introduction to the wood-wide web
By zteve t evans
Next time you go out for a walk in the woods be careful where you tread because underneath your feet connecting tree to tree, plant to plant, lies a remarkable living network that allows the exchange of information between between individual plants. This network allows the flora of the forest to send and receive information over distances from plant to plant, connecting a large and varied population of individuals together. In fact, this remarkable network is itself alive and is a web of fungi that grows on the roots of trees and plants connecting them together allowing them to communicate and to even send assistance to each other. More sinisterly, it also gives some of the plants and trees connected to the network the ability to commit types of "crime" against other members. It sounds very similar to the modern global communications system of the internet. In fact it is a living network of fungi and has been called the Earth's natural internet and many scientists refer to it as The Wood-Wide Web.
Fungal connections
We usually think of fungi as mushrooms, toadstools and mould, but these are actually the visible parts called fruits that are above ground that we see. Below ground lies a web of fine threads called mycelium. These threads run from root to root, and plant to plant, linking the roots of a multitude of different plants. Sometimes plants several meters distant are linked creating a living mesh that can conduct information and nutrients to other members of the web. It gives them the ability to help each other out, but it can also use it for darker purposes, such as sabotage, or "chemical warfare," and other types of "cyber-crime."
Mycorrhizal associations
Although some species of fungi can be harmful to some species of plants and animals life on Earth would not exist without it. About 90% of known plants have formed a mutually beneficial, or symbiotic relationship with fungi. Albert Bernard Frank, a 19th century German biologist called these relationships where the fungi lives off of the plant's roots as "mycorrhiza."
In most cases these symbiotic relationships are beneficial to both plant and fungi. Fungi receive carbohydrates and nutrients from the plants. In return the fungi helps the plant take in water, and gives nutrients such nitrogen and phosphorus through their mycelia.
In the 1960s it became recognized that mycorrhizae assisted individual plants with growth and the immune system of the host plant is enhanced. When a fungus begins to colonize a plant's roots it triggers the defense mechanism of the plant into action causing the production of chemicals intended to defend the plant. This action causes the host plant's immune system to be able to respond faster to threats and is known as "priming." It is believed that simply joining up to mycelial networks gives plants more resistance to disease and it is also known that mycorrhizae can connect plants that are quite distant from one another.
Paul Stamets in a TED talk in 2008 referred to these fungal networks as "Earth's natural internet." It was during the 1970s when he was using an electron microscope to study mycelia. He noticed similarities between mycelia and an early version of the internet used by the US Department of Defense called ARPANET.
We usually think of fungi as mushrooms, toadstools and mould, but these are actually the visible parts called fruits that are above ground that we see. Below ground lies a web of fine threads called mycelium. These threads run from root to root, and plant to plant, linking the roots of a multitude of different plants. Sometimes plants several meters distant are linked creating a living mesh that can conduct information and nutrients to other members of the web. It gives them the ability to help each other out, but it can also use it for darker purposes, such as sabotage, or "chemical warfare," and other types of "cyber-crime."
Mycorrhizal associations
Although some species of fungi can be harmful to some species of plants and animals life on Earth would not exist without it. About 90% of known plants have formed a mutually beneficial, or symbiotic relationship with fungi. Albert Bernard Frank, a 19th century German biologist called these relationships where the fungi lives off of the plant's roots as "mycorrhiza."
In most cases these symbiotic relationships are beneficial to both plant and fungi. Fungi receive carbohydrates and nutrients from the plants. In return the fungi helps the plant take in water, and gives nutrients such nitrogen and phosphorus through their mycelia.
In the 1960s it became recognized that mycorrhizae assisted individual plants with growth and the immune system of the host plant is enhanced. When a fungus begins to colonize a plant's roots it triggers the defense mechanism of the plant into action causing the production of chemicals intended to defend the plant. This action causes the host plant's immune system to be able to respond faster to threats and is known as "priming." It is believed that simply joining up to mycelial networks gives plants more resistance to disease and it is also known that mycorrhizae can connect plants that are quite distant from one another.
Paul Stamets in a TED talk in 2008 referred to these fungal networks as "Earth's natural internet." It was during the 1970s when he was using an electron microscope to study mycelia. He noticed similarities between mycelia and an early version of the internet used by the US Department of Defense called ARPANET.
Transferring carbon
Although scientists have been aware of the network for many years it has taken decades to slowly discover what its function was. In 1997. Suzanne Simard from the University of British Columbia began piecing together evidence she had found. This showed that the transfer carbon via mycelia between paper birch and Douglas fir happens. It has also been shown that phosphorus and nitrogen can be transferred by the same method.
Interacting trees
From a study in 1997, Simard thinks that young seedlings growing in shady areas are helped by large mature trees by carbon being transferred along the mycelial network. She says, "These plants are not really individuals in the sense that Darwin thought they were individuals competing for survival of the fittest" , in the documentary, Do Trees Communicate? in 2011. It is controversial area and still not fully understood. Lynne Boddy from Cardiff University in the United Kingdom, says, "We certainly know it happens, but what is less clear is the extent to which it happens."
Communication through the mycelia
Research by Ren Sen Zeng, of South China Agricultural University in Guangzhou in 2010 discovered evidence that plants can communicate with one another. The research shows that when plants are attacked by harmful fungi they use the mycelia network to send chemical signals designed to warn nearby plants of the danger.
Eavesdropping tomato plants
In one study Zeng grew pairs of tomatoes in plots allowing some to form mycorrhizae and deliberately preventing others from forming it. Once those were allowed had formed a fungal network one individual in each of the pairs were deliberately sprayed with a fungus called Alternaria solani which is a form of blight disease. The chances of the two plants sending chemical signals to each other above ground were minimized by placing plastic bags over them enclosing them completely.
Sixty five hours later Zeng tired to contaminate the other plant in the pairs with the blight but found they that the ones connected with a fungal network did not become infected so easily and even when infected suffered significantly less damage.
Zeng concluded that the tomato plants managed to 'eavesdrop' on the defense response of their neighbor via the mycorrhizae to prepare a response to the threat increasing their resistance. The mycorrhizae is not used just to share nutrients but also to monitor the health of neighboring plants so that a response can be prepared to minimize a threat of disease.
Although scientists have been aware of the network for many years it has taken decades to slowly discover what its function was. In 1997. Suzanne Simard from the University of British Columbia began piecing together evidence she had found. This showed that the transfer carbon via mycelia between paper birch and Douglas fir happens. It has also been shown that phosphorus and nitrogen can be transferred by the same method.
Interacting trees
From a study in 1997, Simard thinks that young seedlings growing in shady areas are helped by large mature trees by carbon being transferred along the mycelial network. She says, "These plants are not really individuals in the sense that Darwin thought they were individuals competing for survival of the fittest" , in the documentary, Do Trees Communicate? in 2011. It is controversial area and still not fully understood. Lynne Boddy from Cardiff University in the United Kingdom, says, "We certainly know it happens, but what is less clear is the extent to which it happens."
Communication through the mycelia
Research by Ren Sen Zeng, of South China Agricultural University in Guangzhou in 2010 discovered evidence that plants can communicate with one another. The research shows that when plants are attacked by harmful fungi they use the mycelia network to send chemical signals designed to warn nearby plants of the danger.
Eavesdropping tomato plants
In one study Zeng grew pairs of tomatoes in plots allowing some to form mycorrhizae and deliberately preventing others from forming it. Once those were allowed had formed a fungal network one individual in each of the pairs were deliberately sprayed with a fungus called Alternaria solani which is a form of blight disease. The chances of the two plants sending chemical signals to each other above ground were minimized by placing plastic bags over them enclosing them completely.
Sixty five hours later Zeng tired to contaminate the other plant in the pairs with the blight but found they that the ones connected with a fungal network did not become infected so easily and even when infected suffered significantly less damage.
Zeng concluded that the tomato plants managed to 'eavesdrop' on the defense response of their neighbor via the mycorrhizae to prepare a response to the threat increasing their resistance. The mycorrhizae is not used just to share nutrients but also to monitor the health of neighboring plants so that a response can be prepared to minimize a threat of disease.
Broad bean defenses
David Johnson and a team of the University of Aberdeen in 2013, showed that broad beans also use a fungal network to identify and ward off attacks by aphids. They discovered that when aphids attacked broad bean seedlings other seedlings connected to them via the fungal network activated chemical defences to protect against the aphid attack. Those broad bean seedlings that were not connected did not respond. Johnson said, "Some form of signalling was going on between these plants about herbivory by aphids, and those signals were being transported through mycorrhizal mycelial networks."
The dark side
Plants connected to the fungal network gain many advantages but there are also disadvantages. The mycelial network has been compared to the internet although it is local and not global. It can allow disease to spread, and help malevolent organisms neighbors take advantage of others.
For example some plants are parasitic and can only survive by living off of other plants. Some plants do not have chlorophyll so they cannot make their own energy. One such plant is the phantom orchid which cannot use photosynthesis to produce energy and needs to obtain its supply of carbon from the mycelia from neighboring trees that they both are connected to.
On the positive side it can be used for communication and to monitor neighboring plants and as an early warning system of attack. Other species of orchid are "mixotrophs" and can use photosynthesis but they also can obtain carbon from neighboring plants they are linked to through the fungal network.
Allelopathy - sabotage!
In the natural world important resources such as water, nutrients, space and light sometimes have to be competed for. To gain an advantage, some plants can release chemicals via the fungal network to deter or harm competitors. This is known as "allelopathy" and many species of trees are known to use these tactics to secure vital resources for themselves. There are some some species of Eucalyptus and American sycamores as well as sugarberries and acacias that deter other plants from establishing themselves or inhibit microbes from around a neighbor's root system. Not all scientists agree that this happens with some thinking that the soil would absorb chemicals before it reached its intended victim or be broken down by microbial action in the soil.
Kathryn Morris, a chemical ecologist in 2011, conducted an experiment where golden marigolds were grown inside cylinders which were enclosed in mesh and placed in pots. The mesh had holes small enough to prevent roots growing through but big enough to allow mycorrhizal fungi to grow through. Morris prevented mycorrhizal fungi from growing through half of the cylinders by turning them regularly preventing them forming and connecting to the fungal network the other half of the plants were connecting to.
Dr Morris looked in the soil for two compounds that marigolds release that deter the growth of neighboring plants and help eliminate nematode worms that can damage plant tissue, stems, flowers and foliage. In the cylinders where the fungi was allowed to develop and form a network one compound was 179% higher, and the other 278% higher, than in the cylinders where fungi was prevented from developing a network. Morris believes this implies that the mycelia was used to move two compounds to the required place.
David Johnson and a team of the University of Aberdeen in 2013, showed that broad beans also use a fungal network to identify and ward off attacks by aphids. They discovered that when aphids attacked broad bean seedlings other seedlings connected to them via the fungal network activated chemical defences to protect against the aphid attack. Those broad bean seedlings that were not connected did not respond. Johnson said, "Some form of signalling was going on between these plants about herbivory by aphids, and those signals were being transported through mycorrhizal mycelial networks."
The dark side
Plants connected to the fungal network gain many advantages but there are also disadvantages. The mycelial network has been compared to the internet although it is local and not global. It can allow disease to spread, and help malevolent organisms neighbors take advantage of others.
For example some plants are parasitic and can only survive by living off of other plants. Some plants do not have chlorophyll so they cannot make their own energy. One such plant is the phantom orchid which cannot use photosynthesis to produce energy and needs to obtain its supply of carbon from the mycelia from neighboring trees that they both are connected to.
On the positive side it can be used for communication and to monitor neighboring plants and as an early warning system of attack. Other species of orchid are "mixotrophs" and can use photosynthesis but they also can obtain carbon from neighboring plants they are linked to through the fungal network.
Allelopathy - sabotage!
In the natural world important resources such as water, nutrients, space and light sometimes have to be competed for. To gain an advantage, some plants can release chemicals via the fungal network to deter or harm competitors. This is known as "allelopathy" and many species of trees are known to use these tactics to secure vital resources for themselves. There are some some species of Eucalyptus and American sycamores as well as sugarberries and acacias that deter other plants from establishing themselves or inhibit microbes from around a neighbor's root system. Not all scientists agree that this happens with some thinking that the soil would absorb chemicals before it reached its intended victim or be broken down by microbial action in the soil.
Kathryn Morris, a chemical ecologist in 2011, conducted an experiment where golden marigolds were grown inside cylinders which were enclosed in mesh and placed in pots. The mesh had holes small enough to prevent roots growing through but big enough to allow mycorrhizal fungi to grow through. Morris prevented mycorrhizal fungi from growing through half of the cylinders by turning them regularly preventing them forming and connecting to the fungal network the other half of the plants were connecting to.
Dr Morris looked in the soil for two compounds that marigolds release that deter the growth of neighboring plants and help eliminate nematode worms that can damage plant tissue, stems, flowers and foliage. In the cylinders where the fungi was allowed to develop and form a network one compound was 179% higher, and the other 278% higher, than in the cylinders where fungi was prevented from developing a network. Morris believes this implies that the mycelia was used to move two compounds to the required place.
Lettuce experiment
Dr Morris then used the soil from both sets of containers to grow lettuce seedlings. She found that after 25 days the lettuce seedlings growing in the cylinders with the toxins in were 40% less in weight than those growing in the cylinders that had been kept free from mycelia. According to Dr Morris, "These experiments show the fungal networks can transport these chemicals in high enough concentrations to affect plant growth.”
However, other scientists have suggested that the chemicals may not work so well outside of a laboratory environment. To investigate this further Michaela Achatz and colleagues from the Berlin Free University looked to see what happens the wild.
Juglone
The black walnut tree is a well known and well studied example of allelopathy and is known to adversely affect the growth of many plants that may grow near to it. It releases the chemical juglone from roots and leave. Juglone inhibits the growth of many plants including cucumbers, potatoes and other staple crops.
The researchers positioned pots around walnut trees. Some of the pots were allowed to be penetrated by the fungal network. Others were rotated to prevent fungi penetration. The soil in these pots with fungi was found to contain 4 times more juglone than pots that had been rotated to prevent the growth of a fungi reaching the roots. They discovered that the roots of tomato seedling planted in pots with juglone in the soil on average weighed 36% less than those without.
Crafty plants
It is also thought possible that some species of plant such as soft brome, slender wild oat, and spotted knapweed, are able to alter the structure of the fungal network and change the fungal make-up of soils to suit their needs.
Animals and the fungal network
Worms and insects may also make use of the fungal network. Compounds produced by some plants may attract beneficial fungi and bacteria to their roots but the signals they give out can attract worms and insects looking for food. Morris thought it may be possible that signals were sent out as compounds were transported around the fungal network. This movement of chemicals may bring the plants to the attention of animals, though she points out this has yet to be proven.
The “Wood-Wide Web”
The growing amount of evidence concerning the fungal network has led many many biologist to use the term "wood wide web" when describing or referring to this extraordinary natural network. Morris says, "These fungal networks make communication between plants, including those of different species, faster, and more effective," and adds, "We don't think about it because we can usually only see what is above ground. But most of the plants you can see are connected below ground, not directly through their roots but via their mycelial connections."
The fungal network is an example of how separate organisms are connected and may share a dependence on one another. Boddy says, "Ecologists have known for some time that organisms are more interconnected and interdependent," and the fungal network provides the connections in many ways.
© 12/02/2015 zteve t evans
Dr Morris then used the soil from both sets of containers to grow lettuce seedlings. She found that after 25 days the lettuce seedlings growing in the cylinders with the toxins in were 40% less in weight than those growing in the cylinders that had been kept free from mycelia. According to Dr Morris, "These experiments show the fungal networks can transport these chemicals in high enough concentrations to affect plant growth.”
However, other scientists have suggested that the chemicals may not work so well outside of a laboratory environment. To investigate this further Michaela Achatz and colleagues from the Berlin Free University looked to see what happens the wild.
Juglone
The black walnut tree is a well known and well studied example of allelopathy and is known to adversely affect the growth of many plants that may grow near to it. It releases the chemical juglone from roots and leave. Juglone inhibits the growth of many plants including cucumbers, potatoes and other staple crops.
The researchers positioned pots around walnut trees. Some of the pots were allowed to be penetrated by the fungal network. Others were rotated to prevent fungi penetration. The soil in these pots with fungi was found to contain 4 times more juglone than pots that had been rotated to prevent the growth of a fungi reaching the roots. They discovered that the roots of tomato seedling planted in pots with juglone in the soil on average weighed 36% less than those without.
Crafty plants
It is also thought possible that some species of plant such as soft brome, slender wild oat, and spotted knapweed, are able to alter the structure of the fungal network and change the fungal make-up of soils to suit their needs.
Animals and the fungal network
Worms and insects may also make use of the fungal network. Compounds produced by some plants may attract beneficial fungi and bacteria to their roots but the signals they give out can attract worms and insects looking for food. Morris thought it may be possible that signals were sent out as compounds were transported around the fungal network. This movement of chemicals may bring the plants to the attention of animals, though she points out this has yet to be proven.
The “Wood-Wide Web”
The growing amount of evidence concerning the fungal network has led many many biologist to use the term "wood wide web" when describing or referring to this extraordinary natural network. Morris says, "These fungal networks make communication between plants, including those of different species, faster, and more effective," and adds, "We don't think about it because we can usually only see what is above ground. But most of the plants you can see are connected below ground, not directly through their roots but via their mycelial connections."
The fungal network is an example of how separate organisms are connected and may share a dependence on one another. Boddy says, "Ecologists have known for some time that organisms are more interconnected and interdependent," and the fungal network provides the connections in many ways.
© 12/02/2015 zteve t evans
References and Attributions
Copyright February 12th, 2015 zteve t evans
Copyright February 12th, 2015 zteve t evans