Blog Post 9: Do Plants Talk to Each Other?
Do plants talk to each other? Lots of living things have complex social networks. Even though we cannot always understand what they are saying, it seems obvious that when two squirrels are chattering at each other, or when a bird is singing in the backyard, that they are sending some sort of message. So, what about plants? I don’t walk into a forest and hear the trees chatting about the weather, or debating the day’s news. They don’t really make any noise or intentional movements, other than the swaying of branches or rustling of leaves. So, does this mean that they have nothing to say?
The answer is that plants have plenty to say! We just need to know how to listen. One of the coolest things I know about nature is that plants are constantly communicating, even if we cannot hear them. Plant ecosystems have complex social networks, just like us. However, instead of communicating with words, plants communicate through fungi.
These secret messengers of the plant world are called mycorrhizal fungi. They grow on the roots of plants, and connect entire ecosystems, like a forest version of Instagram or Facebook. This system is well very well established, as these fungi have been around for about 400 million years (Van Der Heijden & Horton, 2009). For a small price of a donation of carbon from host plants, this fungal network carries messages from plant to plant across an ecosystem.
These messages serve many purposes, and one of the most amazing is as a warning system. Plants use this fungal network to warn other plants about insect attacks and parasites. For example, bean plants produce certain chemicals when attacked by aphids. However, when a plant begins to be eaten, it will also send a signal to neighboring plants. Even if these plants have not been attacked yet, they will start producing this anti-aphid chemicals (Babikova et al., 2013). Through this warning system, plants help warn their neighbors of danger, so they can defend themselves.
Another cool use of this communication system is parenting. While it may seem that plants are absentee parents, they are more involved than they appear. Through mycorrhizal networks, mature trees can send resources to their saplings. This helps more seedlings to survive, and small trees have less of a mortality rate when connected to this kind of network (Teste et al., 2009).
So essentially, mycorrhizal fungi are the interpreters of the plant world. They spread messages about issues of concern, such as insect attacks or a lack of resources, around a community. Interpreters can do the same thing. There are many complex issues affecting the natural world right now, including climate change and pollution. Interpreters can relate information about a park, museum, or historical monument to these larger issues, and use their platforms to educate the public (Knudson et al., 2018). Just like the fungi in the forest, they can pass along information to effectively reach a wider audience. I think it is truly amazing that we can learn lessons about communication from plant systems.
Babikova, Z., Gilbert, L., Bruce, T. J. A., Birkett, M., Caulfield, J. C., Woodcock, C., Pickett, J. A., & Johnson, D. (2013). Underground signals carried through common mycelial networks warn neighbouring plants of aphid attack. Ecology Letters, 16(7). https://doi.org/10.1111/ele.12115
Knudson, D. M., Beck, L., Cable, T. T. (2018). Interpreting Cultural and Natural Heritage: For a Better World. Sagamore Publishing LLC. https://sagamore.vitalsource.com/books/9781571678669
Teste, F. P., Simard, S. W., Durall, D. M., Guy, R. D., Jones, M. D., & Schoonmaker, A. L. (2009). Access to mycorrhizal networks and roots of trees: Importance for seedling survival and resource transfer. Ecology, 90(10). https://doi.org/10.1890/08-1884.1
Van Der Heijden, M. G. A., & Horton, T. R. (2009). Socialism in soil? the importance of mycorrhizal fungal networks for facilitation in natural ecosystems. Journal of Ecology, 97(6). https://doi.org/10.1111/j.1365-2745.2009.01570.x