The book “Light Eaters” and 5 questions about the incredible abilities of plants

Are plants conscious?

At the beginning of her journey, Zoë Schlanger was convinced that she knew exactly what a plant was. However, conversations with botanists forced her to completely redefine how she perceives the green world. The journalist focused on a relatively young field of science – the study of plant behavior. She discovered evidence that they are much more sophisticated than we thought.

For example, you will learn the results of scientific research showing that plants can distinguish themselves from others and assess whether they are related to them. Their defense mechanisms are also astonishing: semilunar beans and tobacco, in response to the attack of feeding insects, can “call” their natural enemies. In turn, a certain variety of tomato secretes chemicals that cause hungry caterpillars to eat each other instead of devouring the leaves. As the author admits:

Only now have I realized that there is more going on in the life of every plant I pass – both above and below ground – than I ever imagined.

How can a scent send a message?

The language of smells allows messages to be sent directly through the air. Biologist Richard Karban’s observations showed that even tobacco can interpret the chemicals secreted by sage. The same scientist found that sage responds much more strongly to warnings sent by its genetic relatives – for example, that hungry herbivores are feasting nearby.

And ecologists Aino Kalske, Kaori Shiojiri and André Kessler noticed a fascinating difference in the behavior of goldenrod. Plants living in quiet areas, rarely disturbed by pests, when attacked, emit alarm signals that are understandable only to their immediate family. However, the same plants growing in more dangerous areas communicate clearly to all neighbors in the area, not just biological relatives. The author summarizes these discoveries as follows:

Plants could therefore be considered to have dialects and to be aware of contexts enough to know when to use them (…). They therefore remain in constant contact with their environment and with the changing status of threats. Their communication is not basic at all, but complex and layered, with multiple meanings.

How do plants react to touch?

In this context, Zoë Schlanger brings up the topic of electricity and wonders what happens when it disappears. The results of a surprising experiment provide the answer: narcosis affects plants almost identically to humans – it deprives them of their response to stimuli. Scientists subjected flycatchers to general anesthesia and it turned out that in this state they stopped responding to touch, i.e. they did not close on the prey, no matter how many sensory hairs were irritated. Fifteen minutes after the anesthesia wore off, everything returned to normal. A similar effect was observed in the basal mimosa.

The fact that touch is of great importance to plants was also confirmed by Mordecai Jaffe’s research. He showed that when touched, the plant can shorten, change its structure or become more flexible. In nature, this is a skill worth its weight in gold, as it allows you to survive storms or avoid damage caused by moving animals.

How did scientists prove that plants hear?

Researchers Heidi Appel and Rex Cocroft wondered whether plants could “hear” their attackers. To check this, they conducted an experiment with radish and the cabbage moth caterpillar. In the study, they used piezoelectric guitar transducers that were tuned to the exact frequency of vibrations caused by the insect’s chewing. After recording these vibrations, they were played back to the plants and their response was examined.

It turned out that the radish can hear. Moreover, trials with other sounds – such as the mating songs of aphids – did not elicit any response. The plant reacted specifically and only to the sound of the pest that actually threatened it. As the author emphasizes:

(…) what they discovered was not just a small brick. This was proof that plants really could hear – in their own earless way. For them, sound is pure vibration. And they can react when they sense a vibration that they know may be emitted by something that threatens them.

What do we really owe to plants?

Taking into account the reliable evidence on which Zoë Schlanger’s book is based, we should stop looking at the greenery around us only as a decorative background. This is not a nameless mass, but “thousands of distinct and fragile individuals, as different from each other as a trout is from a lion.” The author of “Light Eaters” cites, among others, biology lessons by Simon Gilroy, who made her students aware of a fundamental truth: it was plants that transformed the Earth’s atmosphere from a mixture of poisonous gases into air saturated with oxygen.

This shows a deep connection: the human body is made of sugars produced in the process of photosynthesis. Plants produce oxygen and organic matter, which becomes our food. It is thanks to them that we breathe and live. Understanding their role should lead us from disregard to deep respect:

The well-being of the world’s plant communities now depends on human attitudes towards them. When we treat plants as beings, we can see them on their own terms. Perhaps we could also look at them with this special admiration, but as a larger whole? Their biological value lies in their function as members of the interconnected communities – rich and full of interspecies interactions – that sustain the world: the world of which we are all a part.

Zoë Schlanger decided that these extraordinary stories were too important to remain only in the world of hermetic scientific debates. Her book “Light Eaters. How the mysterious intelligence of plants changes our understanding of life on Earth” opens a gate to a completely new reality for readers. If you decide to go through it, you will discover a world that can revolutionize your everyday life.