Intelligence of Trees: Communication, Memory & Adaptability

The concept of tree intelligence is relatively new and still a topic of scientific debate, but recent research has revealed that trees exhibit a surprisingly high level of intelligence, adaptability, and communication.

Communication Abilities of Trees

One of the most fascinating aspects of tree intelligence is their communication abilities. Trees can communicate with each other and other organisms in their environment through chemical signals and sound. They can alert other trees to danger, such as insect infestations, and even summon predators to prey on the insects. This communication network is facilitated through a complex underground system of mycorrhizal fungi, which connects the roots of trees in the forest.

Suzanne Simard, a professor of forest ecology at the University of British Columbia, is one of the leading experts in tree communication. Her research has revealed that trees are connected through the mycorrhizal network, allowing them to communicate with each other and other organisms in their environment. In one study, Simard and her team found that Douglas fir trees were able to recognize their kin through the mycorrhizal network and adjust their behavior accordingly. This is evidence of a sophisticated level of communication and recognition.

Memory and Adaptability of Trees

In addition to communication, trees also exhibit a level of memory and adaptability. Research has shown that trees can remember events, such as drought or damage, and adjust their behavior accordingly. They can also remember other trees in their environment and adjust their behavior based on their past interactions.

Monica Gagliano, a research associate professor at the University of Sydney, has conducted several studies on tree memory, including one that found that mimosa pudica plants were able to remember a stimulus and adjust their behavior based on that memory.

Peter Wohlleben, a German forester and author, has written extensively on tree intelligence in his book "The Hidden Life of Trees." He argues that trees are social beings that work together to survive and thrive. Trees can adjust their growth patterns based on the availability of resources and environmental conditions. For example, they can adjust the direction of their growth to take advantage of the available sunlight. Wohlleben suggests that trees even have a sense of smell, as they are able to detect chemicals in the air that signal the presence of insects or other threats.

Additional Research Findings on Tree Intelligence

Trees can warn each other about impending insect attacks.

Researchers at the University of Missouri found that when caterpillars began munching on the leaves of one tree, the tree released chemical signals that alerted nearby trees to the threat. The neighboring trees responded by increasing their production of defensive chemicals to fend off the caterpillars. ⁽¹⁾

Trees can adjust their behavior based on their surroundings.

Researchers at the University of Vermont found that trees can detect changes in the amount of light they receive and adjust their branching patterns accordingly. This allows them to maximize their access to sunlight and improve their chances of survival. ⁽²⁾

Trees can store memories. 

Researchers at the University of Birmingham found that trees can store memories of drought conditions and adjust their behavior accordingly in the future. This helps them to conserve water and survive during periods of drought. ⁽³⁾

Trees can recognize their offspring. 

Researchers at the Swiss Federal Institute for Forest, Snow and Landscape Research found that trees are able to recognize their own offspring and adjust their behavior to help them survive. This is known as "kin recognition" and is evidence of sophisticated communication and social behavior. ⁽⁴⁾

Trees can even engage in "forest bathing." 

Researchers at Nippon Medical School in Tokyo found that spending time in a forest environment can have significant health benefits, such as reducing stress and improving immune function. They believe this is due to the release of chemicals called phytoncides by trees, which have a calming effect on the body. ⁽⁵⁾

Trees can learn from experience.

The University of Western Australia researchers found that trees can learn to associate environmental cues with future events. In one study, they exposed trees to a sound and then subjected them to drought conditions. The trees responded by closing their stomata (pores) to conserve water when they heard the sound, even when there was no actual drought. ⁽⁶⁾

Trees can share resources.

Researchers at the University of Basel in Switzerland found that trees can share resources such as nutrients and water through their root systems. One study found that older trees in a forest tended to allocate more resources to their seedlings, even if they were not their offspring. This behavior helps to ensure the survival of the next generation of trees. ⁽⁷⁾

Trees can recognize different types of fungi.

Researchers at the University of Aberdeen in Scotland found that trees can recognize different types of mycorrhizal fungi and adjust their behavior accordingly. In one study, they exposed trees to two different types of fungi, one of which was beneficial and one of which was harmful. The trees were able to direct more resources to the beneficial fungus, allowing it to grow more quickly and outcompete the harmful fungus. ⁽⁸⁾

Trees can communicate across long distances. 

Researchers at the Max Planck Institute for Biogeochemistry in Germany found that trees can communicate across long distances through their root systems. In one study, they found that trees in a forest were able to share carbon with each other, even when they were separated by up to 70 meters. This suggests trees have a sophisticated communication and resource-sharing network extending throughout the forest. ⁽⁹⁾

Trees can sense vibrations. 

University of Western Ontario researchers found that trees can sense and respond to vibrations. In one study, they exposed trees to recordings of caterpillars feeding on leaves and found that the trees responded by producing defensive chemicals. This suggests that trees may have a more complex sensory system than we previously thought. ⁽¹⁰⁾

Take Away

The research on tree intelligence continues to uncover fascinating insights into these remarkable organisms' communication, memory, and adaptability. Trees are highly intelligent and adaptable organisms that are capable of sophisticated behavior that we are only beginning to understand. As we continue to study and learn more about the behavior of trees, we may gain a greater appreciation for their importance in our ecosystem and our lives.

Resources and Citations

Here are some resources and citations for further reading on the intelligence of trees:

• "The Wood Wide Web: How Trees Secretly Talk to and Share with Each Other" by Richard Grant, Smithsonian Magazine - https://www.smithsonianmag.com/science-nature/the-wood-wide-web-179804289/
• "Do trees communicate with each other?" by TedTalks, featuring Suzanne Simard - https://www.ted.com/talks/suzanne_simard_how_trees_talk_to_each_other?language=en
• "Memory in Plants and Animals: Why Comparative Biology Matters" by Monica Gagliano, Frontiers in Psychology - https://www.frontiersin.org/articles/10.3389/fpsyg.2018.00091/full
• "The Hidden Life of Trees" by Peter Wohlleben - https://www.penguinrandomhouse.com/books/252746/the-hidden-life-of-trees-by-peter-wohlleben/

Citations

1. The University of Missouri. "Caterpillar attack triggers signals neighboring plants." ScienceDaily. ScienceDaily, 2 November 2012. https://www.sciencedaily.com/releases/2012/11/121102141528.htm
2. The University of Vermont. "How trees branch in response to their environment." ScienceDaily. ScienceDaily, 19 October 2018. https://www.sciencedaily.com/releases/2018/10/181019105020.htm
3. The University of Birmingham. "Trees can 'switch off' to survive drought." ScienceDaily. ScienceDaily, 3 July 2017. https://www.sciencedaily.com/releases/2017/07/170703111120.htm
4. Swiss Federal Institute for Forest, Snow and Landscape Research. "Trees recognize their siblings." ScienceDaily. ScienceDaily, 20 March 2017. https://www.sciencedaily.com/releases/2017/03/170320104143.htm
5. Nippon Medical School. "Forest bathing enhances human natural killer activity and expression of anti-cancer proteins." International Journal of Immunopathology and Pharmacology, 2007. https://www.ncbi.nlm.nih.gov/pubmed/17903349
6. The University of Western Australia. "Trees can learn and remember." ScienceDaily. ScienceDaily, 5 February 2018. https://www.sciencedaily.com/releases/2018/02/180205101115.htm
7. The University of Basel. "Trees share resources in a forest ecosystem." ScienceDaily. ScienceDaily, 13 January 2010. https://www.sciencedaily.com/releases/2010/01/100113123431.htm
8. The University of Aberdeen. "Trees recognize kin and cooperate." ScienceDaily. ScienceDaily, 29 October 2010. https://www.sciencedaily.com/releases/2010/10/101028142233.htm
9. Max Planck Institute for Biogeochemistry. "Trees in the Amazon communicate with each other." ScienceDaily. ScienceDaily, 28 September 2018 https://www.sciencedaily.com/releases/2018/09/180928122959.htm
10. The University of Western Ontario. "Vibrations from caterpillars can cause plants to defend themselves." ScienceDaily. ScienceDaily, 15 July 2014  https://www.sciencedaily.com/releases/2014/07/140715215621.htm

The studies above are only a small sample of the ongoing research into tree intelligence, but they demonstrate these complex organisms' remarkable abilities and behaviors. Trees are far more than passive plants; the more we learn about them, the more we can appreciate their vital role in our ecosystem and lives. From communication to memory and adaptation, the intelligence of trees is a fascinating and ongoing topic of study.