Wood Wide Web Research Articles

Mycoheterotrophy in the wood-wide web.

The prevalence and potential functions of common mycorrhizal networks, or the 'wood-wide web', resulting from the simultaneous interaction of mycorrhizal fungi and roots of different neighbouring plants have been increasingly capturing the interest of science and society, sometimes leading to hyperbole and misinterpretation. Several recent reviews conclude that popular claims regarding the widespread nature of these networks in forests and their role in the transfer of resources and information between plants lack evidence. Here we argue that mycoheterotrophic plants associated with ectomycorrhizal or arbuscular mycorrhizal fungi require resource transfer through common mycorrhizal networks and thus are natural evidence for the occurrence and function of these networks, offering a largely overlooked window into this methodologically challenging underground phenomenon. The wide evolutionary and geographic distribution of mycoheterotrophs and their interactions with a broad phylogenetic range of mycorrhizal fungi indicate that common mycorrhizal networks are prevalent, particularly in forests, and result in net carbon transfer among diverse plants through shared mycorrhizal fungi. On the basis of the available scientific evidence, we propose a continuum of carbon transfer options within common mycorrhizal networks, and we discuss how knowledge on the biology of mycoheterotrophic plants can be instrumental for the study of mycorrhizal-mediated transfers between plants.

The fungal grid: Fungal communication via electrical signals has inspired the hypothesis of a Wood Wide Web of plants and fungi: Fungal communication via electrical signals has inspired the hypothesis of a Wood Wide Web of plants and fungi.

The observation that soil-dwelling fungi seem to exchange information via electrical impulses has raised new interest about their interactions with plants and their ecological significance.

Exploring the Complex underground social networks between Plants and Mycorrhizal Fungi known as the Wood Wide Web

Mycorrhizal fungi form symbiotic relationships with plant roots, connecting multiple plants through underground networks. This biologically based “wood wide web” facilitates resource transfers between plants and is hypothesized to act as an underground communication system. We explored mycorrhizal network dynamics in sub-tropical forests of northern Pakistan. Using isotopic tracing, DNA sequencing, and root imaging, we found mycorrhizal fungal networks transferred carbon, nitrogen, and phosphorus between trees and provided growth benefits to connected seedlings. Unexpectedly, we discovered single fungal genotypes linking trees across 2 km, demonstrating extensive network reach. Our results provide comprehensive field evidence that the World Wide Web functions as a cooperative conduit enabling plants to share resources, signaling chemicals, and defense compounds. Mycorrhizal networks appear critical for seedling establishment, kin recognition, and forest resilience. Further elucidating these complex dynamics will transform our understanding of belowground ecology and enable the application of nature’s symbiotic innovations

(T)RE(E)MEDIATION

Abstract This essay explores some of the arboreal imaginings that inform analogies between mycorrhizal and technical, or arboreal and human, infrastructural networks. Rather than embrace or dismiss the idea of a wood wide web, I interrogate this intriguing comparison with the help of a variety of natural and human scientists. In so doing I explore how technical, human, arboreal, and mycorrhizal infrastructures are linked by their participation in processes of radical tree mediation.

The global tree: Forests and the possibility of a multispecies IR

AbstractForest ecosystems are crucial to survival on Earth. This article argues that trees and forests are both vital components of a healthy Earth system and productive examples for expanding International Relations’ disciplinary boundaries. The article discusses the forest in three contexts: the global, the (post)colonial, and from the tree itself. From tree planting as a practice of social and environmental justice, to postcolonial and Indigenous science and knowledge, to the mycorrhizal ‘wood wide web’, a focus on trees, forests, and biosphere opens the possibility for a multispecies IR. Through a consideration of trees and forests in law, treaty, culture, and science at the local and global level, this article adds to a growing literature in IR that strives to bring the non-human, more-than-human, or other-than-human creatively and productively into the discipline. Foregrounding the forest's materiality and trees’ symbolic power for human cultures opens important pathways to understanding how the non-human is, and should, alter and affect global politics.

Prosthetic Symbiosis

Prosthetic Symbiosis

Searching for intelligence in the Wood Wide Web

Searching for intelligence in the Wood Wide Web

Ecological Network Aesthetics and the Wood Wide Web

Ecological Network Aesthetics and the Wood Wide Web

Intelligent Trees

Walking through a forest can be one of the most relaxing and fascinating things a person can experience. The forest is full of natural wonders, like flowing streams, decomposition, and wildlife flitting about. The first thing that pops into one’s head may be that the forest is a collection of trees spaced out haphazardly across the surface. These trees are sources of food, shelter, and other resources for all the organisms living there.Most of the knowledge science has about trees and forests comes from studying the parts above ground. After all, these are easy to get to and to observe and manipulate. Well, it turns out that trees are actually quite busy below ground, and not just in reference to taking in water and minerals through their roots. This is where the Amazon Prime documentary Intelligent Trees sheds light on the complex lives of trees taking place below ground level.It turns out that trees of the forest develop what Dr. Suzanne Simard, of the University of British Columbia, calls the “wood-wide web.” This underground network connects all the trees growing near each other by way of symbiotic mycorrhizal fungi attached to the tree roots. The fungal hyphae wrap around the roots of one tree, travel through the soil to another tree’s roots, and wrap around those as well. This network continues around the forest until all (or at least most) of the trees are connected to each other. Tree roots only spread several meters from the trunk. The mycorrhizal hyphae can spread hundreds, if not thousands of meters through the soil. The biggest, most mature trees in the forest have the most linkage. The network is also species-independent. Birch, oak, maple, beech, and fir trees can all get on the web and “talk” to each other. These trees are not competitors. They support each other.This network allows the trees to share information with each other. For example, if one tree were to become infested with a parasite, it would start to produce defensive chemicals to protect itself. Signals from the infected tree travel across the network to other trees in the area, almost immediately inducing their own production of defensive chemicals, even though they have not yet been infected. These trees are now better prepared to fight off the infestation when it arrives.Dr. Simard and her team also found out that, contrary to popular belief, trees prefer to live in crowded areas. They favor the community rather than the individual. She tested this hypothesis by growing trees close to each other and then removing some of them. She found that the loss of the surrounding trees caused the remaining trees to be deficient in certain nutrients, and they died within a period of time after the other trees were removed. She states that trees send signals in a similar fashion to how the brain sends electrical impulses around the body using nerves. The mycorrhizal hyphae conduct the electrical signals from one tree to another, letting them know what is going on in the forest.The research described in Intelligent Trees is very important in terms of tree conservation and effective forest management. Forest managers need to realize that their process of cutting down trees and then planting new ones is not very effective in maintaining a healthy forest. Pristine forests are much more biodiverse and successful than planted ones. This is because planted trees do not develop the same type of network between their roots. These planted trees have to fend for themselves, losing the benefits of the collective.Intelligent Trees would be a great addition to any life science curricula. It provides a great ecological message, saying that trees are much more sophisticated in their behaviors than originally thought and that the entire forest is connected. While the Next Generation Science Standards do not put any focus on tree biology, this film could easily be incorporated when discussing the structure and function of living things or investigating solutions to conservation. An Amazon Prime subscription or a rental fee is required to view the documentary.Attributing additional human traits to trees, Dr. Simard says that “trees do talk. What they say is let us be.” Single trees are at risk. It is only through the network that forests can survive.

Edible mycorrhizal fungi of the world: What is their role in forest sustainability, food security, biocultural conservation and climate change?

Societal Impact StatementEdible mycorrhizal fungi (EMF) have been consumed since ancestral times by humans either as food, medicine or for ceremonial use. Nowadays, they are a non‐timber forest product and a diverse genetic resource with great ecological, sociocultural, economic, medicinal and biotechnological relevance around the world. Therefore, they have a paramount role to play in meeting the United Nations global sustainable development goals 2030. EMF may promote forest sustainability, biodiversity conservation, mitigation of greenhouse gas emissions through the maintenance of forest masses, human nutrition and health, economic development, conservation of biocultural heritages, women empowerment and hunger mitigation. We provide a worldwide review of the knowledge, biodiversity, novel approaches, future challenges and perspectives in the post‐COVID era of this important genetic resource whose relevance has usually received marginal attention despite its strategic global significance.SummaryEctomycorrhizal fungi play a key role in the structure and functioning of forest ecosystems. They have a paramount importance in nutrient cycling, plant protection against pathogens and abiotic stress, and establishment of underground networks that connect trees and other plants in nature, therefore being the wood wide web, the ‘internet’ of the forests. According to our literature review, globally 970 mycorrhizal fungal species (including both mushrooms and truffles) are edible, and they have enormous relevance either as a source of subsistence in low‐income human groups around the world or as an important economic component whose international commerce is worth billions of American dollars annually. Since edible mycorrhizal fungi (EMF) are a non‐timber forest product, their sustainable use and management is crucial in order to maintain forest stands and to provide well‐being to the human communities surrounding the forested areas where they grow. In different parts of the world, different cultures have developed a traditional knowledge of EMF over millennia. Their knowledge might play an important role in food supply and food security in the future, hence contributing towards the “zero hunger” global goal. The biotechnological development of EMF has also been crucial in the establishment of plantations, or successful reforestation and ecosystem restoration, which contribute to climate change mitigation by reducing greenhouse gas emissions. Here, a worldwide review of how EMF might contribute to forest sustainability, food supply, biocultural conservation, and hunger and climate change mitigation is addressed by analysing the similarities, contrasts and challenges in all five continents.

The wisdom of the woods

When Suzanne Simard discovered the wood wide web, people were sceptical. Now she has found that trees are caring, sentient and wise, she tells Rowan Hooper

Internet de las plantas: comunicación a través de la red micorrízica

Los hongos micorrícicos se clasifican como ectomicorrizas (EM) y endomicorrizas, que incluyen micorrizas arbusculares (AM). Colonizan más del 80% de las raíces de las plantas terrestres, proporcionando nutrientes del suelo y formando una red de hifas llamada internet de las plantas (wood wide web). En esta revisión se describen las interacciones en las que están involucradas las redes de micorrizas. Desde un punto de vista práctico, las EM pueden ser más beneficiosa que la AM para el desarrollo de las plantas y la relación entre hongos y plantas está condicionada por factores externos. La investigación también mostró que el micelio puede transferir una amplia variedad de compuestos y señales entre las plantas, que pueden modificar su comportamiento para proteger la red en su conjunto. La transferencia de carbono es una herramienta importante para lograrlo y puede promover la regeneración de los bosques. Estos hallazgos enfatizan la complejidad de las relaciones en los bosques y la importancia de estudiar su dinámica para garantizar su conservación.

Listening to the Trees: Seven Words on the Coronavirus

Listening to the Trees: Seven Words on the Coronavirus Belden C. Lane (bio) For twenty-five years I’ve had a practice of praying with a 100-year-old cottonwood tree in the park across the street from my house. I call him Grandfather. As his leaves rustle in the wind in this time of crisis, I’ve imagined what he might be saying to the human community on behalf of the forests of the world. Click for larger view View full resolution Photo courtesy of Jim Taylor. 1. We’re in this together You aren’t alone. Trees neither catch nor carry the virus, but we stand alongside you nonetheless. We’re all part of a single-family, the body of Christ. We’re like the forty-seven thousand trees that make up an aspen grove in central Utah, spread over two hundred acres. What seems to be a small forest is actually a single organism. Every tree is genetically alike, sharing a common root system. That’s a good image for the entire earth community right now. It’s good to think of ourselves as integral parts of a large family unit—a superorganism. When we gracefully interact within that wider whole, new emergent behaviors—a new beauty—appears that hadn’t been there before. You see it in a swirling flock of larks or a churning school of fish. A little gesture here or there shifts the entire system in unpredictable ways. What happens out on the edge reverberates throughout the whole, changing everything. Every act of generosity and care that you exercise in this time has a greater effect than you imagine. Once you identify yourselves as part of a global household, you’ll be more sensitive to every shifting need within the system. Trees can introduce you to this vast symbiotic mystery. [End Page 137] 2. Spend time with a tree In times of fear and loneliness people find an unexpected solace among trees. In the desert of Beersheba, a distraught Elijah discovered hope under the shade of a broom tree. Anne Frank was sustained by a horse chestnut tree she could see from her attic window in Amsterdam. Victor Frankl tells of a dying woman at Auschwitz finding comfort in the blossoms of a tree outside her barracks. E. O. Wilson’s theory of biophilia says that human beings are genetically programmed to have an affiliation with trees and all the rest of nature. We belong to each other. In Norse creation myths, the first man and woman were formed from the dying stumps of ash and elm trees. Trees are referenced in the Bible more than any other creature in the natural world. For centuries they have been honored for their healing, medicinal properties. In India, the neem or lilac tree served as the “village pharmacy.” People used its leaves and sap for various skin and respiratory conditions. The bark of alder and willow trees has anti-inflammatory and fever-reducing qualities. The Lakota people consider the wind rustling in cottonwood leaves as soul-healing in itself. 3. Notice how trees care for each other Given your current need for “social distancing,” there’s much to be learned from trees. They regularly communicate with each other from a distance, sharing information and nutrients along underground fungal networks connecting their roots. These allow the trees to transfer water, nitrogen, and carbon as needed. Old cedar trees share nutrients with younger ones. A Douglas fir may even support a sickly paper birch nearby. In this “wood-wide web,” hub trees reach out to nurture a deeply interrelated community. Trees reach out to others in their heights as well. Thirty stories up, the canopies of redwood trees provide a habitat for a hidden world of epiphyte species—ferns, mosses, and liverworts. The generosity of trees is endless. Even in dying, they care for each other. Fallen trees become nurse logs that provide garden beds for young seedlings. Ninety percent of Sitka spruce trees on the Washington coast grow directly out of their decaying grandparents. 4. Remember that trees are survivors Old trees carry the memory of suffering borne by humans and trees alike. Think of the...

Top stories: Superblack spiders, the ‘wood wide web,’ and an antivenom funding infusion

Top stories: Superblack spiders, the ‘wood wide web,’ and an antivenom funding infusion

‘Wood wide web’—the underground network of microbes that connects trees—mapped for first time

‘Wood wide web’—the underground network of microbes that connects trees—mapped for first time

When Fungus punched Anthropos in the Gut: On Crap, Fish-eating Trees, Rhizomes and Organized Networks

Today’s internet has become like Deleuze’s societies of control, media scholars argue. The network’s invisible infrastructure, with near global reach, has amplified hierarchies, and is owned, exploited and surveilled by internet, advertising, and data-analytics companies, and by state security institutions. With the digital data produced by the often banal and quotidian activities of millions of internet users – or dividuals – a monopoly of a handful of Tech Giants accumulate massive amounts of wealth, and influence. The world wide web, various media scholars contend, has degenerated to a serpent’s coil. This article argues that the rhizomatic Wood Wide Web provides a basis from which to rethink today’s debate on the present and future of the internet, and challenges a predominant understanding of the societies control. Beneath our feet and beyond our perception, a subterranean meshwork of trees, mushrooms and fungi forms an ecology of trans-species solidarity, singularities, and creative, collaborative interactivity that could carry us outside the entrapments of the supposed totality of the societies of control. What can the World Wide Web learn from the Wood Wide Web?

Chewing up the Wood-Wide Web: Selective Grazing on Ectomycorrhizal Fungi by Collembola

The mycelia of some symbiotic ectomycorrhizal fungi form extensive networks—the so called “wood-wide web”—that have key roles in biogeochemical cycling. By interacting with myriad soil organisms such as collembola, the fungi directly affect the functioning of above- and below-ground multitrophic interactions in ecosystems. Here we tested whether the grazing activities of collembola affected the growth of ectomycorrhizal fungi in single or mixed species axenic cultures, and their impact on ectomycorrhizal diversity in litterbags in the field. We also used 14CO2 pulse-labelling to test the effects of collembola on respiratory losses of recent plant assimilate from external mycelium of ectomycorrhizal fungi in symbiosis with Scots pine or birch. We found that the effects of collembola varied across species, and caused a significant reduction in the amount of 14CO2 released from external mycorrhizal mycelium from three of the eight species combinations but increased it in one. Selective grazing also significantly affected the community structure of ectomycorrhizal fungi. Our findings demonstrate the importance of collembola in regulating ectomycorrhizal fungal diversity and activity and below-ground pathways of carbon flow.

Delayed succession from alpine grassland to savannah with upright pine: Limitation by ectomycorrhiza formation?

We investigated causes for the slow re-forestation of grassland surrounded by upright pine forest ( Pinus mugo (L.) var. uncinata) in the Swiss National Park. General opinion holds that the large numbers of grazing and trampling wild animals prevent re-forestation. However, pine trees depend on the symbioses with ectomycorrhizal fungi, especially at the study site with its poor, nutrient-limiting soil, as reflected e.g. by the low nitrogen concentration in needles. Here, we show that the ectomycorrhizal symbiosis needs to be considered as well. We investigated young trees of upright pine along four transects from the edge of the forests into the grassland and expected a gradient of mycorrhizal colonization, but all the 47 young trees collected in the four selected transects possessed well-developed ectomycorrhizas independent of their position. Similarly, ergosterol concentration in rhizosphere soil of the young trees i.e. mainly ergosterol from ectomycorrhizal fungi, showed no gradient along the transects. Morphotyping of ectomycorrhizas on the fine roots and fruit body determination revealed that Suillus granulatus was the dominant ectomycorrhizal fungal species at the study site. Young pine trees were randomly distributed along transects and did not develop preferentially at the forest edge, indicating that the common mycorrhizal network (wood wide web) established in the surrounding forest had little importance for re-colonization. Fungal fruit bodies of S. granulatus, in contrast, displayed a clustered distribution and 50% grouped within 1 m of the nearest young tree. Chamois feed on fruit bodies of S. granulatus, as observed at the site, and a model experiment showed colonization of axenic pine seedlings by S. granulatus when inoculated with faecal pellets from chamois. Chamois may profit also from the mushrooms: the concentration of nitrogen in the cap of the fruit bodies was almost 5% (pine needles 1.0%). Thus, grazing animals such as chamois may spread mycorrhizal inoculum and promote, rather than prevent, re-forestation.

The magnitude and control of carbon transfer between plants linked by a common mycorrhizal network

network does not allow ‘resource sharing’ among linked plants. It is probably irrelevant to the botanical Various claims have been made about the ecological components of a community, but it may be fundasignificance of plant-to-plant carbon movement mental for fungal members. The ‘mycocentric’ view is through common mycorrhizal networks (CMNs). Most that fungal structures within roots are parts of suggest that resource competition among intercon- extended mycelia through which fungi move carbon nected plants should be less important than previously according to their own carbon demands, not those of thought. If true, that would profoundly alter our per- their autotrophic hosts. ception of how plants interact among themselves and with their environment. However, there are difficulties Key words: Arbuscular mycorrhiza, carbon, common in quantifying the amounts of resource transferred via mycorrhizal network, ectomycorrhiza. CMNs, ensuring that transfer is genuinely through hyphae, not soil, and understanding its control. Carbon movement has not been quantified in many of the Introduction published studies. Where it has, its likely functional role has not been clarified. Some recent, well- The 7 August 1997 issue of Nature was headlined ‘The publicized research suggests that carbon transferred wood-wide web’, announcing the publication of the latest to trees via an ectomycorrhizal (EcM) network may be report (Simard et al., 1997a) of plant-to-plant carbon (C ) physiologically and ecologically important. Our view, transfer via a common mycorrhizal network (CMN ). The however, is that the evidence for this remains equi- paper itself, highlighted by Read’s (1997) commentary, vocal. Appropriate controls for the possibility of carbon left Nature readers in no doubt that this intriguing transfer via soil were not used under field conditions. phenomenon was important. Plants connected by a CMN In laboratory experiments, controls failed to clarify the could, it was claimed, share C. role of EcM links in carbon transfer. To resolve some This claim was not new. For example, Grime et al. areas of uncertainty, abundances of 13C have been (1987), suggested that grassland herbs connected by a measured to estimate carbon transfers via an arbuscu- CMN formed by arbuscular mycorrhizal (AM ) fungi lar mycorrhizal (AM) network connecting grasses and allowed C to be transferred from ‘donor’ to ‘receiver’ forbs of the same or different species. Permeable bar- species in laboratory microcosms. But Simard et al. riers to roots and hyphae allowed any direct carbon (1997a) were the first to suggest that the same was true transfer via soil to be detected. Large amounts of for ectomycorrhizal ( EcM ) networks connecting diVerent carbon (typically 10% of that in roots) were transferred tree species in the field, and that the transfer of C was between linked plants via the CMN. Transferred carbon bidirectional. This, clearly, is big news. If plants in a was never transported into shoots of ‘receiver’ plants. community can, via a CMN, really share C, this would It remained in roots, probably inside fungal structures ‘short-circuit’ one of the main constraints to the acquisiand, therefore, unavailable to the plants into which it tion of C by neighbouring plants, namely, competition. Interactions between neighbours would then be less of a was apparently transferred. Carbon transfer via an AM