Glowing plants
Representative picture of plants. Seon-Yeong Kwak/MIT

Plants are intelligent enough to not just connect trees to the earth but also with each other due to mycorrhizae -- the symbiotic unions of fungi and root long known to help plants absorb nutrients from the soil, a study has revealed.

Suzanne Simard, a professor in the Department of Forest and Conservation at the University of British Columbia, who studied how carbon flowed between paper birch and Douglas fir trees, found that mycorrhizae-linked trees formed networks and exchanged nutrients and water in a literally pulsing web that included not only trees but all of a forest's life.

Simard along with other scientists studied roots, chemical signals and even the sounds plant made – pushing the study into the realm of intelligence – to find that Mother Trees at the centre of communities were linked to one another and communicated with other trees.

According to her, the research rather than biological automata focused on the understanding of capacities that in animals are regarded as learning, memory, decision-making, and even agency. "The work I and others have been doing -- looking at kinship in plants, how they recognize each other and communicate -- involves the roots. It's not just those cells at a plant root's tip, but their interaction with fungus, that determines a root's behaviour," she said.

The researcher while studying the behaviour between a mother tree, a kin seedling, and a stranger seedling found that the mother tree chose which one to provide for, and provided for her own kin over something that was not her kin. "We know old trees change their behaviour to give advantages to their own kin. A parent tree will kill off its own offspring if they're not in a good place to grow."

She explained root systems and the mycorrhizal networks behaved like neural networks – just like the seeding of intelligence in our brains – through links and nodes and had all the structures and functions relating to intelligence as well as communication.

"You can smell the defence chemistry of a forest under attack. Something is being emitted that has a chemistry that all those other plants and animals perceive, and they change their behaviours accordingly," she added.

The new findings, however, contradict an earlier study published in the journal Trends in Plant Science that suggested plants did not have consciousness. The scientists who took part in the earlier study concluded this after analyzing the research of neuroscientist Todd Feinberg and evolutionary biologist Jon Mallatt which tried to explore the evolution of gaining consciousness by studying simple and complex animal brain systems.

Lincoln Taiz, Professor Emeritus of molecular, cell, and developmental biology at the University of California at Santa Cruz revealed that the absence of neurons in plants was a clear indication that they did not have consciousness. The report, however, suggested that plants appeared to be intelligent when it came to their genetically programmed behaviors.

Scientists have also been measuring acoustics in trees and realizing there are lots of sounds that we cannot hear, which could be part of their communication, according to Nautilus.