The vegetable kingdom is not one that we typically think of as intelligent and highly social, in contrast to mammals like whales or elephants. However, scientists are demonstrating through studies of plant neurobiology that many plants are autonomous, able to differentiate between self and non-self, capable of complex and adaptive behaviors, able to communicate and warn other plants of danger, and able to enlist allies to aid them. Many forms of plant life, including trees and forests, are entitled to be treated with dignity because they are sensing, highly social organisms that communicate extensively, interact with their surroundings, learn from experience, are able to integrate diverse sources of information and act accordingly, and can distinguish between self and not-self and between kin and non-kin.[1]
Research shows that plants appear to be able to make complex decisions, being able to distinguish between inner and outer conditions and anticipate future risks.[2] They are able to adapt to temperature and environmental change without requiring a lengthy evolutionary change.[3] Relying on odors emitted by threatening species, plants can prime defenses ahead of time[4] and cry for help.[5]
We are only recently appreciating the complex social development of plants and have not yet had public discussions about the implications of practices we impose on this kingdom (e.g., forest clearcutting, genetic modification) in the context of viewing plants as “nonhuman persons.” Indeed, we have strategies to exploit the intelligence of plants—for example, harnessing their ability to seek out their fair share of sunlight in order to ensure high-yield crops.[6]
Switzerland has again been a leader in creating a Bill of Rights for Plants, which states that “living organisms should be considered morally for their own sake because they are alive.”[7]
[1] Swiss Federal Ethics Committee for Non-Human Biotechnology, The Dignity of Living Beings with Regard to Plants: Moral Consideration of Plants for Their Own Sake (April 2008); C.K. Yoon, “Loyal to Its Roots,” The New York Times (10 June 2008); Research at the International Laboratory of Plant Neurobiology (LINV) in Italy; N. Martinelli, “Smarty Plants: Inside the World’s Only Plant-Intelligence Lab,” The New Yorker (30 October 2007); F. Koechlin, “The Dignity of Plants,” Plant Signaling & Behavior 4, no. 1 (2009): 78-79; J. Christmas, “Plants Recognize Their Siblings, Biologists Discover,” Daily News.
[2] Helmholtz Centre For Environmental Research-UFZ, “Complex Plant Behavior? In Fight Against Parasites, Barberry Sacrifices Seeds Depending on Survival Chance,” ScienceDaily (4 March 2014).
[3] Plataforma SINC, “Plasticity of Plants Helps Them Adapt to Climate Change,” ScienceDaily (17 March 2011).
[4] Penn State, “Plant Sniffs Out Danger to Prepare Defenses Against Pesky Insect,” ScienceDaily (17 December 2012).
[5] Wageningen University and Research Centre, “Plants Cry for Help When an Attack Can Be Expected,” ScienceDaily (6 September 2012).
[6] Salk Institute, “How Plants Grow to Escape Shade: Findings Could Lead to High-Yield Crops,” ScienceDaily (16 April 2012).
[7] Swiss Federal Ethics Committee for Non-Human Biotechnology, The Dignity of Living Beings with Regard to Plants, op.cit.