It seems we’re not the only living things on earth to use a high-speed information superhighway. As detailed in a recent BBC science post online, mushrooms also have their own version. The bodies of most fungi are made up of tiny threads known as mycelium, linking roots to different plants. Thanks to this invisible interweb, a tree in your backyard is probably linked to shrubs several feet away via mycelia. But this version of the web isn’t for sharing funny cat videos or vacation photos. Through this linked fungal network, friendly plants can transfer nutrients and information to their neighbors—or destroy unwanted flora by spreading toxic chemicals through the network.
Approximately 90 percent of plants fall into the mutually beneficial cohabitation category—dubbed by 19th-century German biologist Albert Bernhard Frank as “mycorrhiza” partnerships. Through mycorrhizal associations plants give fungi precious carbohydrates for food. In exchange, the fungi collect water and provide nutrients like phosphorus and nitrogen that help plants grow.
In his 2008 TED talk, fungus expert Paul Stamets coined the phrase “Earth’s natural internet” to describe the mycorrhizal communications. In the 1970’s Stamets began using an electron microscope to study fungus and soon started noticing similarities between mycelia and ARPANET, the US Department of Defense’s early internet protocol. But it took decades to fully unlock the mysteries of the fungal internet.
Another pioneer in the area, Suzanne Simard of University of British Columbia in Vancouver, discovered that Douglas fir and paper birch trees share carbon via mycelia. And just as Shel Silverstein once asserted, plants really are giving entities. Simard, through her findings, now believes that large trees are able to share resources with smaller, younger saplings, utilizing the fungal internet. Without this help, many seedlings wouldn’t be able to survive. All of this is discussed in Simart’s 2011 documentary Do Trees Communicate?
This fungal system also acts as a neighborhood watch. In 2010 Ren Sen Zeng of South China Agricultural University discovered that when plants are invaded by harmful fungi, they transmit chemical signals, warning nearby plants to be on guard. As Zeng and his colleagues noted, “We suggest that tomato plants can ‘eavesdrop’ on defense responses and increase their disease resistance against potential pathogen.” This behavior is also seen in broad beans, who use these networks to warn against aphid attacks.
But not all plants are team players. Plants that don’t produce their own chlorophyll, like the phantom orchid, are left with no choice but to “steal” carbon through these channels. But this theft is a little more serious than tapping into a neighbor’s WIFI. As part of the ongoing “plant battle,” some are forced to release toxic chemicals to protect resources and harm rivals. This plant cyber warfare is called “allelopathy” and is most commonly seen in eucalyptus, American sycamores, and the acai palm.
So next time you’re having a picnic in the park just think—you’re actually witnessing a highly evolved net war taking place right before your eyes.
