Roger: 0:02

Talking Trees with Lillian Jadd. Welcome to Talking Trees. Today we explore the life and work of Dr Alex Shigo, the pioneer of modern arboriculture. Shigo revolutionized tree care with his concept of CODIT Compartmentalization of Decay in Trees shifting how we approach tree biology and management. We'll dive into his biography, his contributions to the field and insights from a video where Shigo himself discusses Cotted and Tree Biology. Get ready to learn about Shigo's lasting impact on arboriculture.

Jad: 0:44

All right, let's jump into our deep dive today, and you know, I think, we're going to explore the work of a true legend in our field, dr Alex Shigo.

Lilly: 0:53

Yes.

Jad: 0:54

Now as a professional arborist, you know. I'm sure you've heard the name.

Lilly: 0:59

Of course.

Jad: 0:59

You're familiar with some of his revolutionary ideas about tree care.

Lilly: 1:03

Absolutely.

Jad: 1:05

He's often called the father of modern arboriculture.

Lilly: 1:08

He is.

Jad: 1:09

And for good reason. His research completely transformed the way we approach tree care.

Lilly: 1:15

Yeah.

Jad: 1:16

We're talking about a time when pruning practices were more about aesthetics than tree health. Right, and the invention of the one-man chainsaw oh yeah, gave Shigo a new tool for understanding trees.

Lilly: 1:26

That's right. Before Shigo, a lot of our knowledge about tree decay came from studying cross sections of wood. Yeah, but with the chainsaw he could create these incredible longitudinal sections, like slicing a loaf of bread lengthwise. Suddenly, you could see the pathways of decay in 3D tracing how it spreads within the tree.

Jad: 1:44

And that's where his groundbreaking discovery of Cody comes in.

Lilly: 1:47

Yes.

Jad: 1:48

Compartmentalization of decay in trees.

Lilly: 1:51

Compartmentalization of decay in trees.

Jad: 1:53

He realized that trees don't heal wounds in the same way our skin does.

Lilly: 1:57

Right.

Jad: 1:57

They don't regenerate tissue, nope, they compartmentalize.

Lilly: 2:00

Think of it as the tree building internal walls to seal off the decay, preventing it from spreading further.

Jad: 2:07

Okay.

Lilly: 2:07

And each wall has a specific function in this defense mechanism.

Jad: 2:11

So let's break down these walls, because this is where it gets really interesting for us arborists.

Lilly: 2:15

Yes, it is.

Jad: 2:16

Wall one, the strongest forms right after injury, plugging the vascular system above and below the wound.

Lilly: 2:22

Right.

Jad: 2:22

What's so cool is that this wall prevents the vertical spread of decay.

Lilly: 2:26

That's right.

Jad: 2:27

Then you've got wall two, which runs perpendicular to the grain.

Lilly: 2:29

Yep.

Jad: 2:30

Slowing the inward spread.

Lilly: 2:31

It's like the tree is reinforcing its defenses, building a fortress against the invading decay.

Jad: 2:37

Wall three is fascinating because it's formed by the growth rings limiting the lateral spread. Right it's like the tree is creating a time capsule of the injury. Yeah, Limiting the lateral spread Right. It's like the tree is creating a time capsule of the injury. Yeah, and finally, wall four the barrier zone forms as new wood grows around the wound, completely isolating the damaged tissue.

Lilly: 2:53

Shigo's CODIT model showed us that trees are incredibly resilient, capable of fighting off decay and continuing to thrive even with significant internal damage.

Roger: 3:03

Yeah.

Lilly: 3:04

And his findings had huge implications for how we approach pruning.

Jad: 3:07

You can't talk about Shigo without talking about his famous phrase touch trees. Oh, yeah, he wasn't just talking about the physical act of touching a tree. It was about connecting with trees on a deeper level.

Lilly: 3:17

Right.

Jad: 3:17

Understanding their biology and respecting their natural defenses.

Lilly: 3:20

He believed that by truly understanding how trees work, we could provide better care and make more informed decisions about pruning, tree selection and even planting. He encouraged people to see trees as complex living beings, not just static objects in the landscape.

Jad: 3:35

It's like he was saying hey, if you're going to work with trees, you need to speak their language.

Lilly: 3:39

Absolutely.

Jad: 3:40

And Kodut was his way of translating that language for us.

Lilly: 3:43

Absolutely, and he wasn't afraid to challenge the status quo. Oh yeah, shiga was very vocal about his criticisms of common pruning practices.

Jad: 3:52

Yeah.

Lilly: 3:52

Like flush cuts that removed the branch collar. Uh-huh. He argued that these practices actually weakened trees.

Jad: 3:59

Yeah.

Lilly: 3:59

And made them more susceptible to decay.

Jad: 4:02

Remember that quote where he said scant attention is given to pruning as it affects the health of trees, while great attention has been given to pruning as it affects the desires of man.

Lilly: 4:12

He really hit a nerve with that one.

Jad: 4:14

He did. Shigo was a champion for trees, advocating for practices that prioritize their long-term health and well-being.

Lilly: 4:21

Yes.

Jad: 4:22

Even if it meant clashing with conventional wisdom or aesthetic preferences.

Lilly: 4:26

Right.

Jad: 4:27

His work really sparked a revolution in the arboriculture world it did, leading to the development of new pruning standards and techniques that are still used today.

Lilly: 4:36

It's amazing to think about how much our understanding of tree care has evolved thanks to Shigo's research.

Roger: 4:42

Yeah.

Lilly: 4:42

He really laid the foundation for modern arboriculture.

Jad: 4:46

He did. Yeah, his influence goes beyond just pruning. Yeah, shigo really opened our eyes up to the incredible complexity of trees as living organisms.

Lilly: 4:54

Absolutely.

Jad: 4:55

He talked about trees as generating systems Right, constantly growing and adapting to their environment.

Lilly: 5:00

It's a fascinating concept. He compared trees to the human body, always replacing old cells with new ones, constantly regenerating and renewing itself, and this understanding is crucial for us as arborists.

Jad: 5:12

Right, because it changes the way we think about wounds and decay.

Lilly: 5:15

Exactly.

Jad: 5:16

It's not just about removing the damaged parts. It's about understanding how the tree responds to those injuries and how we can support its natural defenses.

Lilly: 5:24

He was adamant that we stop seeing trees as static objects and start recognizing them as dynamic living systems constantly interacting with their surroundings, and this shift in perspective has had a profound impact on how we approach tree care.

Jad: 5:40

He even challenged the traditional view of heartwood.

Lilly: 5:42

He did.

Jad: 5:43

Which was often dismissed as just dead tissue Right. But Shigo argued that heartwood plays a crucial role in the tree's defense system.

Lilly: 5:51

He pointed out that heartwood is incredibly strong and resistant to decay. It provides structural support and acts as a barrier against further spread of decay. He even called it protection wood, emphasizing its vital function in the tree's overall health.

Jad: 6:07

I remember when I first learned about Shigo's ideas about heartwood.

Lilly: 6:11

Yeah.

Jad: 6:11

It was like a light bulb went off Right. Suddenly I realized we've been underestimating the complexity and resilience of trees for far too long.

Lilly: 6:19

Absolutely.

Jad: 6:20

And he debunked a lot of misconceptions about heart rot.

Lilly: 6:22

He did.

Jad: 6:23

He showed that the presence of decay in the heartwood doesn't necessarily mean the tree is doomed.

Lilly: 6:28

Right.

Jad: 6:28

In fact, trees have evolved to compartmentalize decay and continue thriving even with significant heartwood loss. That's right. He encouraged us to look beyond the visible symptoms and understand the tree's internal mechanisms for dealing with decay. He wanted us to see the bigger picture and appreciate the incredible adaptability of trees.

Lilly: 6:48

Shigo's work was groundbreaking, not just for its scientific rigor, but also for his ability to communicate complex ideas in a way that was accessible and engaging. He didn't just publish his findings in academic journals he wrote books, gave lectures and traveled the world sharing his passion for trees with anyone who would listen.

Jad: 7:07

He was a true advocate for trees, always pushing for better understanding and more informed tree care practices, and his legacy continues to inspire arborists around the world.

Lilly: 7:17

What's remarkable is that Shigo didn't just present his findings as absolute truths. He encouraged critical thinking and further research, urging others to build upon his work and continue exploring the mysteries of trees.

Jad: 7:29

He often said that we should never stop learning, that the world of trees is full of wonder and complexity, and that there's always something new to discover. He saw himself not as the final authority, but as a guide, inviting others to join him on this journey of discovery.

Lilly: 7:43

Yeah, and he gave us the tools to do just that. You know his coded model, his research on pruning, his insights into tree biology. His legacy is a call to action for all of us in the arboric culture field.

Jad: 7:54

It is.

Lilly: 7:55

It's a reminder to keep learning, keep asking questions and keep pushing the boundaries of our understanding of trees.

Jad: 8:00

So the next time you're out in the field working with trees, remember Dr Chigot and his message. Touch those trees, feel their energy and appreciate their complexity. Use his insights to make informed decisions and provide the best possible care for these magnificent living beings. For these magnificent living beings.

Roger: 8:21

Thank you for joining us on this episode of Talking Trees. Today we celebrated the groundbreaking contributions of Dr Alex Shigo his revolutionary cottage concept, his hands-on approach to understanding wood decay and his challenge to traditional arboricultural practices. We hope his legacy inspires you to look deeper into the science and art of tree care. Until next time, keep touching the roots of nature.