Alex Shigo

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 .

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 .

Yes .

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

Of course .

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

Absolutely .

He's often called the father of modern arboriculture .

He is .

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

Yeah .

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 .

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 .

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

Yes .

Compartmentalization of decay in trees .

Compartmentalization of decay in trees .

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

Right .

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

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

Okay .

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

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

Yes , it is .

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

Right .

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

That's right .

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

Yep .

Slowing the inward spread .

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

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 .

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 .

Yeah .

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

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 .

Right .

Understanding their biology and respecting their natural defenses .

He believed that by truly

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

Absolutely .

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

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

Yeah .

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

Yeah .

And made them more susceptible to decay .

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 .

He really hit a nerve with that one .

He did . Shigo was a champion for trees , advocating

Yes .

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

Right .

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 .

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

Yeah .

He really laid the foundation for modern arboriculture .

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 .

Absolutely .

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

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 .

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

Exactly .

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 .

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 .

He even challenged the traditional view of heartwood .

He did .

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

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 .

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

Yeah .

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 .

Absolutely .

And he debunked a lot of misconceptions about heart rot .

He did .

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

Right .

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 .

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 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 .

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 .

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 .

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 .

It is .

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

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 .

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 .