Empirical Research

What Are Plants Capable Of?

The current generation of plant ethics draws extensively on empirical resources. This is hardly surprising, seeing as recent developments in botany provide exciting new insights into the capabilites of plants that facilitate radically novel philosophical takes on plant life. Under the label "plant neurobiology", a series of cutting-edge research questions are being discussed, viz. whether or not plants can think, learn, remember, and communicate. Signs of adaptive behaviour and the ability to send and respond to signals suggest that they might, but the adequate interpretation of the data is still open to debate.

For an introductory paper on plant neurobiology that also includes an historical overview, see:

  • Brenner, Eric D., Rainer Stahlberg, Stefano Mancuso, Jorge Vivanco, František Baluška, and Elizabeth Van Volkenburgh. 2006. "Plant Neurobiology: An Integrated View of Plant Signaling." Trends in Plant Science 11 (8): 413–419.

This anthology contains articles by a vast number of distinguished experts in the field:

  • Baluška, František, Stefano Mancuso, and Dieter Volkmann, eds. 2006. Communication in Plants. Neuronal Aspects of Plant Life. Berlin/Heidelberg: Springer.

Two of the most important cases for the claim that plants display a form of intelligence that have been made in book format are Plant Behaviour and Intelligence by Anthony Trewavas and Brilliant Green by Stefano Mancuso and Alessandra Viola:

  • Trewavas, Anthony. 2014. Plant Behaviour and Intelligence. Oxford: Oxford University Press.
  • Mancuso, Stefano and Alessandra Viola. 2015. Brilliant Green. The Surprising History and Science of Plant Intelligence. Translated by Joan Benham. Washington/Covelo/London: Island Press.

For a nuanced discussion of the issue, we recommend the debate between Trewavas and Richard Firn:

  • Trewavas, Anthony. 2003. "Aspects of Plant Intelligence." Annals of Botany 92 (1): 1–20.
  • Firn, Richard. 2004. "Plant Intelligence: An Alternative Point of View." Annals of Botany 93 (4): 345-351.
  • Trewavas, Anthony. 2004. "Aspects of Plant Intelligence: An Answer to Firn." Annals of Botany 93 (4): 353-357.

Ramsey Affifi discusses plant intelligence with a focus on learning and memory:

  • Affifi, Ramsey. 2013. "Learning Plants: Semiosis Between the Parts and the Whole." Biosemiotics 6 (3): 547–559.

Here are two further critical views on plant intelligence:

  • Alpi, Amedeo, Nikolaus Amrhein, Adam Bertl, Michael R. Blatt, Eduardo Blumwald, Felice Cervone, Jack Dainty, et al. 2007. "Plant Neurobiology: No Brain, No Gain?" Trends in Plant Science 12 (4): 135–136.
  • Cvrčková, Fatima, Helena Lipavská, and Viktor Žárskỳ. 2009. "Plant Intelligence: Why, Why Not or Where?" Plant Signaling & Behavior 4 (5): 394–399.

Apart from plant intelligence in general, there is also a growing body of literature on plant communication in particular. Botanical evidence suggests that plants communicate (with themselves, with each other, and even with other kinds of organisms such as bacteria or fungi) through a number of different channels. This raises questions like whether plant signalling really is a kind of communication properly so called, and if so, whether it provides sufficient grounds to attribute intelligence to plants.

For plant communication via airborne signals, see:

  • Heil, Martin, and Richard Karban. 2010. "Explaining Evolution of Plant Communication by Airborne Signals." Trends in Ecology & Evolution 25 (3): 137–144.
  • Reddy, Gadi V.P. 2012. "Recent Trends in the Olfactory Responses of Insect Natural Enemies to Plant Volatiles." In Biocommunication of Plants, edited by Günther Witzany and František Baluška, 281-301. Berlin/Heidelberg: Springer.

For plant communication via electrical signals, see:

  • Fromm, Jörg. 2006. "Long-Distance Electrical Signaling and Physiological Functions in Higher Plants." In Plant Electrophysiology. Theory and Methods, edited by Alexander G. Volkov, 269-285. Berlin/Heidelberg: Springer.
  • Davies, Eric. 2006. "Electrical Signals in Plants: Facts and Hypotheses." In Plant Electrophysiology. Theory and Methods, edited by Alexander G. Volkov, 407-422. Berlin/Heidelberg: Springer.

For plant communication via chemical signals, see:

  • Balmer, Dirk and Brigitte Mauch-Mani. 2012. "Plant Hormones and Metabolites as Universal Vocabulary in Plant Defense Signaling." In Biocommunication of Plants, edited by Günther Witzany and František Baluška, 37-50. Berlin/Heidelberg: Springer.
  • Dinant, Sylvie and Paula Suárez-López. 2012. "Multitude of Long-Distance Signal Molecules Acting Via Phloem." In Biocommunication of Plants, edited by Günther Witzany and František Baluška, 89-121. Berlin/Heidelberg: Springer.

For plant communication via root networks, see:

  • Johnson, David, and Lucy Gilbert. 2015. "Interplant Signalling through Hyphal Networks." New Phytologist 205 (4): 1448–1453.
  • Selosse, Marc-André, Franck Richard, Xinhua He, and Suzanne W. Simard. 2006. "Mycorrhizal Networks: Des Liaisons Dangereuses?" Trends in Ecology & Evolution 21 (11): 621–628.