A Paean to Skepticism I: Where the “Wood-Wide Web” Narrative Went Wrong

This is a great story of the science-journalism interface and how things can go wrong, even when everyone has the best of intentions. What I like is that the scientists admit to their own biases and perhaps a bit of overenthusiasm.. Skepticism by all of us.. is so important! This is the theme of the next three posts.

A compelling story about how forest fungal networks communicate has garnered much public interest. Is any of it true?


Over the past few years, a fascinating narrative about forests and fungi has captured the public imagination. It holds that the roots of neighboring trees can be connected by fungal filaments, forming massive underground networks that can span entire forests — a so-called wood-wide web. Through this web, the story goes, trees share carbon, water, and other nutrients, and even send chemical warnings of dangers such as insect attacks. The narrative — recounted in books, podcasts, TV series, documentaries, and news articles — has prompted some experts to rethink not only forest management but the relationships between self-interest and altruism in human society.

But is any of it true?

The three of us have studied forest fungi for our whole careers, and even we were surprised by some of the more extraordinary claims surfacing in the media about the wood-wide web. Thinking we had missed something, we thoroughly reviewed 26 field studies, including several of our own, that looked at the role fungal networks play in resource transfer in forests. What we found shows how easily confirmation bias, unchecked claims, and credulous news reporting can, over time, distort research findings beyond recognition. It should serve as a cautionary tale for scientists and journalists alike.

First, let’s be clear: Fungi do grow inside and on tree roots, forming a symbiosis called a mycorrhiza, or fungus-root. Mycorrhizae are essential for the normal growth of trees. Among other things, the fungi can take up from the soil, and transfer to the tree, nutrients that roots could not otherwise access. In return, fungi receive from the roots sugars they need to grow.

As fungal filaments spread out through forest soil, they will often, at least temporarily, physically connect the roots of two neighboring trees. The resulting system of interconnected tree roots is called a common mycorrhizal network, or CMN.

Years ago, when the early experiments were being done on forest fungi, some of us — the authors of this essay included — simply got caught up in the excitement of a new idea.

When people speak of the wood-wide web, they are generally referring to CMNs. But there’s very little that scientists can say with certainty about how, and to what extent, trees interact via CMNs. Unfortunately, that hasn’t prevented the emergence of wildly speculative claims, often with little or no experimental evidence to back them up.

One common assertion is that seedlings benefit from being connected to mature trees via CMNs. However, across the 28 experiments that directly tackled that question, the answer varied depending on the trees’ species, and on when, where, and in what type of soil the seedling is planted. In other words, there is no consensus. Allowed to form CMNs with larger trees, some seedlings seem to perform better, others worse, and still others seem to behave no differently at all. Field experiments designed to allow roots of trees and seedlings to intermingle — as they would in natural forest conditions — cast still more doubt on the seedling hypothesis: In only 18 percent of those studies were the positive effects of CMNs strong enough to overcome the negative effects of root interactions. To say that seedlings generally grow or survive better when connected to CMNs is to make a generalization that simply isn’t supported by the published research.

Other widely reported claims — that trees use CMNs to signal danger, to recognize offspring, or to share nutrients with other trees — are based on similarly thin or misinterpreted evidence. How did such a weakly sourced narrative take such a strong grip on the public imagination?

We scientists shoulder some of the blame. We’re human. Years ago, when the early experiments were being done on forest fungi, some of us — the authors of this essay included — simply got caught up in the excitement of a new idea.

One of us (Jones) was involved in the first major field study on CMNs, published more than 25 years ago. That study found evidence of net carbon transfer between seedlings of two different species, and it posited that most of the carbon was transported through CMNs, while downplaying other possible explanations. This is what’s known as “confirmation bias,” and it is an easy trap to fall into. As hard as it is to admit, it was only due to our skepticism of the recent extraordinary claims about the wood-wide web that we looked back and saw the bias in our own work.

Over decades, these and other distortions have propagated in the academic literature on CMNs, steering the scientific discourse further and further away from reality, similar to a game of “telephone.” In our review, we found that the results of older, influential field studies of CMNs have been increasingly misrepresented by the newer papers that cite them. Among peer reviewed papers published in 2022, fewer than half the statements made about the original field studies could be considered accurate. A 2009 study that used genetic techniques to map the distribution of mycorrhizal fungi, for instance, is now frequently cited as evidence that trees transfer nutrients to one another through CMNs — even though that study did not actually investigate nutrient transfer. In addition, alternative hypotheses provided by the original authors were typically not mentioned in the newer studies.

As these biases have spilled over into the media, the narrative has caught fire. And no wonder: If scientists themselves could be seduced by potentially sensational findings, it is not surprising that the media could too.

Among peer reviewed papers published in 2022, fewer than half the statements made about the original field studies could be considered accurate.

Journalists told emotional, persuasive, and seductive stories about the wood-wide web, amplifying the speculations of a few scientists through powerful storytelling. Writers imbued trees with human qualities, portraying them as conscious actors using fungi to serve their needs. Fantasy moved to the foreground, facts to the back. In an odd kind of mutual reinforcement, the media blitz may have convinced experts in other subfields of ecology that the claims about CMNs were well-founded.

The episode underscores how important it is for journalists to seek out a broad range of expert opinions, and to challenge us scientists when our assertions aren’t clearly backed up by rigorous research. By directly asking scientists questions such as “What other phenomena could explain your results?” and “How many other studies support this hypothesis?” journalists may be able to better understand and convey some of the uncertainty around scientific conclusions. The best science writing can capture the hearts and minds of the public, but it must be true to the evidence and the scientific process. If not, the consequences can be far-reaching, affecting policy decisions that impact real people.

There are many captivating and scientifically well-grounded stories we can tell about fungi in forests — and we should. Mycorrhizal fungi underlie many of our favorite edible mushrooms, including truffles, chanterelles, and porcinis. And some herbs in the understories of forests, rather than photosynthesizing sugars like a normal plant, use CMNs to connect to trees and steal their sugars. Forests are fascinating places, marked by a rich diversity of interactions between plants, animals, and microbes. The stories are endless. We just have to tell them with care.

Melanie Jones is a professor in the Biology Department at the University of British Columbia’s Okanagan campus. She and her students have been studying mycorrhizal fungal communities in forests, clearcuts, and wildfire sites in British Columbia for 35 years.

Jason Hoeksema is a professor in the Department of Biology at the University of Mississippi. His research addresses a diversity of questions regarding the ecological and evolutionary consequences of species interactions on populations, communities, and ecosystems.

Justine Karst is an associate professor in the Department of Renewable Resources at the University of Alberta. She has been studying the mycorrhizal ecology of forests for 20 years.


28 thoughts on “A Paean to Skepticism I: Where the “Wood-Wide Web” Narrative Went Wrong”

  1. Two articles from Scientific American:

    ‘Mother Trees’ Are Intelligent: They Learn and Remember
    And ecologist Suzanne Simard says they need our help to survive

    The Idea That Trees Talk to Cooperate Is Misleading
    It’s a romantic notion, but pretending they’re like humans could actually harm the cause of conservation

  2. Some thoughts, for what they’re worth. This has deep roots (pun intended):

    – There is a recurrent (like, century or more) tendency to want to see things as emergent superorganisms despite no great evidence for this (see, for one, the review of understandings of ecosystem dynamics in history, Forest Stand Dynamics, Chadwick and Oliver, 2nd Edition, page 4, citing many)

    – “superorganism” concepts are subtly eked out of, or lurk in the background of any data that shows cooperation or more “holistic” interactions, nature slightly less red in tooth and claw.

    – Altruism in evolution is real but often taken too enthusiastically to ground some kind of grand ethical project (interestingly, some of the most nuanced discussions here come from theologians, the brits Sarah Coakley and Conor Cunningham come to mind).

    – It’s not uncommon in the environmental community to see quasi-mystical approaches to nature which is fine but not really useful for public policy. Giving these feelings a scientific gloss is likely a reason for these kinds of findings proving popular beyond their merits (think, uncritical endorsements of holism, that kind of thing)

    – The marketing and ted-talk nature of discourse lends itself to this and rewards otherwise totally legitimate scientists when they make “cute” “pop” headline grabbing findings (see for instance Jesse Singal’s book “The Quick Fix, on this phenomenon in social psychology, and even the links to SciAm above show this kind of phenomenon)

    • A. thanks for this and your usual deep philosophical insights. I remember when the ecosystem concept was gaining hold. There are folks (myself included) that see random post glacial assemblages of species that robustly moved North to reclaim the land and adapted to each other. Then there are those for whom “ecosystems” are finely tuned more or less static perfections that humans have disrupted (but not usually Native Americans or other Indigenous folks). Putting systems together (math envy..so biologists use the latest thinking inherited from those disciplines more noble) with a form of holism was a stroke of brilliance. Just way cooler, in so many ways, than biology as “stamp collecting”. you might enjoy this op-ed in Science by Ernst Mayr. https://www.science.org/doi/10.1126/science.7079730

      • Thanks Sharon! . And for the comments below of course. Excited to read the mayr article. No intention to “attack” the more holisitic positions altogether (I dislike military metaphors and their ubiquity in discourse and policy). It’s more of something that I’d roughly divide into “vague” holism and “exacting” holism, and your comment captures some of that. Euroamerican modernity did indeed disrupt, but what it disrupted were assemblages in ways that have resulted in novel, not entirely good, not entirely bad changes in those assemblages. And indigenous cultures disrupted as well, but often more delicately, at more sustainable scales, hence the value-added of TEK-type information. I’m hopeful that a more “exacting” holism can result from this kind of synthesis. Whereas what I’d call “vague” holism is the type of thinking that reflexively assumes that fixates on reverting to an imagined perfect past (whether in types of disturbance or lack thereof, and typically also in terms of human population and distribution).

        • I’d only add that some see the Enlightenment as the triumph of reason over superstition.. old-fangled mysticism of the Eckhart and Hildegard strains or the Baal Shem Tov. And yet beliefs in various things, angels for example are still prominent e.g. from ARDA. The river may be below the surface but has never dried up. As for me, I always say “the so-called Enlightenment” as my world was never disenchanted.

  3. Back in the day before Forestry School (Mid 70’s) I attended Lane Community College in Eugene OR, had a Freeman Rowe, 1930-2020, Biology & Fungi class instructor, became my friend, Founder and Father of the Cascade Mycological Society, tell me when asked about this subject, called it “a bunch of unproven bunk”. Last time I saw him alive in Baja Sur in the late 90’s, he said even though considerable research had taken place, nothing had been proven to change his mind.

  4. Sharon, the same statements can be made about spotted owl “research” that led to its listing in 1990. As an aside, you are doing a terrific job. Our mutual friend, Rich Stem, has nice things to say about you! Best wishes, JIm

    • Yeah, the only difference is that the spotted owl story is true, or at least no court has been convinced otherwise.

  5. It’s so messed up the way everyone is ignoring the actual scientific observations of tracers put in the soil and the method by which they end up in the trees and vice versa… That’s the most valid part of the research that’s been done and no one is challenging those details directly, just challenging all the ideas and dot-connecting that was inspired from those primary observations.

    And because there’s so many variables in a forest ecosystem you can always find a site that will discredit the findings from another site, especially if the sites have been previously destroyed by logging in the recent past.

    Still intact primary forests in British Columbia where much of this research has been done is so much different and more complex than previously trashed and recovering forests elsewhere. What’s more old growth forest soils that far north are entirely different than soils further south.

    When I first studied old growth in British Columbia in the Elaho Valley Wilderness I was astonished by how extreme the amount or roots were in relation to the amount of available soil compared to places further south, which had way less roots and way more soil. Just digging a hole to take a poop in BC was near impossible because of the root fiber density…

    And speaking of poop, this backlash is a classic example of how when tree farming / industrial forestry gets discredited with valid observations that need a great deal more study, those who’s career depends on timber industry dogma will find ways to nit-pick and discredit the often exaggerated conclusions rather than the more conservative science-based observations. Yet another smear campaign opposed to efforts to better understanding the science of the rhizosphere because no matter how much new science there is, the 1970’s dogma of monocrop rapid rotation tree farming is supposed to be the only truth that matter. So sick of the stench of this BS!

    • Is your house made of mud, concrete, or some other non-timber product? Do you enjoy it?
      Where did the lithium batteries in your e-car come from?


      Cue “Your Anonymous and scared and I won’t address any of your points or talk in good faith or admit anything I say might have a logical, accurate, counterpoint that overrides it” attack.

      • Lol… Why is the Smokey Wire Anon person always so scared of people knowing their true identity? A respectable website/person wouldn’t accept these types of faceless comments!

        Not only do you cowardly NOT use your real name, which confirms your bias quite well all by itself. But more to the point the “you live in a wooden house” analogy is just as stupid as people like you also once telling African-American slaves that their desire for freedom is absurd because they don’t live in world where slaves are free.

        As in, if you can’t give anybody any other more enduring options for structures to live in but wood and force centuries of forest liquidation in a brief number of decades by way of land theft, by way of genocide, by way of no concern for future generation as the only option solely for profit…

        As in, it’s clear that your lack of a moral compass and your greedy-corrupt ambitions you were indoctrinated into destroyed the land your ancestors once lived on and the only way to further your/their immoral agenda is with mass murder of anyone who doesn’t destroy their land so you steal their land and prove to them that your corrupted mind and soulless heart is worth being worshiped because you do genocide and ecocide better than them…. Truly the antithesis of what humanity truly is and truly exists for.

        And yes, I’ll admit, I’d also be an Anon coward if I was dumbly pushing your indoctrinated brain-dead agenda too!

        Many also refer to this planet killing dogma of yours as the disease of gaslighting, or rather the way that Christianity exploits humans in despicable ways by telling them that we murdered their savior because they are horrible and awful and they must always do as they’re told or we’ll punish them forever for the sins they did that their savior had to die for.

        • Deane, there are many Anonymous people on this website. In fact, Anonymous The Philosophically Inclined is one of my favorite characters on this site :).

          I don’t know if you think it’s OK to say mean things because you use your real name (going after Christianity, calling someone brain-dead etc.) but it’s not. You are probably one of the worst in terms of stating mean things about others over and over.

          “A respectable website/person wouldn’t accept these types of faceless comments!”

          I guess we’re not respectable, then, according to your criteria. That’s OK. Again, maybe your pointing out Anon’s comments will get you less to focus on the source of the comment (Anon, in this case) than the content (which is much more mild than the comments you regularly post).

      • Sharon – I’d like to highlight this as an example of something I think we should screen out from anonymous posters. We get lots of good information from many (or at least I assume it’s many) anonymous posters, but this is just a personal attack that contributes nothing. If personal attacks require a name, we’d probably see them less often (and then we’d not have to read responses like Deane’s either).

        • Deane has done nothing but write personal attacks, or agenda-driven attacks, especially based on his experiences back int eh 80/90’s, since he started commenting here. He never acknowledges competing science, or at best disparages it.
          I am Anon because the reality of the world we live in today, as someone in the midst of my career in natural resources at an unnamed government entity, is that anyone could see my name on this blog, which has a wide range of readership, and come for me. And the reality is, senior staff don’t stick up for low level staff, they just pile on us and blame us, when we point things out here.

          I have constantly tried to argue in good faith on Smokey Wire, and repeatedly seen my good faith arguments referred to as “a troll”, a “timber beast”, an “anonymous hack” etc. Deane has never contributed anything besides personal, agenda driven, biased attacks and diatribes here, and when I call him out, I am the one to be blamed and punished? I’m sorry, but as a millennial, I still rent a house and live paycheck to paycheck while working 45-50 hours a week in my chosen field, and don’t take lightly to someone trying to recreate their 1990-ish summer of happiness and ignoring science because it is legit and hurts their feelings.

          Have you ever noticed that all of Deane’s comments are the long winded diatribes that have little to nothing to do with the original post, nothing to do with science or policy, and everything to do with feelings and an agenda? But….I pointed out his own confirmation bias and issues, and now I am the bad person? Ok.

          Just remember, those of us not retired, are scared to use our own name because we have seen what happens to those of us in agencies, not Universities or retired, and we all would like to own a couple acres and a home and a pension someday as well.

          • I was in the same situation, and was once reported to the Chief of the Forest Service. Luckily, the Chief was in the middle of opposing the lies and misinformation about the Agency, but I did have to give my supervisor a ‘heads up’. I was advised to ‘be careful’ and not make the Forest Service look bad. At that point, I chose to go with an alias. Yes, some activists who oppose the Forest Service have no problem with ending someone’s career, if they can.

          • My point was that anonymous trolling can be done lots of places, but this shouldn’t be one of them. I fully understand the risks of being a current employee (having been there). I am only suggesting that the price of anonymity here should be less freedom to attack others with nonfactual posts. I’d add that having a name would let someone consider the “cumulative effects” of repeated comments. I’ve called out Deane before, but I’ve actually found among Deane’s “feelings and agenda” some things that appear to be facts, some of which are interesting. In your case (assuming you are the same “Anon” as before), you’ve probably made your point about Deane plenty of times, and while that may be entertaining to some, it’s mostly a waste of time.

            • I do think Deane would be more effective if he dropped that extremist rhetoric. He does have valid considerations, otherwise, even if some don’t agree, or even accept.

              OTOH, the extreme right-wing rhetoric is worse. We’ve been somewhat sheltered here from QAnon and ‘Deep State’ stories, but some seem to truly believe such conspiracy ideas. disbelief of science, in general, fuels the lunacy.

              • Over several years I can recall a couple of vituperative anti-conservation comments. But they are extremely rare. And I don’t recall much vituperation from militants on the other side either. Almost everyone is civil.

          • The moderation on this forum is rather lax. The biochar forum removed Deane after he made similar remarks. Why does this forum tolerate them?

            • The moderation here is done by a few different folks..so.
              For me, I am hopeful that Deane will be influenced by the rest of us to moderate his negative comments about us. After all, there are others among us who are sometime crotchety and it would be time-consuming to critique/delete each negative comment.. about Ds or Rs or ranchers or enviros or.. even about other TSWites.
              But perhaps that’s easy for me to say as I don’t read Deane’s comments because the bad parts outweigh the good parts, or whatever useful info he has to convey. I guess I tend to err on the side of hospitality.

              • There are always nuggets of truth – but for me the bad parts make me want to totally avoid this forum – that part gets really tiresome – I look to this forum for some meaningful and factual discussion, not attacks and name-calling. We are all passionate about the topics on this forum or we wouldn’t be here, but we need to be tough on problems go easy on people.

        • Jon, considering the fact that Deanne regularly accuses anyone who disagrees with her of being a shill for the timber industry, I don’t think names are the answer to ad hominem attacks. This is a person who posted false information on a fellow poster as part of her attempts to prove this. Her comments are consistently the most personal and rude in their nature in my opinion. However, they are always entertaining in the sheer vitriol directed at the timber industry and forestry in general.

    • Sorry Deane, are you saying that the other scientists who don’t agree with Simard’s holism observations are believers in monocrop tree farming? because I don’t think they are, and I am not. In fact, many forests are not west side Dfir or hemlock forests, nor have they ever been “monocropped”. I am reminded of a Silviculture Training at Pringle Falls in the 80’s with Bruce Larson and Chad Oliver. All their models seemed to be based on light being a limiting factor. “But” I asked “what if water is the limiting factor?” and they replied that that’s not how their models worked.
      Here’s how I see it… due to trees growing faster on the west side, and the timber industry, many forest scientists were located there. So places like OSU UW and the FS R&D places associated with them gained market share in terms of forest R&D. Meanwhile places like central Oregon might have gotten a scattering of scientists and R&D $. Somehow this has translated into much of forest policy being filtered by the framing of mesic forests. Simard’s work is in some ways just another example of this. IMHO.

  6. Skepticism is good, as is skepticism of the skepticism. A rebuttal by other scientists, say Suzanne Simard, would be good to include.

    I agree, the “wood wide web” is anthropomorphizing an ecological phenomena, but it also makes it appealing and understandable to those who are not scientists, like most of the people living in North America. Most scientists are terrible at communicating in a way that is both understandable and interesting to the general public.

    I think we all suffer from confirmation bias to some degree and presenting only one side of a discussion is, of course, promoting confirmation bias.

    Regardless, I found this opinion piece to be excellent writing; now let’s hear the rebuttal.

    • Mike, I was also reading this week about this bison calf at Yellowstone https://cowboystatedaily.com/2023/05/23/humans-do-it-again-baby-bison-euthanized-after-tourist-tries-to-rescue-it/
      Anthropomorphizing nature can also lead to bad outcomes in this case. And there’s also the issue of whether anthropomorphizing is actually true or not- if not does scientists not telling the truth reduce folks’ trust in scientists?
      I agree that skepticism about skepticism is good, even recursive skepticism as it approaches infinity! but all this reminds me of a Biodiversity Workshop in the 80’s I think. Jerry Franklin said something about genetics we considered to be wrong. So we geneticists went up to him after the talk and pointed this out. He said “well geneticist X told me that, you need to get together”. But of course there is not much of a mechanism within the scientific community to do that. Disagreeing papers often don’t help the rest of us understand the disagreements.

      • Sharon, I think the bison calf at Yellowstone event was a case of human sympathy leading to an inappropriate and irresponsible act. People have been doing these things for a long, long time, but probably even more so with the popularity of videos shared on social media of people saving animals. I read an article that said many of these animals in distress rescues are staged, but I can’t verify if that is true.

        It can be argued that anthropomorphizing by its very nature is untrue. But, to your point, yes I would agree that anthropomorphizing a scientific principle that is known to be untrue in order to promote the incorrect view would be wrong. I think in Simard’s book, she anthropomorphizes what she concluded through her research. The fact that others disagree with her conclusions doesn’t make it wrong. Not yet. Simard is currently conducting studies to answer some of the questions raised by other scientists. Science journals have long carried back and forth disagreements between scientists. My point about skepticism of skepticism is tied to that back and forth. It’s practicing good science. And just as it is good to read different takes in the mainstream media concerning different perspectives on politics, it is good to read different opinions concerning scientific topics wherever they are shared.


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