How trees talk to each other | Suzanne Simard | Summary and Q&A

TL;DR

Forests are more than just a collection of trees - they are complex systems with interconnected networks that allow trees to communicate and cooperate.

Key Insights

• 👻 Forests are complex systems with interconnected networks that allow trees to communicate and cooperate.
• 💁 Mycorrhizal networks formed by fungal threads connect trees of different species and facilitate the exchange of carbon and nutrients.
• 😉 Mother trees play a crucial role in nurturing their kin through increased carbon and nutrient transfer in mycorrhizal networks.

Transcript

Imagine you're walking through a forest. I'm guessing you're thinking of a collection of trees, what we foresters call a stand, with their rugged stems and their beautiful crowns. Yes, trees are the foundation of forests, but a forest is much more than what you see, and today I want to change the way you think about forests. You see, underground th... Read More

Questions & Answers

Q: How do trees communicate with each other?

Trees communicate through mycorrhizal networks, where fungal threads form a symbiotic relationship with tree roots, enabling the exchange of carbon, nutrients, defense signals, and more.

Q: Can trees recognize their own kin?

Yes, trees can recognize their kin. Mother trees send more carbon and nutrients to their kin through mycorrhizal networks, reducing root competition and increasing seedling survival.

Q: How can we reinforce forests to deal with climate change?

We can reinforce forests by promoting local involvement in forest stewardship, saving old-growth forests, preserving mother trees and mycorrhizal networks during logging, and promoting diversity in tree species and genotypes during forest regeneration.

Q: Why are forests vulnerable to disturbances?

Forests are vulnerable to disturbances like clear-cut logging and insect outbreaks because the removal of hub trees, which are important for network connectivity, can lead to the collapse of the entire system.

Q: How do trees communicate with each other?

Trees communicate through mycorrhizal networks, where fungal threads form a symbiotic relationship with tree roots, enabling the exchange of carbon, nutrients, defense signals, and more.

More Insights

• Forests are complex systems with interconnected networks that allow trees to communicate and cooperate.

• Mycorrhizal networks formed by fungal threads connect trees of different species and facilitate the exchange of carbon and nutrients.

• Mother trees play a crucial role in nurturing their kin through increased carbon and nutrient transfer in mycorrhizal networks.

• Forests need to be managed with consideration for local conditions, preservation of old-growth forests, conservation of mother trees and mycorrhizal networks, and regeneration with diverse tree species and genotypes to enhance their resilience.

Summary

In this video, the speaker talks about the interconnectedness and communication among trees in a forest. She shares her personal story of growing up in the forests of British Columbia and her curiosity about the roots and soil that form the foundation of the forest. Despite facing skepticism and lack of funding, she conducted experiments that proved the existence of a belowground communication network between trees. This network, facilitated by mycorrhizal fungi, allows trees to share carbon, nutrients, defense signals, and wisdom with each other. The speaker emphasizes the importance of understanding and protecting this complex system in order to practice more sustainable forestry.

Questions & Answers

Q: How did the speaker's upbringing and experiences in the forest shape her interest in studying trees?

The speaker grew up in the forests of British Columbia, where her grandfather, a horse logger, taught her about the quiet and cohesive ways of the woods. She became fascinated with the roots and soil of the forest when she helped her grandfather rescue their dog from a pit and realized that this biodiversity was the foundation of the forest.

Q: What sparked the speaker's interest in studying the underground connections between trees?

While studying forestry and working alongside commercial harvesters, the speaker became conflicted by the extensive clear-cutting and destruction of forests. She wanted to find a more sustainable approach to forestry and believed that there might be communication happening between trees belowground. The discovery of communication between pine seedling roots in the lab inspired her to investigate if this occurs in real forests.

Q: How did the speaker conduct her experiments to study the communication between trees?

The speaker conducted her experiments in the forest by growing replicates of three species: paper birch, Douglas fir, and western red cedar. She used plastic bags and syringes to inject isotopes of carbon dioxide gas into the bags covering the trees. Through isotope tracing, she could track the movement of carbon between the trees and determine if there was communication happening between them.

Q: What did the speaker discover through her experiments about the communication between trees?

The speaker found that paper birch and Douglas fir were engaged in a two-way conversation, exchanging carbon belowground through the mycorrhizal network. The birch would send more carbon to the fir, especially when the fir was shaded, and the fir would reciprocate when the birch was leafless. However, the western red cedar was in its own separate world and not connected to the communication network.

Q: How are mycorrhizal networks formed in the forest?

Mycorrhizal networks are formed when the fungal threads, called mycelium, infect and colonize the roots of trees and plants. These mycelium networks trade carbon for nutrients with the trees and extend through the soil, connecting different individuals in the forest. This network acts like the Internet of the forest, allowing for communication and nutrient exchange.

Q: What role do hub trees play in the mycorrhizal network?

Hub trees, also known as mother trees, are big old trees that act as the busiest nodes in the mycorrhizal network. They nurture the young seedlings growing in the understory and send them more carbon belowground through the mycorrhizal network. The mother trees recognize their kin and provide them with extra support and resources.

Q: How do mother trees help increase the resilience of the whole forest community?

Mother trees not only provide carbon to seedlings in the understory but also share defense signals and wisdom. When mother trees are injured or dying, they send messages through the mycorrhizal network to neighboring seedlings. This transfer of information increases the resistance of the seedlings to future stresses and helps the entire forest community become more resilient.

Q: What are some of the challenges and threats facing forests today?

Forests face challenges such as high-grade logging, clear-cut logging, and the planting of monocultures. These practices disrupt the complex systems and networks within the forest, making them vulnerable to natural disturbances and climate change. Forests are also threatened by deforestation rates, degradation of wildlife habitat, and the emission of greenhouse gases.

Q: What solutions does the speaker propose for reinforcing forests and helping them deal with climate change?

The speaker suggests four simple solutions. Firstly, she emphasizes the importance of local involvement and knowledge in forest stewardship. Secondly, she advocates for preserving old-growth forests as they contain valuable genes, mother trees, and mycorrhizal networks. Thirdly, she recommends conserving legacies during logging and ensuring the transfer of wisdom to the next generation of trees. Finally, she proposes regenerating forests with a diversity of species and genotypes, allowing for natural regeneration and giving nature the tools to self-heal.

Q: How does the speaker hope to change people's perception of forests?

The speaker wants to change the way people think about forests. She wants them to move away from viewing forests as a collection of individual trees competing with each other and instead see them as complex systems with interconnected networks of communication and cooperation. Understanding the resilience and vulnerability of forests can lead to more sustainable practices and a greater appreciation for their importance.

Q: What is the speaker's final message regarding forests?

The speaker urges people to recognize that forests are not simply a bunch of trees, but supercooperators. She highlights the enormous capacity of forests to self-heal and adapt to disturbances. By getting involved in local forest stewardship, preserving old-growth forests, conserving legacies, and promoting diversity in forest regeneration, individuals can help reinforce forests and enable them to deal with climate change.

Takeaways

Forests are complex systems with interconnected networks of communication and cooperation. Belowground, mycorrhizal networks formed by fungal threads play a vital role in facilitating communication between trees, allowing for the exchange of carbon, nutrients, defense signals, and wisdom. Mother trees, or hub trees, act as nurturing nodes within these networks, supporting the growth and resilience of the whole forest community. Understanding and protecting these complex systems is crucial for practicing sustainable forestry. Individuals can contribute by getting involved in local forest stewardship, preserving old-growth forests, conserving legacies, and promoting diversity in forest regeneration. By reinforcing forests, we can help them deal with climate change and ensure their long-term survival.

Summary & Key Takeaways

• Forests are not just what we see above ground, but also a vast network of connections underground.

• Mycorrhizal networks, formed by fungal threads, connect trees of different species and facilitate communication.

• Trees communicate through the exchange of carbon, nutrients, defense signals, and other information, leading to increased resilience and survival.