Plants and Trees Communicate Through an Unseen Web

Plants can even ward off invaders through “Earth’s natural internet.”


Forest with trees and undergrowth.
Your typical forest is doing more than meets the eye.

Ever borrow something from a friend or neighbor? You gossip while there too, right? Perhaps even align yourselves against a common enemy. The “Wood wide web,” can do all of this for plants. Fungi are made up of tiny threads called mycelium. These travel underground, connecting the roots of different plants in an area, even different species, together, allowing them to communicate and so much more. Some researchers say the trees of the forest and the mushrooms we find growing next to them are so interconnected, that it is hard for them to see trees as individual entities any longer.

Though this may sound like news to some, indications of “Earth’s natural internet” go back to the 19th century, beginning with German biologist Albert Bernard Frank. He is the first to discover a symbiotic relationship between fungal colonies and the roots of plants. Frank created the term "mycorrhiza" to describe this symbiosis. Today we know that approximately 90% of all land-based plants are connected through what is called the mycorrhizal network.

Fungi and trees are so interconnected, some scientists believes they should not be viewed as separate organisms.

Since the 1960s we’ve known that fungi aid in plant growth. Since then, scientists have learned that they also help plants locate water and provide certain nutrients through mycelia strands around their roots. The fungal networks protect plants from infection too, by providing protective compounds, stored in the roots, which are triggered should the plant be attacked. This phenomenon, called “priming,” makes the immune system of the plant far more effective. In return, plants feed their fungi carbohydrates on a consistent basis.

Besides defense, it also serves as a communication network, connecting even to plants which are far away. Paul Stamets first had the idea of such a network in the 1970s, while studying fungi under an electron microscope. He found that there were startling similarities between the precursor to the internet, the US defense department’s ARPANET, and these fungal networks. Yet, it took decades of research to uncover the sheer breadth of the phenomenon. Other scientists have since likened it to an animal’s nervous system.

In 1983, two studies proved that poplars and sugar maple trees warn each other about worrisome insects. When one tree becomes infested, it warns others who begin producing anti-insect chemicals, to protect against attack. These signals are sent through the air. Even then, the splinter group of scientists studying this phenomenon were for decades waved away. Since the late 90’s however, such researchers have proven that trees transfer carbon, nitrogen, phosphorus, and other nutrients, back and forth via mycelia. Today, though only a scant few study it, the phenomenon is no longer in doubt.

Mycorrhizal threads. Photo by The Alpha Wolf CC-BY-SA-3.0 via Wikimedia Commons

Suzanne Simard of the University of British Columbia discovered nutrient exchanges between Douglas fir trees and paper birches. She believes it goes even farther than this. Simard says that small, younger trees are helped through the network by larger, older ones. Without such aid, she said, seedlings wouldn’t stand a chance. Simard found in one study that food strapped seedlings stuck in the shade received carbon from nearby trees to help them along.

Of course, Simard isn’t suggesting that plants have consciousness or that they are individuals in any sense. But they are interacting and helping one another survive. Other experts warn that although we are aware of such exchanges, to what extent they occur remains unclear.

In 2010, Ren Sen Zeng, a researcher at South China Agricultural University, proved that plants communicate through the mycelia network. Zeng and colleagues found that when infected with blight, tomato plants release a chemical signal to warn others nearby. These plants also “eavesdrop” on neighbors, to determine when to build up their defenses against oncoming pathogens. A 2013 study found that broad beans also signaled neighbors through the fungal network, this time due to an aphid infestation. But not all interactions are helpful. There is a dark side to the mycorrhizal network, too.

Mycelium. Photo by Rob Hille [CC BY-SA 3.0)], via Wikimedia Commons

A phantom orchid for instance cannot produce its own energy. Instead, it steals carbon from trees close by in order to survive, accessing the nutrients via the mycelia threads connecting them. Other orchids, known as “mixotrophs” can photosynthesize, but steal from others when it suits them. Plants also at times compete for resources such as light and water. When this occurs, some release toxins to slow their competitors encroachment in a process is called, "allelopathy." Certain species of Eucalyptus, , American sycamores, acacias, and sugarberries are known to do this. The chemicals they release travel the network and block nearby plants from establishing themselves, or reduce the number of friendly microbes at their roots to impede their opponent’s growth.

Some experts theorize that animals may be taking advantage of the fungal network for their own ends. The same chemicals that bring helpful fungi and bacteria to a plant’s roots might also signal worms and other harmful organisms looking for a snack. But this theory to date hasn’t been tested. Some say the fungal network gives us another example of how interconnected all life on Earth actually is and how each organism depends on another and in turn is depended upon. It also makes us question whether such actions constitute behavior, and what motivated plants to link up to begin with, and for fungi to lend a hand in the endeavor.

To learn more about how plants communicate click here: 

A landslide is imminent and so is its tsunami

An open letter predicts that a massive wall of rock is about to plunge into Barry Arm Fjord in Alaska.

Image source: Christian Zimmerman/USGS/Big Think
Surprising Science
  • A remote area visited by tourists and cruises, and home to fishing villages, is about to be visited by a devastating tsunami.
  • A wall of rock exposed by a receding glacier is about crash into the waters below.
  • Glaciers hold such areas together — and when they're gone, bad stuff can be left behind.

The Barry Glacier gives its name to Alaska's Barry Arm Fjord, and a new open letter forecasts trouble ahead.

Thanks to global warming, the glacier has been retreating, so far removing two-thirds of its support for a steep mile-long slope, or scarp, containing perhaps 500 million cubic meters of material. (Think the Hoover Dam times several hundred.) The slope has been moving slowly since 1957, but scientists say it's become an avalanche waiting to happen, maybe within the next year, and likely within 20. When it does come crashing down into the fjord, it could set in motion a frightening tsunami overwhelming the fjord's normally peaceful waters .

"It could happen anytime, but the risk just goes way up as this glacier recedes," says hydrologist Anna Liljedahl of Woods Hole, one of the signatories to the letter.

The Barry Arm Fjord

Camping on the fjord's Black Sand Beach

Image source: Matt Zimmerman

The Barry Arm Fjord is a stretch of water between the Harriman Fjord and the Port Wills Fjord, located at the northwest corner of the well-known Prince William Sound. It's a beautiful area, home to a few hundred people supporting the local fishing industry, and it's also a popular destination for tourists — its Black Sand Beach is one of Alaska's most scenic — and cruise ships.

Not Alaska’s first watery rodeo, but likely the biggest

Image source:

There have been at least two similar events in the state's recent history, though not on such a massive scale. On July 9, 1958, an earthquake nearby caused 40 million cubic yards of rock to suddenly slide 2,000 feet down into Lituya Bay, producing a tsunami whose peak waves reportedly reached 1,720 feet in height. By the time the wall of water reached the mouth of the bay, it was still 75 feet high. At Taan Fjord in 2015, a landslide caused a tsunami that crested at 600 feet. Both of these events thankfully occurred in sparsely populated areas, so few fatalities occurred.

The Barry Arm event will be larger than either of these by far.

"This is an enormous slope — the mass that could fail weighs over a billion tonnes," said geologist Dave Petley, speaking to Earther. "The internal structure of that rock mass, which will determine whether it collapses, is very complex. At the moment we don't know enough about it to be able to forecast its future behavior."

Outside of Alaska, on the west coast of Greenland, a landslide-produced tsunami towered 300 feet high, obliterating a fishing village in its path.

What the letter predicts for Barry Arm Fjord

Moving slowly at first...

Image source:

"The effects would be especially severe near where the landslide enters the water at the head of Barry Arm. Additionally, areas of shallow water, or low-lying land near the shore, would be in danger even further from the source. A minor failure may not produce significant impacts beyond the inner parts of the fiord, while a complete failure could be destructive throughout Barry Arm, Harriman Fiord, and parts of Port Wells. Our initial results show complex impacts further from the landslide than Barry Arm, with over 30 foot waves in some distant bays, including Whittier."

The discovery of the impeding landslide began with an observation by the sister of geologist Hig Higman of Ground Truth, an organization in Seldovia, Alaska. Artist Valisa Higman was vacationing in the area and sent her brother some photos of worrying fractures she noticed in the slope, taken while she was on a boat cruising the fjord.

Higman confirmed his sister's hunch via available satellite imagery and, digging deeper, found that between 2009 and 2015 the slope had moved 600 feet downhill, leaving a prominent scar.

Ohio State's Chunli Dai unearthed a connection between the movement and the receding of the Barry Glacier. Comparison of the Barry Arm slope with other similar areas, combined with computer modeling of the possible resulting tsunamis, led to the publication of the group's letter.

While the full group of signatories from 14 organizations and institutions has only been working on the situation for a month, the implications were immediately clear. The signers include experts from Ohio State University, the University of Southern California, and the Anchorage and Fairbanks campuses of the University of Alaska.

Once informed of the open letter's contents, the Alaska's Department of Natural Resources immediately released a warning that "an increasingly likely landslide could generate a wave with devastating effects on fishermen and recreationalists."

How do you prepare for something like this?

Image source:

The obvious question is what can be done to prepare for the landslide and tsunami? For one thing, there's more to understand about the upcoming event, and the researchers lay out their plan in the letter:

"To inform and refine hazard mitigation efforts, we would like to pursue several lines of investigation: Detect changes in the slope that might forewarn of a landslide, better understand what could trigger a landslide, and refine tsunami model projections. By mapping the landslide and nearby terrain, both above and below sea level, we can more accurately determine the basic physical dimensions of the landslide. This can be paired with GPS and seismic measurements made over time to see how the slope responds to changes in the glacier and to events like rainstorms and earthquakes. Field and satellite data can support near-real time hazard monitoring, while computer models of landslide and tsunami scenarios can help identify specific places that are most at risk."

In the letter, the authors reached out to those living in and visiting the area, asking, "What specific questions are most important to you?" and "What could be done to reduce the danger to people who want to visit or work in Barry Arm?" They also invited locals to let them know about any changes, including even small rock-falls and landslides.

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Credit: Pixabay
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