by Yogi Hendlin and Michael Marder
JULY 21, 2014
To human knowledge, it seems that the better our technology, the more intelligent and communicative plants become. But, surely, there hasn’t been a sudden surge in plant intelligence in the last thirty years; it was our perception of plants that has been growing and, to some extent, we ourselves have grown. This leads to the question: If in the last decades we’ve discovered myriad new ways plants communicate, both internally and externally, then what other mysteries remain opaque to our knowledge? And, more importantly, how can what we already know about plant communication lead us to reconsider the general notion of communication?
Let us first try to clear our heads and hear what the word itself has to say. Before signifying the transfer of information, the sending of messages, or the stimulus-response model, communication means the process of creating a community, teasing out something in common, shared by all. At least since Greek antiquity, the vegetal principle of vitality has stood for the most basic type of life, shared by plants, animals, and humans. The capacities to acquire nourishment and to reproduce, grouped under this principle, are common to all kinds of living beings. Yet, these are the same capacities that modern science, Darwinism included, has loaded with egoistic intentionality, if not at the level of individual specimens, then at the level of the species. Instead of assembling a biological community, the principle of vitality has been often harnessed for the purpose of setting living beings apart, isolated by their exclusive interests and concerns with survival.
To recover this lost sense of communication, we ought to return to the ontology of plants, including the way they distribute resources that are required for nourishment. The method of “mother trees,” for example, directing the flow of nutrients between generations in groves (even to different tree species) (Simard et al., 1997), demonstrates a remarkable amount of care and sharing between organisms. While the mother trees funnel more nutrients to their own progeny than to other trees, there is an economy of nutrients and energy circulation (thanks to the mycorrhizal helper-fungi that facilitate the functioning of root systems) that lies somewhere beyond altruism and selfishness. Indeed, it is more of a communist model of “from each according to their ability, to each according to their needs” than a system of abstracting self-interest from the interests of one’s neighbors. Plant scientists even postulate that a plant’s leaves produce extra energy so they can share this energy with other plants in the undergrowth that receive less light (Selosse et al., 2006).
If plants communicate with one another, it is because they are communal through and through. They are not individuated, as most animals are, with clear boundaries between self and other. Plants simply cannot be conceived as individual organisms, but instead as subjects with deeply pluralistic identities, from their own decentralized intelligence—their “brain analogue” existing in their manifold roots—to their interdependent survival. On the face of it, plants’ radical otherness has to do, in part, with this fluidity of the distinction between self and other. But are humans really excluded from the communal ontology of plants and, by extension, from their mode of communication?
Human relations also in the past century perhaps have been misunderstood as the action of individualistic purely selfish rational actors. In economics, much of our communication, especially in the marketplace, has been reduced to shrewd cost-benefit calculations. But as David Graeber has argued in his 2011 book Debt: The first 5,000 years, such exchange-based interactions are only guided by selfish rational-actor principles with people one never expects to see again, that is to say, in the most uprooted social context imaginable. Conversely, sharing with friends and community members in many societies is a simple act of giving, knowing that one can call on a favor if need be, but without reducing favors to the quantitative accounting of quid pro quo. We share in order to get on, and get by. Plants and many humans, too, operate in their daily interactions more according to a gift economy model than based on calculating the returns on their investments (though gifting also opens up a whole world of complications, as Graeber and Derrida have pointed out).
Besides creating a community with other plants of the same species that might not be perceived as distinct from the communicating “self,” vegetal communication forges communities across species and biological kingdoms. Plants marshal beneficial insectivorous insects, attracting them by spraying specifically targeted volatile organic chemical scents in order to ensure pest control against herbivorous predators (Allmann and Baldwin 2010).As we have already mentioned, they cooperate with fungi near the root apex area in order to optimize their intake of nutrients.And these are just two of many examples, in which plants construct biological networks that are symbiotic rather than competitive, based on shared interests rather than mutually exclusive gains.
To sum up: before considering the content or the form of communication, whether human or nonhuman, it is crucial to ask the patent philosophical question, “What is communication?” Plants help us provide some of the initial responses to this question by revealing that the “message,” or what is communicated, is not separate from the communicating organism, which is a communal being at every level of its cellular, tissue, and environmental architecture. Much in the same way, human language, erroneously identified with communication in toto, is not a tool for the transfer of information but part and parcel of our ontology, our inherent communal makeup. This is, no doubt, the sense of Martin Heidegger’s often misinterpreted statement that “language is the house of being,” which ought to be taken outside its narrow human confines and adapted to non-human modes of communication. And plant language as the house of plant being is an excellent starting point in this difficult endeavor.
Allmann, Silke, and Ian T. Baldwin. 2010. “Insects Betray Themselves in Nature to Predators by Rapid Isomerization of Green Leaf Volatiles.” Science, 329: 1075-8.
Selosse, Marc-André, Franck Richard, Xinhua He and Suzanne W. Simard. 2006. “Mycorrhizal networks: des liaisons dangereuses?” Trends in Ecology and Evolution. 21(11): 621–628.
Simard, Suzanne W., David A. Perry, Melanie D. Jones, David D. Myrold, Daniel M. Durall & Randy Molina. 1997. “Net transfer of carbon between ectomycorrhizal tree species in the field.” Nature, 388: 579-582.