomach," Raimi-Abraham said. A flavored formulation which masks bitterness in the mouth can therefore leave a nasty aftertaste when the active ingredient dissolves in the stomach.

Despite these difficulties, pharmaceutical companies invest millions every year in trying to address this palatability problem. "There are lots of different strategies: sweeteners and flavorings, coatings, tweaking the chemical structure, adding modifiers to change the mouth feel and mask the bitterness. And all this, taking into account patient differences such as age that influence taste," Raimi-Abraham said. "I think the reason why some medicinal products still have a bitter taste is because it's an art as well as a science to get that formulation strategy for the overall taste right."

The Cairo Fossil Forest is a unique collection of 385 million-year-old trees preserved in an abandoned quarry in upstate New York. The forest holds some of the oldest trees in the world, as well as the oldest known examples of trees with leaves and thick, woody trunks, researchers say.

"The Cairo site is very special," Christopher Berry, a paleobotanist at the University of Cardiff in the U.K., told Science Magazine when the discovery was announced in 2019. "Standing on the quarry surface we can reconstruct the living forest around us in our imagination," Berry, who was one of the scientists that found the site in 2009, added.

The remains of ancient trees are buried beneath the quarry floor, but they form patterns on the surface that reveal where tree trunks and roots once anchored into the ground. Some of the fossilized roots are almost 6 inches (15 centimeters) thick, Science Magazine reported, and the biggest root networks stretch 36 feet (11 meters) away from the trunks.

The trees likely belong to Archaeopteris, an extinct group of trees with fern-like leaves that is related to modern trees. Research suggests Archaeopteris trees grew more than 66 feet (20 m) tall toward the end of the Devonian period (419.2 million to 358.9 million years ago), which is also known as the "age of fishes" due to the huge diversification that happened in this animal group.

The first Archaeopteris trees marked a turning point in Earth's history, because they helped to suck up and lock away carbon dioxide (CO₂) from the air, shifting the composition of the planet's atmosphere. These plants also accelerated a process called weathering, which occurs when roots jumble and break up rocks, exposing them to air and triggering a chemical reaction that turns CO₂ into carbonate ions. These ions eventually end up in the ocean and bind together to form limestone, experts told Science Magazine.

Before the Cairo Fossil Forest discovery, the oldest found Archaeopteris trees were 365 million years old, Berry said. The discovery of the Cairo Fossil Forest in 2009 suggests these prehistoric trees evolved at least 20 million years earlier than that, but it's still unclear exactly when they first appeared on Earth.

Related: 23 million-year-old petrified mangrove forest discovered hiding in plain sight in Panama

Despite being the earliest example of leaves and thick trunks appearing in trees, the Cairo Fossil Forest isn't the oldest in the world. In 2024, scientists discovered 390 million-year-old plant fossils in the southwest of England that dethroned the Cairo Fossil Forest as the earliest known forest. These older fossils belong to an extinct type of plant that looked like palm trees and are thought to be closely related to ferns and horsetails.

"They've got a long central stem and what look like palm fronds coming off, but those palm fronds aren't really leaves — they're actually just lots of twiglets," Neil Davies, a professor in the Department of Earth Sciences at the University of Cambridge in the U.K., told Live Science at the time.

Similar plants to those found in southwestern England have been discovered just 25 miles (40 kilometers) away from the Cairo Fossil Forest in Gilboa, New York. The Gilboa Fossil Forest is 382 million years old and was first excavated in the 1800s. It held the title of "world's oldest forest" until researchers discovered the forest in Cairo.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

Scientists in Australia are deep-freezing the shoot tips of a critically endangered tree to preserve its DNA in case the species goes extinct.

Only 380 specimens of the angle-stemmed myrtle (Gossia gonoclada) remain in the wild, with about 300 of them concentrated in the City of Logan area in southeast Queensland. If scientists manage to cryopreserve a diverse collection of genes from the species, there is a good chance they could resurrect it if it ever dies out, researchers said.

"The most important thing is preventing its continuing decline in the wild as this is where the plant is providing ecological functions and potentially cultural significance," Alice Hayward, a plant molecular physiologist at the University of Queensland who supervises the project, told Live Science in an email. But "by capturing and keeping alive the remaining diversity of this species in cryobanks it effectively provides a back up storage device for the species," Hayward said.

The angle-stemmed myrtle is a small tree that grows along waterways in Australia's dry rainforests. It has glossy leaves, square stems and sweet, fleshy fruit that may be a food source for bats and birds, Hayward said. "There has been limited research on its ecological interactions but it likely aids in river bank stability and biodiversity," she said.

A combination of habitat loss, rising temperatures and a deadly fungal disease called myrtle rust has drastically reduced the number of angle-stemmed myrtle plants in Australia since 2010. Myrtle rust is caused by the exotic fungus Austropuccinia psidii, which attacks the newly grown parts of trees and shrubs in the Myrtaceae family, deforming the plants' leaves, stunting their growth and decreasing their fertility.

To save the angle-stemmed myrtle from extinction, scientists are designing a method to freeze plant tissues that can later regenerate a full tree whenever needed. Although seeds contain reproductive material, they are not suitable for this project, both because of their reduced fertility from myrtle rust infections and because they likely won't survive long-term cryopreservation, Hayward said.

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So instead, Hayward and Jingyin Bao, a doctoral student at the University of Queensland, plan on preserving the angle-stemmed myrtle's shoot tips — the uppermost and actively growing parts of the plant — at ultra-low temperatures of minus 321 degrees Fahrenheit (minus 196 degrees Celsius).

This involves growing sterile shoots in a jelly and harvesting the tips before treating them with a cryoprotective solution and freezing them in liquid nitrogen, ABC News reported. Cryoprotective solutions protect plant cells during freezing by minimizing the formation of damaging ice crystals, Hayward said. Without these solutions, water inside the cells would expand, and the cells would burst; but with the solutions, the water turns "glassy" instead, she said.

The method already works for the sweet myrtle (Gossia fragrantissima), which is a small tree closely related to the angle-stemmed myrtle. After freezing sweet myrtle shoot tips, Bao achieved a 100% survival rate and managed to regrow all the plants, Hayward said. "We are transitioning this to gonoclada with some success and still working to improve the survival," she said.

Once the researchers land on a method for the angle-stemmed myrtle, they still need to make sure that they have enough genetic diversity in their samples to regrow a healthy population of trees.

"It is important that there is sufficient genetic diversity saved to provide the best chance of species survival in the future, especially if there happens to be any natural tolerance to myrtle rust or changing climate conditions," Hayward said. "Given the threats to this species in the wild due to habitat loss and invasive species including myrtle rust this needs to happen fast."

So far, Hayward and Bao haven't found any disease- or climate-resistant specimens in their sample, but City of Logan authorities and their partners are working to identify resistant individuals, Hayward said. "We want to preserve the most diverse individuals, whether tolerant or not, to provide a basis for future breeding," she explained.

And it's not just the angle-stemmed myrtle that needs preserving in this way, Hayward said. "We need Australia and the world to implement cryobanks to ensure we can bank the diversity of … foods and endangered plants for future generations," she said.

Scientists in China have created rainbow, glow-in-the-dark succulents by injecting colorful "afterglow" particles into the leaves that absorb, and then gradually release, light.

The luminescent succulents shone for up to two hours, outperforming similar, material-engineered plants, according to a new study. The invention paves the way for sustainable, plant-based lighting to illuminate outdoor and indoor spaces, researchers said.

"Imagine glowing trees replacing streetlights," study lead author Shuting Liu, a researcher at South China Agricultural University, said in a statement. "The particles diffused in just seconds, and the entire succulent leaf glowed."

Researchers have made glow-in-the-dark plants before, both with genetic engineering and material engineering. Genetic engineering approaches harness bioluminescent genes that already exist in certain plants, such as phytoplankton — but these genes have a limited, mostly green, color range, according to the study. Material engineering techniques involve injecting light-emitting particles into plant leaves to make them glow, but these methods have so far only generated dim light.

For strong luminescence, light-emitting particles have to be small enough to diffuse through a plant's tissues, but also big enough to emit a visible glow. Previous experiments using nanoparticles derived from firefly luciferase, the enzyme that creates bioluminescence in fireflies, produced only a faint glow that dropped sharply after 30 minutes.

For the new study, Liu and her colleagues used light-emitting phosphor particles that were roughly the width of a human red blood cell (6 to 8 micrometers). The micron-sized particles were large enough to produce a strong glow while traveling through the plants freely, Liu said. "Smaller, nano-sized particles move easily within the plant but are dimmer," she said.

Related: Scientists invent photosynthetic 'living' material that sucks CO2 out of the atmosphere

The researchers published their findings Wednesday (Aug. 27) in the journal Matter.

Micron-sized particles worked for succulents but not for other plants tested in the study, including bok choy (Brassica rapa chinensis) and golden pothos (Epipremnum aureum). The researchers used Echeveria "Mebina" succulents, which have blue-green leaves with red tips. Unlike bok choy and golden pothos, these succulents have relatively large gaps between their cells, meaning that micron-sized particles can travel through the plant, according to the study.

The researchers injected phosphor particles into the leaves of Echeveria "Mebina" and charged the plants in sunlight or indoor LED light for a few minutes, obtaining the same afterglow effect in both experiments. Green particles produced the longest glow, with the plants emitting light for up to 2 hours and rivaling a small night lamp at their brightest, according to the study.

The team produced the world's first multicolored luminescent plants by injecting blue, green, red and blue-violet phosphor particles into the leaves of some succulents. The scientists also built a plant wall of 56 succulents that produced enough light to see nearby objects and read text in the dark, according to the statement.

"I just find it incredible that an entirely human-made, micro-scale material can come together so seamlessly with the natural structure of a plant," Liu said. "The way they integrate is almost magical."

Luminescent succulents could one day be a low-carbon lighting solution, according to the study. The researchers hope to produce the same effect in other plants, which could be exposed to sunlight and charged up like batteries to provide decorative and practical lighting.

"The process is straightforward and cost-effective and achieves luminescence within 10 min, paving the way for practical applications in plant-based lighting," the researchers wrote in the study.

Random mating between wild tomato plants and potato-like species 8 million to 9 million years ago may have given rise to one of our favorite carbs: the potato.

Together with 107 extant, wild potato species, the cultivated potatoes we know today (Solanum tuberosum) belong to the lineage Petota. New research suggests that this lineage, or group of closely related species, emerged from interbreeding between the ancestors of two other lineages: Tomato, which consists of 17 living species, including the salad essential Solanum lycopersicum, and Etuberosum, which has three living species native to South America.

"From an evolutionary perspective, we had an unresolved [disagreement] in the relationships between Tomato, Petota and Etuberosum lineages," Sandra Knapp, a research botanist at the Natural History Museum in London and co-author of the new study, told Live Science in an email.

The importance of interbreeding in this case, Knapp said, is that it created new combinations of genes in the Petota lineage, giving rise to tubers — the swollen, underground organs that store water and nutrients, which humans eat. The ancestors of modern Tomato and Etuberosum plants did not have tubers, and these structures have not appeared in either lineage since they interbred to produce a hybrid.

"Our findings show how a hybridization event between species can spark the evolution of new traits, allowing even more species to emerge," study co-author Sanwen Huang, a professor of agricultural genomics at the Chinese Academy of Agricultural Sciences, said in a statement. "We've finally solved the mystery of where potatoes came from."

The researchers analyzed the genomes of 128 Petota, Tomato and Etuberosum plants to resolve the evolutionary relationships between these lineages. They used advanced genomic tools that were not previously available, explaining why scientists haven't obtained these results before, Knapp said. The team published its findings Thursday (July 31) in the journal Cell.

Related: 2 plants randomly mated up to 1 million years ago to give rise to one of the world's most popular drinks

The analysis revealed "mosaic-like" genetic patterns in Petota that represented an even mix of DNA inherited from both Tomato and Etuberosum, dating the origin of potatoes to an interbreeding event between the two lineages between 8 million and 9 million years ago, the researchers wrote in the study.

An ancient hybridization event between Etuberosum and Tomato is possible because these lineages shared a last common ancestor between 13 million and 14 million years ago, according to the study. Despite evolving independently after this common ancestor disappeared, Etuberosum and Tomato plants may still have had enough in common genetically to interbreed 5 million years later.

The potato plants resulting from this match produced tubers, which the researchers linked to several genes. Notably, the team identified SP6A, a gene that came from the Tomato lineage but evolved in potatoes to provide instructions on when to make tubers. The researchers also highlighted the gene IT1 as involved in forming tubers, but this gene came from the Etuberosum side, according to the study.

Tubers helped potato plants conquer new soil at a time when the Andes mountains were undergoing rapid uplift, the researchers suggest. Interbreeding "led to a reshuffling of genes such that the new lineage produced tubers, allowing these plants to expand into the newly created cold, dry habitats in the rising Andes mountain chain," Knapp said.

Potato plants' ability to store nutrients and water likely helped them survive in harsher environments than Etuberosum and Tomato plants. This not only promoted the geographical expansion of potatoes, but it also prevented mating with Etuberosum and Tomato plants, allowing Petota to evolve into a completely new lineage, according to the study.

"Evolving a tuber gave potatoes a huge advantage in harsh environments, fueling an explosion of new species and contributing to the rich diversity of potatoes we see and rely on today," Huang said.

A palm swamp peatland in the Peruvian Amazon that normally absorbs more carbon than it releases each year has switched to being carbon neutral, even with no major disturbance by local people.

On their face, the findings, reported June 30 in the journal Geophysical Research Letters, may seem like a sign of trouble. However, experts say there's more to the story.

Peatlands play a crucial role in the carbon cycle by absorbing carbon dioxide. In Peru, they cover some 22,000 square miles (56,000 square kilometers) — less than 5% of the country's total area. Yet they store about 5 gigatons of carbon belowground — roughly equivalent to all of the carbon stored aboveground in vegetation in Peru.

It's a similar picture globally, where, according to the International Union for Conservation of Nature, peatlands cover about 3% of the world's land area but store at least 550 gigatons of carbon — more than twice the carbon stored in all the world's forests.

"Peatlands represent such a small land area on Earth, but they are massively important as stocks of carbon," Jeffrey Wood, a biometeorologist at the University of Missouri and lead author of the new study, told Live Science. "These systems have accumulated gigatons of carbon over tens of thousands of years."

So what has happened in Peru?

Key ecosystems

Wood and his colleagues have been studying the dominant kind of Amazonian peatland in Peru's Quistococha Forest Reserve. These swampy ecosystems, known locally as aguajales, are dominated by moriche palms (Mauritia flexuosa).

These key ecosystems develop in areas that flood seasonally, with the palms providing a fruit called aguaje for locals, as well as for macaws, monkeys, tapirs and agoutis. These areas are densely vegetated havens for many birds, reptiles and mammals.

Crucially, the plants that grow there absorb carbon dioxide (CO2) from the atmosphere through photosynthesis. But because the area is waterlogged, their dead leaves and other fallen matter usually accumulate as peat in the low-oxygen environment, which traps carbon instead of fully decomposing and releasing it back into the atmosphere.

Wood and his colleagues found that the peatland switched from being a strong carbon sink in 2018 and 2019 to being about carbon neutral in 2022.

Yet there were no obvious signs of human effects on the ecosystem, Wood said. "The peatland hadn't been drained and the trees hadn't all been cut down or taken down by a storm," he said. "It also wasn't a major drought year or a major heat wave."

Instead, the researchers found that two factors led to the change. The first is that prolonged cloudless periods and higher sun intensities limited the photosynthesis of the plants, thus restricting their growth and how much carbon dioxide they absorbed.

The second was that lower water levels left more of the top of the peat exposed. This meant more oxygen was available to bacteria in the decaying matter, which decomposed faster, releasing more carbon dioxide and methane gases than usual.

Lydia Cole, a conservation ecologist at the University of St Andrews in Scotland who wasn't involved with the work, told Live Science that normally, in the course of a year, a peat ecosystem goes through periods of greater carbon uptake and time of greater carbon release, but on average, the result is usually a net absorption of carbon.

"Across one landscape, you'll have areas that are releasing carbon and areas that are sinks, and peatlands often have a microtopography," she explained. "So it might be that on a mound you'll get more decomposition and emissions of carbon and in hollows, which are wetter, you'll get sequestration. But the net over the course of a year is what we're really interested in."

At first it seemed counterintuitive to Wood that more sunlight would cause less photosynthesis. But it could happen because the Quistococha rainforest is generally covered in thick clouds, he said.

"The plants are being exposed to much more light than they can deal with," Wood told Live Science. When there is too much light and heat, the plants close the pores, called stomata, on their leaves, through which they take in CO2 and release oxygen during photosynthesis.

That's why photosynthesis is often lower at midday in rainforests, and Wood and his colleagues saw that standard pattern in Peru. But what had changed was what happened in the normally very productive mornings and afternoons, where photosynthesis dropped below normal levels in the higher light intensities.

One big question is whether the peatland will return to being a carbon sink, stay carbon neutral, or progress to releasing huge volumes of its stored carbon.

Wood is optimistic that the peatland will regain its sink capacity in future years.

Chris Evans, a peatland biogeochemist at the UK Centre for Ecology & Hydrology in Wales who wasn't involved in the work, also advised against drawing conclusions based on one year. "I would expect a natural peatland to fluctuate between net sinks and neutral from year to year depending on weather conditions, particular[ly] if water levels get drawn down," Evans told Live Science. "I certainly would not interpret this as evidence of a long-term change in the carbon balance."

Human impacts

However, the change observed by Wood and his colleagues happened in the absence of an obvious human disturbance — but that doesn't mean humans haven't affected the sink or won't in the future.

"One ecosystem is not functioning as an island," Cole said. There are areas of grasslands and settlements in the wider region, which were created after deforestation. This could have changed local weather patterns, which then feed into longer-term climate changes, she said.

It's uncertain how climate change will influence tropical peatland in Peru or elsewhere in the Amazon, but any effects on cloud cover or changes in the water table are likely to affect the strength of these carbon sinks, Wood said.

Jean Ometto, head of the Centre for Earth System Science at Brazil's National Space Research Institute, who wasn't involved in the work, told Live Science that water table variation is a major issue in the Amazon generally.

"In the Brazilian Amazon, we're facing extremes of floods and extremes of drought," he said. "The water table coming down can be a long-term process because of the frequent droughts. With the change in climate, that might be a permanent process, which is a huge problem."

The findings should be taken seriously but be put into perspective, Cole said. "We need to not cry wolf about this," she said. "But we also need to think really seriously about how we protect peatlands that remain healthy and how we can re-wet those peatlands that still have the capacity to sequester carbon into the future."

Our understanding of plant and tree roots may have been somewhat shallow. New research reveals many plants have a hidden second set of roots that extend far deeper into the soil.

According to a new study published June 17 in the journal Nature Communications, this second layer of roots extend over 3 feet (1 meter) down and enable the plant to access deeper soil nutrients.

The findings suggest plants might transport and store carbon deeper in the ground than expected, which could help scientists develop longer-term underground carbon storage to mitigate climate change impacts.

To analyze these deeper rooting systems on a large scale, the researchers used a database of soil samples collected from more than 6 feet (1.8 m) below the surface. From this, they detected root patterns and soil composition from 44 sites. These sites were from a range of climate zones and ecosystems across the globe, from the Alaskan tundra to rainforests in Puerto Rico.

The findings showed about 20% of the sites around the world had roots that peaked in mass twice along their depth, meaning these plants had a second, deeper system of roots — a phenomenon the researchers call "bimodality."

"We were very surprised by how frequently we find bimodal patterns," study lead author Mingzhen Lu, an ecologist at New York University, told Live Science in an email. For a long time scientists assumed plants had fewer and fewer roots as they went deeper into the ground, Lu said.

Related: 'This should not be published': Scientists cast doubt on study claiming trees 'talk' before solar eclipses

The second layer of roots typically reached soils rich in nutrients like nitrogen, enabling plants to tap into these deep-soil resources. Plants get most of their resources from surface soil, for example through rainfall or leaves falling on the ground, Lu said. But a deeper, secondary way to tap into nutrients could boost the resources available to plants if they're not sufficient at the surface.

As only 1 in 5 plants had these roots, this could indicate an opportunistic response given particular conditions, like drier or more unreliable water in surface soil. "It is more of a choice," Lu explained. "Given enough motivation… plants will explore deeper and make use of these deep resources."

Soil scientists need to look deeper to understand what's actually happening underground, the researchers said. "Sampling 10 centimeters [4 inches] deep, or 30 centimeters [12 inches], simply won't cut it," Lu said. "We just miss too much of what's actually going on in the soil."

The idea that plants have deeper roots is not new, Alain Pierret, a soil scientist at the French National Research Institute for Sustainable Development who was not involved with the new study, told Live Science in an email. The traditional theory of diminishing roots deeper into the ground has previously been questioned, and the deep rooting phenomenon has been studied, but not in sufficient detail, Pierret added.

"What is new and remarkable is the dedicated network of field stations used to observe relatively deep root profiles across a range of biomes," Pierret said. He added that more work is needed to fully understand what's going on in these deep rooting systems, and that the deep root systems are probably not only bimodal but likely multi-modal, with even more roots deeper into the ground below the depth the new study focused on.

The findings also mean scientists may have underestimated the potential for carbon storage in soil, according to the researchers. Soil can hold more carbon than the atmosphere, so some climate mitigation measures focus on crops that take in carbon from the air and store it in roots and soil.

"Our current terrestrial carbon budget [is] most likely incorrect, with potentially significant implications for climate change mitigation strategies and policies," Pierret said.The research team is now investigating what these findings mean for carbon storage. "The good news is plants may already be naturally mitigating climate change more actively than we've realized," Lu said in a statement. "We just need to dig deeper to fully understand their potential."

A university student has discovered an elusive fungus that produces chemicals with similar effects to the psychedelic drug LSD.

Corinne Hazel, an environmental microbiology major at West Virginia University in Morgantown, spotted the fungus growing on morning glories. These flowering plants belong to a large family with many species, and Hazel specifically found the fungus in a variety of Mexican morning glory called "Heavenly Blue." The fungus also grows on varieties called "Pearly Gates" and "Flying Saucers," according to a recent study published April 22 in the journal Mycologia.

Morning glories were already known to contain a class of chemicals called ergot alkaloids. These chemicals, made exclusively by fungi, are the same class that the Swiss chemist Albert Hofmann used to create LSD in the 1930s. Hofmann worked with the fungus Claviceps purpurea, commonly found on rye, to synthesize LSD; he came to suspect that Mexican morning glories must have a similar chemical-producing fungus after learning that the plants were used for their hallucinogenic properties. However, that fungus has remained elusive — until now.

Hazel made the discovery while searching for the long-hypothesized fungus with Daniel Panaccione, a plant and soil sciences professor at West Virginia University. She is now investigating the best ways to grow the fungus, which the team thinks may have medicinal value.

"I'm lucky to have stumbled into this opportunity," Hazel said in a statement. "People have been looking for this fungus for years, and one day, I look in the right place, and there it is."

Related: Scientists show how LSD blows open the doors of perception

Indigenous Mesoamerican cultures were the first to recognize that Ipomoea tricolor — commonly called Mexican morning glory or just morning glory — has psychoactive properties. Knowing of I. tricolor's cultural significance, Hofmann identified the chemicals responsible. The chemicals he found were previously only known to come from fungi, but his attempts to observe a fungus on the plant were unsuccessful, according to the study authors.

Researchers have since identified two separate fungi that make ergot alkaloids on two other morning glory species, and they've found additional, molecular evidence for the presence of ergot alkaloid-producing fungi on I. tricolor. However, the identity of the fungus itself remained a mystery.

Now, with the new study, the elusive I. tricolor-associated fungus has finally been identified. Hazel spotted evidence of the fungus on the plant's seeds.

"We had a ton of plants lying around and they had these tiny little seed coats," Hazel said. "We noticed a little bit of fuzz in the seed coat. That was our fungus."

Hazel and Panaccione collected a DNA sample from the fungus and sent it away for sequencing. The sequencing revealed that the fungus was related to the fungi previously found on the two other morning glories. Hazel and Panaccione named the new species Periglandula clandestina, with the species name referencing the hidden, or clandestine, nature of the fungus.

P. clandestina is very efficient at producing large amounts of ergot alkaloids, the researchers found. The toxic nature of these chemicals likely helps protect the plant from being eaten, so it's thought to be a symbiotic relationship.

However, ergot alkaloids are a problem in agriculture, as they contaminate food humans eat and grasses used to nourish livestock, therefore posing a threat to humans and the animals people eat. C. purpurea, the fungi used to invent LSD, would contaminate grain and poison those who consumed it, triggering an illness called "ergotism" that involved gangrene, convulsions, double vision, and of course, hallucinations.

That said, ergot alkaloids can also be used in medicines to treat conditions like migraines. The newly discovered fungus could therefore have a role in medicine and agriculture, the study authors propose.

"Many things are toxic," Panaccione said. "But if you administer them in the right dosage or modify them, they can be useful pharmaceuticals. By studying them, we may be able to figure out ways to bypass the side effects. These are big issues for medicine and agriculture."

Hofmann was pursuing the medicinal properties of fungus when he first synthesized LSD. He only discovered LSD's powerful psychoactive effects when he accidentally got a drop of it on his skin — and then deliberately ingested more a few days later.

This article is for informational purposes only and is not meant to offer medical advice.

On the middle-altitude slopes of Mount Kilimanjaro grows a strange plant not found anywhere else on Earth. The giant groundsel, a plant that looks like a pineapple crossed with a saguaro cactus, colonized the flanks of Africa's tallest mountain up to 1 million years ago and has not budged since.

Kilimanjaro's giant groundsels (Dendrosenecio kilimanjari) grow at altitudes of between 9,200 and 13,100 feet (2,800 to 4,000 meters), where they get just enough rainfall to survive, according to the tour operator Tranquil Kilimanjaro. The plants have evolved adaptations to the harsh conditions on the mountain, including water storage systems and a protective jacket of dead leaves.

Located in northeast Tanzania, the base of Mount Kilimanjaro is hot and humid, but temperatures at the summit, which is 19,340 feet (5,895 m) above sea level, can drop to minus 20 degrees Fahrenheit (minus 29 degrees Celsius). The mountain "creates its own weather," according to the tour operator Climbing Kilimanjaro, with baking sunshine, snow, rain and bitter winds all possible at different altitudes at any time of the year.

Giant groundsels have evolved to cope with this variable climate. Their thick stems are topped with a crown of sturdy leaves covered in hairs that limit how much water escapes the plant by evaporation. Both the stem and the leaves store water for when the climate is dry, usually from December to March and June to October.

The plants are also well equipped to survive a wide range of temperatures. When their leaves die, they fold over the stem and create a thick layer of insulation against the cold. Additionally, giant groundsels ooze “antifreeze” substances that enable the plants to grow above the tree line.

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Most giant groundsels aren't much taller than a human, but some can reach 20 to 30 feet (6 to 9 m) tall. Their vertical growth is another adaptation to the conditions on Mount Kilimanjaro, as the plants receive more sunlight the higher they grow, according to the tour operator Altezza Travel.

However, growth takes time. Giant groundsels grow by 1 to 2 inches (2.5 to 5 centimeters) per year, according to tour operators, meaning that the tallest specimens may be at least 100 years old.

According to a genetic study by botanists, published in the journal PNAS, groundsels colonized Kilimanjaro within the past 1 million years and giant groundsels evolved as certain species adapted to the hostile conditions and migrated up the mountain.

Giant groundsels are pollinated by insects, which visit the plants' yellow flowers. After pollination, the flowers turn into fluffy seed heads, and these are carried by the wind to new locations.

Giant groundsels are found on Mount Kilimanjaro's Shira plateau and in the area around Barranco Camp, according to the Kilimanjaro National Park website. The best walking trails to see the plants are the Northern Circuit, the Lemosho route and the Machame route, according to tour operators.

Hikers should be careful not to touch or damage giant groundsels, which provide food and shelter for birds and small mammals. The plants' deep roots also help stabilize the soil, slowing the rate of erosion on Kilimanjaro, according to Tranquil Kilimanjaro.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

The idea that trees communicate with each other during an eclipse and synchronize their behavior — as has been widely reported recently — is a compelling one. The fascinating idea sprang out of research detecting bioelectric signals in spruce trees (Picea abies) in Italy's Dolomite mountains during a 2-hour-long partial solar eclipse. But many researchers aren't convinced, saying the number of trees studied is tiny and that there are more plausible explanations for the results.

Some 6,600 feet (2,000 meters) above sea level, Alessandro Chiolerio, a physicist at the Italian Institute of Technology, Monica Gagliano, an ecologist at Southern Cross University in Australia, and their colleagues attached remote sensors to three healthy spruce trees — two of about 70 years old and the other around 20 years old — and to five tree stumps.

The sensors were there to detect electrical currents created when charged molecules travel through the cells of living organisms.

"Our results demonstrated that spruce trees exhibited synchronized changes in their bioelectrical activity in anticipation of a solar eclipse," Gagliano told Live Science. "Remarkably, this synchronization began several hours before the eclipse occurred, suggesting not just a passive reaction to darkness but an active, anticipatory response."

"The strongest signs of this early response were observed in older trees, hinting at a memory-like capacity linked to their age and environmental history," she said. "This study provides the first evidence that trees in a forest can behave as a coordinated collective system — functioning more like an integrated network than just as isolated individuals."

So, what exactly is going on in this work published April 30 in Royal Society Open Science, and how seriously should we take it?

"There is strong concern among my colleagues that this paper was published," James Cahill, a plant ecologist at the University of Alberta in Canada, told Live Science. "The paper doesn't meet what I would say are the basic standards needed for science. Its sample size is three, which is very low and they have a super large number of variables that they're testing — over 10 — and you're always going to find a pattern if you do something like that."

Related: Tropical tree in Panama has evolved to kill its 'enemies' with lightning

Many plants and animals respond to the day-night cycles of light and dark, so plants responding to approaching darkness shouldn't be a surprise, he said.

"If you turn off the lights in a greenhouse or at night, every plant will show reduced water transpiration and reduced photosynthesis. Is that coordination?" asked Cahill. This would also alter their bioelectrical signals, and every biological material has bioelectrical signals, he added, so there's nothing fancy in detecting changes to these.

It's also unlikely there's an evolutionary survival advantage to responding to an eclipse, Cahill pointed out, given how briefly and infrequently they occur. Instead, he thinks the plants are responding with capabilities that have evolved for a different reason. "It is very easy to imagine that sensory systems evolved for other purposes that are then hijacked in an eclipse. Plants respond to darkness and an eclipse causes darkness. But it doesn't mean that the eclipse caused the response to darkness."

And when it comes to the bioelectrical signals changing before the eclipse rather than during it, there's also a simple possible answer, he said. "Plants have elaborate sensory systems for detecting light and a lot of plants can detect UV light and blue light changes and those tend to come first across the horizon. A lot of plants will start changing their photosynthetic machinery before sunrise," said Cahill. "I'm not sure this is anything different."

"It's disappointing that this paper is getting so much press because it's just an idea and there's not much here other than assertion," said Cahill. "This could have been replicated, it should be replicated. There's no understanding of why they are focusing on electrical signals instead of the photosynthetic rate. They also didn't compare this to just night and day, which is the obvious thing to do and that's very worrisome to me."

Other researchers approached by Live Science said similar things. "I don't think anything can be concluded from an experiment that does not include replicates," Justine Karst, a forest ecologist at the University of Alberta in Canada, told Live Science.

Researchers in the field are also skeptical about the idea that older trees responded more strongly.

There are three living trees in the study and there are assertions about young versus old, said Cahill, "but they only have one young plant and it's in a different site. And it's not even young, it's 20 years old."

Asked about the small sample size, Chiolerio told Live Science how difficult it was to spend whole days working at almost 7,000 feet above sea level to attach sensors to trees when temperatures go down to 5 degrees Fahrenheit (minus 15 degrees Celsius).

"Due to the complexity of the field setup — monitoring trees 24/7 in alpine conditions — we focused on a small number of carefully selected individuals. Despite the sample size, the data were robust and consistent across trees and sites," said Gagliano. "Still, this is an early study, and we view it as a foundation for broader research."

Karst compared the new findings to experimental studies that seemed to reveal a wood-wide web in which trees communicate and share resources via underground networks of mycorrhizal fungi. She was a co-author of work published in 2023 showing that there was insufficient evidence for the idea.

"I hoped that after the wood-wide web fell apart, journalists would be more skeptical about research claiming that 'trees talk'," said Karst.

Cahill is in favor of studying plant behavior to probe whether these organisms have cognition — he is doing work in that area himself — but says the level of evidence needs to be very high before claims are made.

"How would we test cognition in plants? I'm sympathetic to the idea of a different approach, but papers like this make it really hard to do very strong science in a controversial area," said Cahill. "It's very disappointing because the Royal Society has had a great reputation. But this should not be published."

In response to questions about the study's publication, The Royal Society Open Science sent Live Science the following comment.

"All research published by Royal Society Open Science goes through thorough peer review before being accepted."

They also noted the role post-publication discussion plays in their process.

"We encourage academic debate and constructive criticism of the research published in our journals. Any reader is able to submit a comment on research published in Open Science, this will be peer reviewed and published alongside an invited reply from the original authors."

Editor's Note: This story was updated at 1:10 p.m. EDT to include comment from the Royal Society Open Science.

Australia is rather isolated today, but around 120 million years ago, the island straddled the polar circle and formed a giant landmass with Antarctica. At that time, dinosaurs lived on this landmass — and thanks to a new study, we now know what their habitat looked like.

New illustrations show that "polar dinosaurs" roamed cool-temperate forests crisscrossed by rivers and carpeted with large ferns. These dinosaurs included small ornithopods — herbivorous dinosaurs with beaks and cheeks full of teeth — and small theropods, which were mostly carnivorous dinosaurs that walked on two legs and often had feathers, one of the study's authors wrote in The Conversation.

"What is now Victoria was once within the polar circle, up to 80 degrees south of the equator and shrouded in darkness for months at a time," wrote co-author Vera Korasidis, a lecturer in environmental geoscience at the University of Melbourne and a research associate at the Smithsonian's National Museum of Natural History. "Despite these harsh conditions, dinosaurs thrived here, leaving behind evidence of their existence at various palaeontological sites."

The amount of sunlight reaching the Antarctic Circle has remained the same over the eons, but the climate was much balmier during the Cretaceous period (145 million to 66 million years ago) than it is today, with temperatures averaging between 11 and 25 degrees Fahrenheit (6 to 14 degrees Celsius) warmer than current temperatures. The Early Cretaceous (140 million to 110 million years ago), in particular, stands out as one of the warmest periods in the past 500 million years of Earth's history, Korasidis wrote, ruling out the existence of polar ice caps.

Related: Dinosaurs might still roam Earth if it weren't for the asteroid, study suggests

Paleontologists have been studying rocks containing dinosaur fossils from the southern Australian state of Victoria for decades, but they have also been analyzing microscopic spores and pollen grains that may be from plant life that existed near the South Pole during the Early Cretaceous, Korasidis wrote.

For the new study, Korasidis and her co-author Barbara Wagstaff, a pollen and spore specialist at the University of Melbourne, examined nearly 300 pollen and spore samples from 48 sites along the Victoria coast. These samples, which date to between 130 million and 110 million years ago, shed light on the evolution of forests and floodplains where dinosaurs lived, Korasidis wrote.

The researchers published their findings and the first-ever reconstructions of Early Cretaceous polar landscapes Wednesday (May 7) in the journal Alcheringa.

Ancient conifers made up most of the forest canopy, while ferns — specifically, scaly tree ferns (Cyatheaceae), forked ferns (Gleicheniaceae) and another group of primitive ferns (Schizaeaceae) — dominated the understory, according to the study. The researchers noticed an abundance of flowering plants appeared starting around 113 million years ago, which agrees with the timing of the proliferation of flowering plants globally.

"The appearance of flowering plants in the landscape resulted in the extinction of numerous understorey plants," Korasidis wrote in The Conversation. "As a result, by 100 million years ago, the forests of Victoria included an open conifer-dominated forest canopy. Flowering plants and ferns featured in the understorey, alongside liverworts, hornworts, lycophytes and sphagnum-like mosses."

The changing vegetation likely influenced dinosaurs, with many expanding their diet to include flowering plants by the end of the Cretaceous, according to Smithsonian magazine.

Plants are an incredibly diverse group of organisms, ranging from tiny algae to majestic redwood trees. Plants have colonized nearly every environment on Earth, evolving ways to thrive in blistering deserts, salty coastlines and dripping rainforests. They support most life on Earth because they sit at the base of almost every food chain and pump out the oxygen we need to breathe.

Most plants have green leaves, and many have beautiful-smelling flowers that come in many sizes and every color of the rainbow.

Plants often rely on wind, water and animals (like bees, butterflies or birds — known as pollinators) to reproduce. To do so, plants transfer pollen from a male flower to a female flower. This process creates a seed, which then grows into a new plant that gets half its genes from the male "parent" and half from the female "parent." Some plants make more of themselves without this transfer process, creating a new plant that's essentially a clone of itself, meaning it carries all the same genes as its parent.

5 fast facts about plants

• Plants can communicate with each other by releasing chemicals when they are under attack.
• Despite not having brains, some plant species can "remember" things from the past and react accordingly.
• Some plants, like Venus flytraps, eat animals like flies or frogs.
• There are around 390,000 plant species in the world.
• Plants first evolved in the water, and then started growing on land about 400 million years ago.

Everything you need to know about plants

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• Where did the 1st seeds come from?
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• Why is grass green?

If a global catastrophe suddenly led to a nuclear winter, millions of people could starve. But now, scientists have figured out what crops we would need to grow to sustain a city if such a calamitous event occurred.

According to a new study, farming spinach, sugar beets, wheat and carrots in urban and near-urban areas could feed the population of a midsize city in a post-apocalyptic world.

The scientists built on previous research to determine the optimal crops to plant after a global catastrophe — such as nuclear war, extreme pandemics or solar storms. Their goal was to find the most efficient way to feed a person using the least amount of land.

"[The research] actually wasn't inspired by the current, you know, geopolitical environment," said study lead author Matt Boyd, founder and research director of Adapt Research, an independent research organization. "But it has turned out to be very relevant, obviously, to the current geopolitical environment," Boyd told Live Science.

Current events include unpredictable international politics, ongoing war in the Middle East and Europe, weaponized artificial intelligence and the ever-mounting destruction from climate change. In January, the Doomsday Clock, which indicates how close humanity is to a species-threatening disaster, ticked one second closer to midnight — the closest it has ever been to catastrophe.

In the new study, published Wednesday (May 7) in the journal PLOS One, the researchers looked at how the population of a midsize city could survive with agriculture in the event of a global disaster. The study examined two scenarios should disaster strike: what to grow in and around a city under normal climate conditions, and what to grow in the event of a nuclear winter.

The optimal crop to grow in a temperate city in normal conditions turned out to be a humble legume: peas. "Peas are a high protein food. They grow well in urban agriculture environments," Boyd said. "If you want to feed someone, growing peas minimizes the amount of land you need to feed that person."

However, pea plants are not frost-resistant. In the event of a nuclear winter — which could be caused by nuclear war, a supervolcano eruption or a huge asteroid strike — sunlight would be blocked "due to all the soot and everything that's been thrown up into the stratosphere," Boyd said. This in turn would lead to lower temperatures and make it harder for plants to photosynthesise.

In that scenario, a hardier combination of spinach and sugar beets are a better choice, the researchers found.

Related: 'Nuclear winter' from a US-Russia conflict would wipe out 63% of the world's population

Boyd and study co-author Nick Wilson, a professor of public health at the University of Otago, Wellington came to these conclusions in part by using the data from a meta-analysis of urban agriculture research that analyzed the yield of different crops in dozens of cities around the world.

Peas, for example, rose to the top in normal conditions because they require 3,143 square feet (292 square meters) of land to satisfy one person's caloric and protein needs for a year, whereas a combination of cabbage and carrots required 8,364 square feet (777 square meters), said Boyd — almost three times as much land.

The researchers chose Palmerston North in New Zealand, but the findings can apply to similar cities worldwide, the researchers said. With a population of roughly 90,000, it's a globally midsize city, Boyd said, plus "it's inland, like many cities around the world, and it has reasonably low density, suburban type housing, not sort of Manhattan-style skyscrapers and so forth."

The scientists then used Google imagery of Palmerston North to work out the total amount of available green spaces that could be used to grow crops, such as front lawns, backyards and parks.

"Surprise, surprise. The city can't feed all its people," Boyd said. If food is only grown within the city bounds, the available land can feed about 20% of the population with crops that maximize protein and food energy per square foot under normal climate conditions. That number shrinks to about 16% during nuclear winter.

To feed the rest of the population, people would need land immediately outside the city — about one-third of the size of the city's built urban area — to sow additional efficient crops. In the case of Palmerston North, that's about 2,817 acres (1,140 hectares), plus another 272 acres (110 hectares) of canola to convert into biodiesel to fuel tractors and other farm machinery.

In the land just outside the city, the study found that potatoes are ideal for a normal climate scenario, and a combination of 97% wheat and 3% carrots is the optimal ratio during a nuclear winter because they have a higher tolerance for colder temperatures.

Even in cities, "there is a ton of farmland that can be used to grow food," said Theresa Nogeire-McRae, a landscape ecologist at American Farmland Trust and affiliate faculty at Oregon State University, who was not involved in the study.

“People settled cities where they did for a good reason,” Nogeire-McRae told Live Science. “It was the rich soil near riverbanks. It's a good commodity. Let's not throw that away." She added that the methods of study were sound and the findings were reasonable.

Boyd noted there are a number of unknowns that would impact crop yield in the real world. Soil quality is a big variable, because lower quality soil would yield fewer crops. He also assumed a scenario where water systems were still flowing — "but you can imagine global catastrophe scenarios where there's additional obstacles and problems," he said. He also doesn't expect people will only eat peas for an entire year, but planting the most efficient crops minimizes the amount of land needed to feed a population.

Boyd said this study could be used as a first step for cities looking to use resilient urban agriculture in land use policy.

"Decisions that might seem optimal in one lens, maybe economically, may look a little bit less optimal if you were also including a lens like resilience, safety and well-being," he said.

Lightning is usually seen as a harbinger of destruction in forests, killing or damaging trees in their blasts. But in the lowland rainforests of Panama, one species of towering tropical tree may have evolved to use this force of nature to its advantage.

The tonka bean tree (Dipteryx oleifera) may actually benefit from being struck by lightning, according to a new study.

Scientists discovered that these trees not only survive these electrical encounters unscathed, but the lightning damages its competitors and the parasitic vines that cling to the tonka bean trees. The researchers published their findings March 26 in the journal New Phytologist.

"We started doing this work 10 years ago, and it became really apparent that lightning kills a lot of trees, especially a lot of very big trees," study lead author Evan Gora, a forest ecologist at the Cary Institute of Ecosystem Studies, told Live Science. "But Dipteryx oleifera consistently showed no damage," Gora said.

In tropical forests, lightning is a major cause of tree mortality — especially among the largest, oldest trees that play key roles in storing carbon and supporting biodiversity.

Understanding how lightning shapes forest structure and species composition could shed light on how resilient these ecosystems are in the face of climate change. But amid the destruction, the researchers noticed something surprising: one species seemed to be thriving.

Using a custom-built system of electric field sensors and cameras to track strikes, researchers studied nearly 100 lightning events in Panama'’s Barro Colorado Nature Monument.

Related: 'Gossiping neighbors': Plants didn't evolve to be kind to each other, study finds

To track the exact points where lightning bolts struck, the scientists developed a high-resolution detection system. An antenna array, placed throughout Central Panama, detected radio waves from lightning strikes. By analyzing the energy patterns recorded by each sensor in the array, the researchers could triangulate the strike with high accuracy.

When combined with on-the-ground surveys and drone imagery, the team could pinpoint the forest area that was struck and monitor the condition of the trees over time.

The researchers found that D. oleifera stood out as a species that consistently showed little to no damage after being struck by lightning.

To get a longer term picture of the effect of lightning strikes on tonka bean trees and their neighbors, the team analyzed decades' worth of tree plot records.

"Over those 40 years, there's a quantifiable, detectable hazard of living next to Dipteryx oleifera. [As a tree], you are substantially more likely to die than living next to any other big old large tree in that forest," Gora said.

On average, each lightning strike killed more than 2.4 tons (2 metric tons) of nearby tree biomass and nearly 80% of the lianas (parasitic vines) that infested the tonka bean' canopy.

Gora speculated that the key behind these trees' lightning resistance comes from their physical structure. Past studies suggested that the tree has high internal conductivity, enabling lightning current to flow through without building up damaging heat — like a well-insulated wire.

Because it tends to grow large — up to 130 feet (40 meters) — and live for centuries, a single tonka bean tree is estimated to be struck at least five times after reaching maturity, with each strike helping to clear out vines and competitors, opening up the canopy to help it thrive.

The researchers estimated being struck by lightning could result in a 14-fold increase in lifetime seed production, giving the species a major reproductive advantage.

Gregory Moore, a horticulturalist from the University of Melbourne who was not involved in the study, said that the findings likely apply to other species as well. "The sort of work could also apply to other tree-dominated plant communities such as woodlands or low woodlands where trees are widely separated, so nothing like a tropical forest," he said, adding that other tall trees are also likely targets of lightning strikes.

"We have long known that some trees can survive multiple lightning strikes," Moore said, pointing out that some tall trees survive Australian bush fires and end up towering over their neighbors, which makes them prime targets for lightning strikes.

"They are often referred to as stags because the top of the crown has been blown out, but they can survive for centuries after being hit by lightning," he said.

Gora and colleagues are now expanding their research to other forests in Africa and Southeast Asia to find out whether lightning benefits other species.

While walking in Big Bend National Park in Texas' Chihuahuan Desert, a park volunteer came across a fuzzy flower that turned out to be a never-before-seen species. The "woolly devil," as researchers have named it, is in the sunflower family and also represents a new genus.

This is the first time in nearly 50 years that a new plant genus has been described in a U.S. national park, since the discovery of the July gold shrub (Dedeckera eurekensis) in Death Valley National Park in 1976, according to a statement from the California Academy of Sciences.

The new discovery suggests that researchers are far from documenting all of the plant diversity of the Chihuahuan Desert, which covers parts of Mexico and the southwestern U.S.

"While many assume that the plants and animals within our country's national parks have probably been documented by now, scientists still make surprising new discoveries in these iconic protected landscapes," Isaac Lichter Marck, a botanist at the California Academy of Sciences and co-author of research describing the new species, said in the statement.

Discovering the woolly devil

In March 2024, the park volunteer, Deb Manley, shared photos of the flowers — which measured 1 to 3 inches (2.5 to 7.6 centimeters) across and were poking out from between desert rocks — to the citizen science platform iNaturalist, where an international community of botanists tried to identify the plant.

Manley and a team of botanists and biologists studied the flower's characteristics and conducted genetic analyses, comparing its DNA with those of species from herbaria at Sul Ross State University in Texas and the California Academy of Sciences. They confirmed the plant as both a new species and a new genus, and identified it as a member of the sunflower family, according to the research, which was published Feb. 18 in the journal PhytoKeys.

Related: Giant, fungus-like organism may be a completely unknown branch of life

The researchers chose the scientific name Ovicula biradiata. In Latin "ovis" comes from "sheep" and honors the desert bighorn sheep (Ovis canadensis nelsoni), an iconic and threatened desert animal. The plant has white and woolly leaves, with small, curved, red and white flowers that resemble horns. The flowers were found near a part of the park called Devil's Den, leading the team to name the species the "woolly devil."

The Chihuahuan Desert is North America's largest and most biologically diverse warm desert, and Big Bend National Park contains a huge amount of this biodiversity. Many species found in the park have limited distributions, found only within the park or just outside it.

So far, woolly devils are known to exist only in a small area of Big Bend National Park, and the researchers think that, based on its limited range, this plant might be particularly sensitive to changing weather patterns.

This part of the Chihuahuan Desert has faced recent severe drought conditions, and the problem is expected to worsen due to climate change. That means woolly devils could qualify as vulnerable and face a high threat of extinction.

"As climate change pushes deserts to become hotter and drier, highly specialized plants like the wooly devil face extinction," Lichter Marck said in the statement. "It's possible that we've documented a species that is already on its way out."

A new estimate suggests China is home to 142.6 billion trees, meaning the country has roughly 100 trees per inhabitant.

These numbers are considerable, given how densely populated China is, an expert told Live Science. Still, the total figure may be an underestimate due to the limitations of the technology used to count the trees, the authors of the new study said.

"The actual number could be higher," said Qinghua Guo, a professor in the Institute of Remote Sensing and Geographic Information System at Peking University and the lead author of the study. China's Ninth National Forest Resources Inventory counted an average of 426 trees per acre (1,052 trees/hectare) across the country in 2019, which is much higher than the new study's estimate of 279 trees per acre (689 trees/hectare), Guo told Live Science in an email.

The true number of trees could be somewhere in the middle, but more research is needed to figure out what it is, he said.

An accurate estimate of China's tree population is crucial to evaluating forest ecosystem conditions and the amount of carbon that is being locked away in trees, Guo said. He and his colleagues also created a detailed map showing the distribution of China's trees, which they say will help the country hit its ecological and climate targets.

Related: Massive sinkholes in China hold 'heavenly' forests with plants adapted for harsh life underground

"The study represents the first high-resolution mapping of tree density across China," Guo said. "Ultimately, this research contributes to China's approach to global sustainable ecosystem management and restoration."

To produce the estimate, the researchers used a laser-based mapping technique called lidar (light detection and ranging). The team has been collecting lidar data from drones since 2015, amounting to an area covering 540 square miles (1,400 square kilometers).

For the new study, the scientists counted the number of trees in this area using software called Lidar360 that incorporates artificial intelligence (AI). They then extrapolated the resulting tree density estimate to obtain a national figure, with the results published Feb. 6 in the journal Science Bulletin.

The technology is cutting-edge, but some features need ironing out, Guo said. For example, Lidar360 cannot detect trees growing below thick canopies. "In densely forested areas, overlapping canopies obstruct the accurate detection of mid-story and understory trees, leading to lower-than-actual tree counts," Guo said. Incorporating terrestrial lidar data and improving the software could provide more accurate tree counts, he added.

Despite certain limitations, the results broadly align with researchers' previous understanding of China's tree population, said Tom Crowther, an assistant professor in the department of environmental systems science at the Federal Institute of Technology Zurich. "Globally, there are closer to 400 trees per person, but in such a densely populated region, it makes sense that this number is lower," Crowther, who was not involved in the study, told Live Science in an email.

China's tree population may soon increase, however, because the country is planting seedlings at a dizzying rate. Tree counts could skyrocket this spring as drones are deployed to seed the "Great Green Wall" — a huge belt of trees in the north of China that is being planted to prevent the Gobi and Taklamakan deserts from expanding. The Great Green Wall project — also known as the Three-North Shelterbelt Forest Program — started in 1978 and is due to be completed in 2050, by which point it could hold 100 billion trees. The wall is already the world's largest seeded forest with more than 66 million trees, but its success in staving off desertification is debated.

The technology used for the study not only helps to count and map trees, but it could also optimize where China chooses to focus its tree-planting efforts.

"The fusion of high-precision data and intelligent models ensures that every tree can be planted in the most suitable location," Guo said.

The mass extinction that killed 80% of life on Earth 250 million years ago may not have been quite so disastrous for plants, new fossils hint. Scientists have identified a refuge in China where it seems that plants weathered the planet's worst die-off.

The end-Permian mass extinction, also known as the "Great Dying," took place 251.9 million years ago. At that time, the supercontinent Pangea was in the process of breaking up, but all land on Earth was still largely clustered together, with the newly formed continents separated by shallow seas. An enormous eruption from a volcanic system called the Siberian Traps seem to have pushed carbon dioxide levels to extremes: A 2021 study estimated that atmospheric CO2 got as high as 2,500 parts per million (ppm) in this period, compared with current levels of 425 ppm. This caused global warming and ocean acidification, leading to a massive collapse of the ocean ecosystem.

The situation on land is far hazier. Only a handful of places around the world have rock layers containing fossils from land ecosystems at the end of the Permian and beginning of the Triassic.

A new study of one of these spots — located in what is now northeastern China —revealed a refuge where the ecosystem remained relatively healthy despite the Great Dying. In this place, seed-producing gymnosperm forests continued to grow, complemented by spore-producing ferns.

"At least in this place, we don't see mass extinction of plants," study co-author Wan Yang, a professor of geology and geophysics at the Missouri University of Science and Technology, told Live Science.

The finding, published Wednesday (March 12) in the journal Science Advances, adds weight to the idea that the Great Dying was more complicated on land than in the seas, Yang said.

The great changover?

Yang and his colleagues looked at rock layers in Xinjiang that span the mass extinction event.

A major advantage of this now-desert site is that the rocks include layers of ash that hold tiny crystals called zircons. The zircons include radioactive elements — lead and uranium — that gradually decay, which enables researchers to determine how long it has been since the crystals formed. This means the researchers can more accurately date the rock layers here than they can at other sites.

Some of these layers also hold fossil spores and pollen. These fossils reveal that there wasn't a massive die-off and repopulation but a slow changeover of species, Yang said.

This is consistent with other evidence from Africa and Argentina, where plant populations seemed to have shifted gradually rather than dying off dramatically and then repopulating, said Josefina Bodnar, a paleobotanist at the National University of La Plata in Argentina who was not involved in the research.

Land plants "have a lot of adaptations that allow them to survive this extinction," Bodnar told Live Science. "For example, [they have] subterranean structures, roots or stems, that can survive perhaps hundreds of years." Seeds can also persist a long time, she added.

This survival may have been particularly possible at humid, high-latitude regions. The site in Xinjiang was once dotted with lakes and rivers, a few hundred miles from the coast. Other places where plant refuges have been found, such as Argentina, were also high-latitude in the Permian, far from the equator where temperatures were the hottest.

Yang and his colleagues found that during the late Permian and early Triassic, the climate became a bit drier in what is now Xinjiang — but not enough to cause deforestation.

This may have been a consequence of location, said Devin Hoffman, a researcher in paleontology at University College London who was not involved in the new study. Marine animals had no escape from global ocean acidification. But climate change on land wasn't uniform. The impact would have been most pronounced in the center of Pangea, which was a vast desert.

This means that in more temperate regions on land, survival could have been possible, Hoffman told Live Science. "You essentially have everything being pushed toward the poles and towards the coast, but on land you're able to escape some of the effects," he said.

The planet's memory

These findings have led to some debate over whether the greatest mass extinction ever deserves the moniker on land. "I will call it a crisis on land. I will not call it an extinction," said Robert Gastaldo, an emeritus professor of Geology at Colby College who was not involved in the new study, but who has collaborated with Yang in the past.

The end-Permian extinction is particularly interesting to scientists because it was driven by greenhouse gases, much like climate change today. The situation was far more extreme then: The polar ice caps melted completely — a situation that would cause sea levels to rise a staggering 230 feet (70 meters) today.

But humans may be nearly as deadly as giant volcanoes. A 2020 study, for example, found that a smaller extinction event at the end of the Triassic (201 million years ago) was driven by greenhouse gas pulses from volcanoes that were on a similar scale to what humans are expected to emit by the end of this century. Studying these ancient catastrophes can give us a sense of what to expect under atmospheric carbon dioxide levels people have never experienced, Gastaldo said.

"The planet has experienced it," he said. "The planet's memory is in the rock record. And we can learn from the rock record what happens to our planet under these extreme conditions."

Rather than warning each other of impending doom, plants may be better off hiding signs of distress from each other, or even lying about danger that isn't there, according to a new study.

"Plants can gain a benefit from dishonest signaling because it harms their local competitors, by tricking them into investing in costly herbivore defence mechanisms," lead author Thomas Scott, an evolutionary theoretician at the University of Oxford, said in a statement. "Our results indicate that it is more likely that plants will behave deceptively toward their neighbours, rather than altruistically."

Previous research shows that if another plant is being attacked by a herbivore or disease, neighboring plants may upregulate their defense responses, which can include producing chemical compounds that make the plant poisonous or unpalatable to herbivores or insects. These defenses are rather energetically costly for the plant to perform, so they won't put them up unless they are absolutely necessary.

However, supporting their neighbors doesn't make sense from an evolutionary perspective as plants are constantly competing with each other for sunlight and nutrients.

For a study published Jan. 21 in the journal PNAS, researchers modeled the evolutionary plausibility of plants acting altruistically, and compared this with the likelihood of these signals being sent for other reasons. Their mathematical models looked at different hypothetical scenarios to look for situations that would lead them to warn neighbors of an attack.

Related: Lost biblical tree resurrected from 1,000-year-old mystery seed found in the Judaean Desert

The researchers found that it is much more evolutionarily advantageous for plants to lie about an attack, sending signals of distress even when nothing is wrong and tricking their neighbors into wasting precious resources.

Plants can communicate via a vast underground fungal network connecting their roots, known as the mycorrhizal network — sometimes referred to as the "wood wide web." Between 80% and 90% of all plant species are connected to a mycorrhizal network, according to the scientific research organization Society for the Protection of Underground Networks (SPUN).

These fungi form symbiotic partnerships with plant roots, with the plants receiving nutrients and the fungi receiving food made by the plants from photosynthesis. Information about plant resources can be transmitted through these networks, according to the statement.

The team suggests two possibilities for why the previously observed distress signals from plants may have occurred. The first is that plants release an involuntary signal that they cannot suppress — like a blush in humans — that the nearby plants eavesdrop on. "Maybe just like gossiping neighbours, one plant is simply eavesdropping on the [other]," study co-author Toby Kiers, evolutionary biologist at Vrije Universiteit in Amsterdam and executive director of SPUN, said in the statement.

Alternatively, the fungi in the mycorrhizal network may communicate an attack to other plants nearby, as it benefits the network if all plants are protected.

"Mycorrhizal fungi rely on the plants on their network for carbohydrates, so it's important to keep these plants in good condition," Scott said.

"It could be beneficial for fungi to monitor their plant partners, to detect when one plant has been attacked, and then warn the other plants to prepare themselves," he added in an email to Live Science. "This could be beneficial for fungi because it helps them to protect their plant partners from herbivores and pathogens."

Melting ice high up in the Rocky Mountains has revealed an impeccably preserved forest, frozen in time for thousands of years.

Beartooth Plateau, which sits at an altitude of over 10,000 feet (3,000 meters), is a barren, tundra-like landscape. But it hasn't always been that way; an ancient forest lies beneath layers of ice.

Cooling temperatures about 5,500 years ago quickly encased this whitebark pine (Pinus albicaulis) forest in ice, preserving the trees in nearly perfect condition. Now, as ice patches frozen for millennia melt due to climate change, researchers are finding clues about what this ancient landscape was once like, and how it was preserved. They detailed their findings Dec. 30, 2024, in the journal PNAS.

"No one had any idea that these patches of ice had been around for thousands of years," David McWethy, an associate professor in the Department of Earth Sciences at Montana State University and co-author of the study, told Live Science. "Things looked dramatically different than they do today."

This ancient forest of whitebark pines thrived for centuries at much higher elevations than the same tree species that can be found in the region today. This is because the global climate went through a warm period between the end of the last ice age, about 10,000 years ago, and the time when these whitebark pines died over 5,000 years ago.

This high-elevation forest was once an active ecosystem, likely sustaining animals and the humans who hunted them. From the same ice patch, Craig Lee, an assistant professor at Montana State University and co-author of the study, has recovered a wooden shaft dating back 10,000 years. This wooden shaft was likely part of a spear used by humans to hunt.

"We don't think about how dynamic that alpine ecosystem has been through time: people were using it, animals were using it," Cathy Whitlock, director of the Paleoecology Lab at MSU and senior author of the study, told Live Science. "You go there now and it's beautiful — it's a very dramatic landscape — but it's a little stark."

The trees likely died because of the gradual cooling of the climate at the end of the warm period described above, McWethy said. Very soon after the trees perished, a series of volcanic eruptions released ash and other materials into the atmosphere, which led to further cooling. This volcanic cooling was abrupt enough that ice quickly surrounded the trees and preserved them until the present day.

The trees revealed by the melting Rocky Mountain ice patch look "like trees that you would see up in a windswept area," McWethy said — missing their bark but otherwise pristine. Until now, the ice patch has never melted, so the ice has protected the trees from deteriorating.

A frozen forest emerging "is not something I've heard of before," Philip Mote, an Oregon State University professor who was not involved in this study, but has studied snow conditions in the western United States for almost 25 years, said in an interview. "I'm sure all sorts of things got buried under the ice."

Climate change driven by human activity has accelerated the warming of high-elevation areas like Beartooth Plateau. As more ice patches melt, there is the potential to learn more about the past, but Whitlock said these discoveries are bittersweet.

"These kinds of discoveries are scientifically really interesting, but they're also a sad reminder of how fragile these alpine ecosystems are to climate change," Whitlock said.

Imagine a photograph of your great-grandparents, grandparents and parents side by side. You'd see a resemblance, but each generation would look distinct from its predecessors. This is the process of evolution in its simplest form: descent with modification.

Over many generations, a staggering amount of modification is possible. This is how the diversity of life on Earth came to be.

This idea, though, has long been misunderstood as a path that leads in one direction toward "higher" or "better" organisms. For example, Rudolph Zallinger's famous 1965 Time-Life illustration "The Road to Homo Sapiens" shows humans evolving in a stepwise fashion from ape-like ancestors to modern man.

Extending this perspective beyond humans, early paleontological theories about ancient life supported the idea of orthogenesis, or "progressive evolution," in which each generation of a lineage advanced toward more sophisticated or optimized forms.

But evolution has no finish line. There is no end goal, no final state. Organisms evolve by natural selection acting at a specific geologic moment, or simply by drift without strong selection in any direction.

In a recently published study that I carried out with Makaleh Smith, then an undergraduate research intern at Harvard University who was funded by the National Science Foundation, we sought to study whether a one-way model of reproductive evolution always held true in plants. To the contrary, we found that in many types of ferns — one of the oldest groups of plants on Earth — evolution of reproductive strategies has been a two-way street, with plants at times evolving "backward" to less specialized forms.

Related: Which animals are evolving fastest?

The path of evolution is not linear

Selection pressures can change in a heartbeat and steer evolution in unexpected directions.

Take dinosaurs and mammals, for instance. For over 150 million years, dinosaurs exerted a strong selection pressure on Jurassic mammals, which had to remain small and live underground to avoid being hunted to extinction.

Then, about 66 million years ago, the Chicxulub asteroid wiped out most nonavian dinosaurs. Suddenly, small mammals were relieved of their strong predatory selection pressure and could live above ground, eventually evolving into larger forms, including humans.

In 1893, Belgian paleontologist Louis Dollo introduced the idea that once an organism progresses to a certain point, it does not revert to a previous state in the exact way in which it evolved — even if it encounters conditions identical to those it once experienced. Dollo's law, as it came to be known, implies that specialization is largely a one-way street, with organisms accumulating layers of complexity that make backward evolution impossible.

While Dollo's law has been criticized, and its original idea has largely faded from popular discourse, this perspective still influences aspects of biology today.

Plants and the march of progress

Museums often depict animal evolution as a straight-line progression toward higher stages, but they're not the only sources of this narrative. It also appears in teaching about the evolution of reproduction in plants.

The earliest vascular plants — those with tissues that can move water and minerals throughout the plant — had leafless, stemlike structures called telomes, with capsules at their tips called sporangia that produced spores. The telomes did both of the plants' big jobs: converting sunlight to energy through photosynthesis and releasing spores to produce new plants.

Fossil records show that over time, plants developed more specialized structures that divided these reproductive and photosynthetic functions. Moving through plant lineages, from spore-bearing lycophytes to ferns to flowering plants, reproduction becomes more and more specialized. Indeed, the flower is often diagrammed as the end goal of botanical evolution.

Across the plant kingdom, once species evolved reproductive structures such as seeds, cones and flowers, they did not revert to simpler, undifferentiated forms. This pattern supports a progressive increase in reproductive complexity. But ferns are an important exception.

Evolving, but not always forward

Ferns have multiple reproductive strategies. Most species combine spore development and photosynthesis on a single leaf type — a strategy called monomorphism. Others separate these functions to have one leaf type for photosynthesis and another for reproduction — a strategy called dimorphism.

If the patterns of specialization seen broadly across plants were universal, we would expect that once a lineage of ferns evolved dimorphism, it could not shift course and revert to monomorphism. However, using natural history collections and algorithms for estimating evolution in ferns, Smith and I found exceptions to this pattern.

Within a family known as chain ferns (Blechnaceae), we found multiple cases in which plants had evolved highly specialized dimorphism, but then reverted to the more general form of monomorphism.

Lacking seeds gives ferns flexibility

Why might ferns have such flexible reproductive strategies? The answer lies in what they lack: seeds, flowers and fruits. This distinguishes them from the more than 350,000 species of seed plants living on Earth today.

Imagine taking a fertile fern leaf, shrinking it down and wrapping it up tightly into a tiny pellet. That's basically what an unfertilized seed is — a highly modified dimorphic fern leaf, in a capsule.

Seeds are just one highly specialized structure in a suite of reproductive traits, each building on the last, creating a form so specific that reversal becomes nearly impossible. But because living ferns don't have seeds, they can modify where on their leaves they place their spore-producing structures.

Our findings suggest that not all reproductive specialization in plants is irreversible. Instead, it may depend on how many layers of specialization plants have acquired over time.

In today's rapidly changing world, knowing which organisms or traits are "locked in" could be important for predicting how species respond to new environmental challenges and human-imposed habitat changes.

Organisms that have evolved down "one-way" paths may lack the flexibility to respond to new selection pressures in particular ways and have to figure out new strategies to change. In lineages such as ferns, species may retain their ability to "evolve backward," even after specialization.

Ultimately, our study underscores a fundamental lesson in evolutionary biology: There is no "correct" direction in evolution, no march toward an end goal. Evolutionary pathways are more like tangled webs, with some branches diverging, others converging, and some even looping back on themselves.

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

In this excerpt from "Oak Origins: From Acorns to Species and the Tree of Life" (University of Chicago Press, 2024), author Andrew L. Hipp explores the extreme conditions on Earth that gave rise to the oak tree (Quercus), with wild fluctuations in the climate and shifting tectonic plates.

If we could head back in time 56 million years and spend a few weeks botanizing in the temperate forests of the Northern Hemisphere, at the boundary between the Paleocene and the Eocene, we would be hard-pressed to find any oaks. We would find alligators and giant tortoises on Ellesmere Island, across from the northwest coast of Greenland. We would roam through flowering-plant-dominated forests whose diversity approached the plant diversity we might find in the modern forests of the southeastern United States. We would encounter a diversity of Fagales, lineages spreading across the Northern Hemisphere that would eventually give rise to walnuts, birches, sweet gales, beeches, chestnuts, chinkapins, and oaks.

The oaks themselves, however, were so few in number at that point that they left scant if any pollen in the mud and no acorns or leaves to be recovered by 21st-century botanists. The world was about to enter a heatwave, the Paleocene-Eocene Thermal Maximum (PETM).

Over the course of 8,000 to 10,000 years, atmospheric temperatures would spike, increasing by an average of 8 degrees C [14.4 degrees Fahrenheit] worldwide and reaching even higher levels in the Arctic. The PETM may have been triggered by a massive and protracted period of volcanic activity. Magma gurgling up through a fissure at the bottom of the North Atlantic drove a wedge between North America and Europe and poured a trillion kilograms [2.2 trillion pounds] of carbon into the atmosphere every year for several thousand years.

Rising temperatures melted corpses out of the Antarctic permafrost, and the rotting sedges, sphagnum mosses, fungi and lichens, mollusks and marsupials returned greenhouse gases — carbon dioxide and methane — to the atmosphere.

Temperatures then crashed back to their original levels within about 120,000-220,000 years. That's barely enough for a double take in geological terms: When you look at a temperature plot for the past 100 million years, the PETM looks like a fencepost driven into the hillside 56 million years ago. It goes straight up and almost straight back down.

The effects were dramatic. The PETM drove 30%-50% of deep-ocean-bottom foraminifera — single-celled organisms that populate the seas, eating plankton and detritus, feeding small fish and marine snails — extinct. Mammals, lizards, and turtles migrated widely across the continents in response to the changing climates, traveling between northern land bridges that would become too cold for regular travel by most of these species in the late Eocene.

In northern South America, tropical forests were flooded with new flowering plants: palms, grasses, and the Bean Family (Fabaceae) all increased in diversity in the Eocene, and the Spurge Family — Euphorbiaceae, a global family that numbers about 6,500 species today — showed up in northern South America for the first time during the PETM.

The first oak fossils

Insect herbivores, particularly leaf miners and surface feeders, increased in abundance and became more specialized. Plants raced across the landscape: in Bighorn Basin, Wyoming, at least 22 species were extirpated at the onset of the PETM, only to return after the event was over. Some of these sojourners migrated an estimated 1,000 kilometers [600 miles].

The first fossil oaks we know of appear in this uncertain world, along what is now a hiking trail running south of the Church of Saint Pankraz in Oberndorf, Austria. Fifty-six million years ago, this area of Europe was dissected into islands and peninsulas, which were warmed by the ocean.

What is now Saint Pankraz lay beneath shallow water at the edge of the sea. It became a repository for pollen from adjacent forests, deposited alongside oceanic plankton and dinoflagellates. The forest growing in the area was a mosaic of subtropical and temperate species, including members of the Restionaceae, a grass-like family that today is limited to the Southern Hemisphere tropics; Eotrigonobalanus, an extinct genus of the Beech Family that formerly ranged across eastern North America and Europe; and relatives of today's Cashew Family, Mallow Family, and the pantropical Sapotaceae.

The world was entering the last days of the nearly global tropics. For 4 million years after temperatures retreated from the PETM, the climate continued to warm. By 52 million years ago, the world hit the highest temperatures since the demise of the dinosaurs. This period of warmth is called the Early Eocene Climatic Optimum.

If the PETM is like a fencepost driven into the temperature hillside, the Early Eocene Climatic Optimum is like the crest of the hill. Forests of tropical species growing alongside genera of the temperate forest — maples, elms, walnuts, birches, cherries, and eventually oaks — spread across the high Arctic. The long winter nights favored species that could go dormant for months at a time. Deciduous forests spread across upland sites that are now permafrost and boreal forest.

The climate was perched at the top of a long slide down to the Anthropocene, where we find ourselves today. Oaks were pioneers in what would become the largely temperate Northern Hemisphere.

The oaks were not born at a particular moment or in a particular place. Instead, somewhere during or before the PETM, a population of woody plants gradually became the oaks. Each seedling in this lineage looked like the trees that produced it. Had we been there to witness the evolution of that ancestral population, we could at no point have said, "There were no oaks yesterday, but today there are."

Related: Where did the 1st seeds come from?

We ended up with oaks by the steady work of natural selection acting on variable tree populations over long periods of time. This lineage of individuals and populations slowly becoming the oaks is called the stem of the oak clade. It is represented on the Tree of Life by a single line.

The population of trees that deposited the St. Pankraz pollen may represent a sprig sprouting from that stem or one that sprouted very near the crown of the oaks. In either case, the St. Pankraz pollen is, for now, our best bet about how old the oaks are. Oaks probably go back at least a little longer than these fossils, older than the PETM: fossils are hard to find, so it's reasonable to suspect that we may have missed some older ones. But these fossils provide us a landmark by which to date the oak tree of life.

The first speciation event we know of in oaks likely occurred within 8 million years of the St. Pankraz oak fossil. It split the oaks into two lineages: one that is today limited to Eurasia and North Africa, and one that evolved in the Americas and only later returned to Eurasia. Sister clades — which are born as sister species — can arise in separated geographic regions when their ancestral population becomes physically subdivided. A mountain range, a river, a desert, an expanse of ocean, or any other barrier between the two portions of the population keeps seeds and pollen from moving between the two new populations. Speciation and the birth of new clades often result.

The spreading Atlantic Ocean is a plausible explanation for this first oak speciation event. Magma spilling into the North Atlantic off the coast of Ireland at the beginning of the PETM added crust to the east edge of the North American (tectonic) Plate and the west edge of the Eurasian Plate. It continues to do so today, steering the continents apart at a rate of about an inch a year.

As the Atlantic grew wider, the ancestral population of all of today's oaks may have been straddling the continents of the Northern Hemisphere. If so, the ancestor of the oaks we know today was a widespread population that was cleaved in half as North America inched westward.

Reprinted with permission from Oak Origins: From Acorns to Species and the Tree of Life by Andrew L. Hipp, published by The University of Chicago Press. © 2024 by Andrew L. Hipp. All rights reserved.

Scientists have discovered that an "alien plant" first found near a Utah ghost town 55 years ago doesn't appear to be related to any currently living family or genus.

Paleontologists first found fossilized leaf specimens of the plant in 1969 and named it Othniophyton elongatum, which translates to "alien plant." At the time, they believed the extinct species could be related to ginseng.

A more recent analysis, however, has challenged that hypothesis. Steven Manchester, curator of paleobotany at the Florida Museum of Natural History and Utah fossil expert, came across an unidentified plant fossil while visiting the University of California, Berkeley paleobotany collection. This plant fossil was well preserved, and had come from the same area as the alien plant leaves.

Manchester's research team analyzed the fossils and concluded they were from the same plant species, according to their study published Nov. 9 in the journal Annals of Botany.

Both fossil specimens were excavated from the Green River Formation in eastern Utah, near the former town of Rainbow. Around 47 million years ago, when the plants lived, the region was a huge lake ecosystem near active volcanoes. Lake sediment and volcanic ash slowed decomposition in fish, reptile, bird and plant remains, enabling some to be extremely well preserved.

Related: Where did the 1st seeds come from?

The researchers analyzed both fossils' physical features, and searched for living plant families that could be similar. Unlike the 1969 find, the specimen at UC Berkeley had leaves, flowers and fruits attached, which looked very different from those of plants related to ginseng. In fact, the researchers couldn't match the fossils to any of the over 400 families of flowering plants living today, and extinct families.

When scientists studied the original fossils in 1969, they were working only with leaves, not with flowers, fruits or branches; based on the arrangement of the leaves' vein patterns, they theorized the leaf structure could be similar to that of plants in the ginseng family. With the detail provided by the newer fossil, the researchers had a better picture of what the plant would have looked like and discounted the ginseng connection, but still couldn't pinpoint the plant's family.

A few years later, the Florida Museum of Natural History had access to new microscopy and artificial intelligence technology that enabled even more detailed viewing of the plant fossils. Micro-impressions of small, developing seeds were visible in the fossil's fruits. The research team could also see stamens — flowers' male reproductive organs — which in most plant species detach after fertilization.

"Usually, stamens will fall away as the fruit develops. And this thing seems unusual in that it's retaining the stamens at the time it has mature fruits with seeds ready to disperse. We haven't seen that in anything modern," Manchester said in a statement.

Comparing these traits to extinct families didn't result in any matches either, but this isn't the only species from the Green River Formation that has stumped scientists. This region has previously produced other plant fossils, like Bonanzacarpum fruit and Palibinia leaves, that have surprised scientists and ultimately led to the discovery of extinct groups.