When I was teaching environmental education in CT, we used to tell our students about the mysterious “Internet of the Forest.” The “Internet of the Forest” is the network of fungal hyphae connecting tree roots, allowing trees in different parts of the woods “to talk” to one another. (I’m not sure if the kids believed me, especially since we made a big deal of taking away their electronic devices while they visited us.)
But it’s a thing! Really! And it’s very gratifying that the internet and popular press has caught up with it.
Recently, there have been a slew of articles and podcasts about forest mycorrhizal networks (aka “The Wood Wide Web”) that made me think back to the Mesquite Arbuscular mycorrhizae project.
As an undergraduate, I had the opportunity to work on a research project involving mycorrhizae, the mutualistic relationship between fungi and plant roots. The plants and fungal hyphae (rootlets) cooperate by sharing water, carbon and nitrogen, improving the growth and survival of both organisms. I remember my Professor enthusiastically cheering, “Mycorrhizae is Latin for *really cool!*” When I told people about the project, and their eyes would start to glaze over at the technical terms I was spouting to describe the work, I fell back on this slogan. A lot.
We were studying the frequency of mycorrhizal fungal spores and other bits that could colonize plants (aka Mycorrhizal inoculation potential) occurring in the soil around the roots of Mesquite trees in the Sonoran desert of Arizona. We dug a hole in the desert soil alongside the root ball of a mesquite tree, and took soil samples from different depths. Since it’s really hard to count microscopic spores and hyphae bits in the soil samples, we used corn plants as a proxy. We grew corn plants in the various soil samples, and then harvested the corn roots to examine them for colonization by mycorrhizal hyphae.
After dyeing the roots with a blue dye that sticks to fungal cells, but not plant cells, we spent many hours poring over the roots samples with a dissecting microscope. Against a grid, we counted intersections of the blue hyphae with the clear corn roots, which could give us an idea of the inoculation potential of the soil in which the corn plant grew. By the end of the project, which I came to think of as “Tangled up in Blue“, I had extremely chapped hands from work in the unheated lab and particular pride in knowledge of an obscure ecological phenomenon that no one else seemed to be excited about.
But now mycorrhizal networks have arrived! Maybe it’s their similarity to the internet networks that have become such an enmeshed part of our lives. Or maybe its a growing recognition that non-human entities and systems have their own ways of communicating. To me, it’s a super-exciting development when a variety of media outlets report on the inherent awesomeness of these tangled webs.
- RadioLab has a great podcast From Tree to Shining Tree, that is an introduction to how networks of tree roots and fungi can communicate across the forest.
- Suzanne Simard’s TED Talk goes into some more detail about how she conducted her experiments in the British Columbia forests.
- Ed Yong in the Atlantic and Robert MacFarlane in the New Yorker both describe some of the work different scientists are doing with the “Wood Wide Web.”