Trees communicating? Protecting their offspring? Sending warning signals? Even helping “competing” species? These are some of the incredible things we have heard about the “Wood Wide Web”. But, is it true? Or has the story got ahead of the science? A team of mycorrhizal researchers has discovered some painful truths about these fungal connections we have all come to be fascinated with. Justine Karst breaks down the myths and misconceptions about Common Mycorrhizal Networks (CMN), and the pain it caused her to do so. The first 50min is the science, the last 50min is the story behind it.

Resources

Justine’s Lab

Justine’s paper

Sponsors

West Fraser

GreenLink Forestry Inc.

Quotes

58.47 - 59.00: “If it makes you really mad, or if it makes you really happy, pause.”

Takeaways

The wood wide web (09.17)

Justine talks about how the belowground transfer of carbon in the field is not conclusively proven to occur through a mycorrhizal network, what some call the ‘wood wide web’. A common mycorrhizal network is formed when roots of two different plants are physically connected by fungal tissue.

Exploring functions (15.22)

Only two studies in the world have done high-resolution sampling showing with high certainty that the same fungus links two roots of different trees. Mycorrhizal fungi are essential in forests, but the function of common mycorrhizal networks is inconclusive.

Debunking myths (27.23)

The paper that Justine, Melanie and Jason worked on evaluated some of the widely held assumptions about common mycorrhizal networks - that they are widespread in forests, their benefits to trees, and the communication of warning signals between trees through the networks. Not enough studies have been done to conclusively support these ideas, and the methods used are difficult to control for confounding effects.

The truth (43.40)

Justine, Melanie and Jason could not find any peer-reviewed, published field studies testing the claim that trees recognize their kin and send warning signals to them. One graduate thesis even proved those claims wrong. When they looked at how scientists interpret these claims, they found that nearly 50% of the papers today citing original studies made unsupported statements. 

“We’re looking to nature for how society should behave or act” (55.50)

While Justine wants to see people rethink their connections with nature, she does not want science to be distorted towards that end. Because of the misinformation about common mycorrhizal networks, the difference between possibility and established fact has blurred.

“I’d rather know the truth than believe in a fairytale” (1.06.00)

Justine acknowledges that her study may have burst the bubble for many but believes that the truth is helpful to all scientists. However, the lack of conclusive evidence on mycorrhizal common networks, in her opinion, does not devalue the conversations around species interactions.

Critically engaging with feedback (1.13.12)

Justine, Melanie and Jason’s study had three scientists sign the review, and their associating their reputation with the study was reassuring to her. The trio revised the manuscript based on their feedback and ensured it was thorough.