Roger: 0:02

Talking Trees with Lily and Jad. Welcome to another episode of Talking Trees. Today we'll explore the world of tree morphology and physiology and how it shapes tree management practices. We'll dive into the architectural models of trees and their growth strategies, uncovering phenomena like pruning responses, subtractive growth and how cavities impact tree stability. We'll also examine the different stages of tree development and their influence on morphology, physiology, stress responses and mechanical stability. It's a deep dive into the science behind managing trees for health and longevity. Let's get started and longevity.

Jad: 0:49

Let's get started. Hey everyone, welcome to another deep dive. You know we're always talking about how important it is to keep learning and growing as arborists, absolutely. And today we're diving into some research that really challenges the way we think about trees.

Lilly: 1:00

Yeah, this is going to be good.

Jad: 1:01

It's all about this concept called morphophysiology.

Lilly: 1:05

Morphophysiology.

Jad: 1:06

It's kind of mouthful, but basically it's about how a tree's form and function are completely intertwined. Right, we're going to be exploring how understanding this concept can completely change the way we approach tree care.

Lilly: 1:19

Especially for those old majestic veteran trees that we all love.

Jad: 1:23

Now, I know some of you might be thinking.

Lilly: 1:25

Oh no, not another theory.

Jad: 1:26

But trust me, this is more than just academic jargon.

Lilly: 1:28

It's really practical stuff.

Jad: 1:30

We're going to be talking about the work of a researcher named Giovanni Morelli.

Lilly: 1:35

Well, morelli's been studying trees for decades. He's really focused on those ancient veteran trees that have survived for centuries, but what's cool is that his findings apply to trees of all ages. It's all about understanding the fundamental principles of how they grow, how they develop, how they respond to their environment.

Jad: 1:54

So it's like understanding the language of trees.

Lilly: 1:55

Exactly.

Jad: 1:56

Okay, I'm intrigued. Let's break this down. What exactly is morphophysiology? I mean, how would you explain it to someone who's never heard of it before?

Lilly: 2:05

Okay, so morphophysiology? It's basically the study of how a tree's shape, its form and its functions are totally connected.

Jad: 2:13

So it's not just what we see on the outside.

Lilly: 2:15

Right. We have to understand what's going on inside the tree throughout its entire life.

Jad: 2:19

Okay, so it's like we're looking at the tree as a whole system, not just a collection of parts.

Lilly: 2:23

Exactly, and that's where things start to get really interesting, because when we start to think about trees in this way, it changes our whole perspective on tree care.

Jad: 2:32

Okay, I'm starting to see how this could be a game changer. So instead of just looking for defects or damage, we're trying to understand how the tree is working as a whole organism.

Lilly: 2:41

Right, and that can lead to some pretty different decisions about how we manage trees.

Jad: 2:45

Can you give us an example Like how would this more for physiology thing actually change the way we approach pruning or cabling or even removal?

Lilly: 2:54

Sure. So let's say you're looking at a tree with a big cavity in its trunk.

Jad: 2:58

Okay, I've seen plenty of those.

Lilly: 2:59

Now, traditionally we might look at that cavity and think oh no, this tree is structurally compromised, we need to cable it or maybe even remove it.

Jad: 3:08

Yeah, that's kind of the default thinking isn't it?

Lilly: 3:13

But Morelli's research shows that trees are much more adaptable than we give them credit for. They can actually compartmentalize decay and create internal support structures that allow them to remain stable even with significant cavities.

Jad: 3:22

Wow, so that cavity might not be as big a deal as we thought.

Lilly: 3:25

Exactly, and if we remove that tree, we might be losing a valuable part of the ecosystem, even if it looked a little ruck around the edges.

Jad: 3:32

Okay, so we need to be more careful about assuming that a cavity or a lost limb automatically means a tree is doomed.

Lilly: 3:39

Absolutely, Especially with those veteran trees. They've had centuries to develop these incredible internal structures that allow them to reintegrate and stay stable.

Jad: 3:49

This is really blowing my mind. So we can't just rely on visual inspection to assess a tree's health and stability?

Lilly: 3:56

Right, we need to be looking deeper. We need to be using tools like sonic tomography to actually see what's going on inside the tree, and that information can help us make more informed decisions about how to manage that tree.

Jad: 4:07

Wow, I'm starting to see how this morphophysiology thing can really change the game for arborists.

Lilly: 4:13

It definitely requires a shift in thinking, but I think it's a shift that's long overdue.

Jad: 4:17

Okay, so we've talked about how this new understanding can change the way we approach things like pruning and cabling, but there's got to be more to this morphophysiology thing, right.

Lilly: 4:28

Oh yeah, We've only scratched the surface.

Jad: 4:29

Like what else do we need to know?

Lilly: 4:31

Well, one of Morelli's most fascinating findings is this idea that trees are more like colonies than single organisms.

Jad: 4:38

Colonies. What do you mean?

Lilly: 4:39

He calls this concept modularity.

Jad: 4:42

Modularity. Ok, this is getting interesting.

Lilly: 4:45

Imagine a tree's crown as a collection of branches, each with its own leaves, buzz and support structure.

Jad: 4:52

Oh, I can picture that.

Lilly: 4:53

Each of these branches is like a module, a repeating unit.

Jad: 4:56

Like a building block.

Lilly: 4:57

Exactly, and within each module you see the same basic components repeating over and over.

Jad: 5:03

So the tree is like a bunch of smaller trees all living together.

Lilly: 5:05

It's kind of like that, and this modularity is what gives trees their incredible resilience.

Jad: 5:10

Because if one module gets damaged, the others can keep going.

Lilly: 5:14

Right, it's like having multiple backup systems built in. Parts can be lost without the whole organism dying.

Jad: 5:19

Okay, that makes sense, but how does this idea of modularity actually change the way we approach tree care?

Lilly: 5:25

Well, for one thing, it makes us realize that removing one module might not be as detrimental as we traditionally thought.

Jad: 5:31

Really you mean like pruning a branch?

Lilly: 5:33

Exactly. In fact, removing a module can actually stimulate the growth of other modules, making the tree stronger and more resilient overall.

Jad: 5:41

So sometimes it's actually beneficial to remove parts of a tree.

Lilly: 5:45

Exactly, it's like a controlled burn in a forest. It can help to prevent larger, more destructive fires in the long run.

Jad: 5:52

Okay, that's a really interesting way to think about it, yeah.

Lilly: 6:01

So we need to be more careful about assuming that every branch is essential to the tree's survival Right. We need to think about how removing a branch will affect the tree's overall structure and energy balance.

Jad: 6:06

It's like we need to be more strategic with our pruning decisions. Exactly this is so cool. It's like we're learning a whole new language for understanding trees.

Lilly: 6:13

It is, and the more we learn, the more we realize how amazing these organisms really are.

Jad: 6:19

Okay, my mind is officially blown, but I have a feeling we're just getting started.

Lilly: 6:23

Oh yeah, we've only just begun to explore the amazing world of morphophysiology. Well, think about this. We've been talking about how a tree's form and function are connected.

Jad: 6:33

Right, like how its shape reflects its adaptations and all that.

Lilly: 6:36

Exactly, but it's not just about the overall shape, it's also about how the tree changes throughout its life.

Jad: 6:42

Okay, so we're talking about the tree's life cycle now.

Lilly: 6:44

Right Morelli's research shows that each stage of a tree's life has unique characteristics.

Jad: 6:50

So, like, a baby tree is going to have different needs and priorities than a mature tree.

Lilly: 6:54

Exactly, and those differences are reflected in the tree's morphology, its form and its physiology, its internal processes.

Jad: 7:02

Okay, I'm following you, so walk us through these different stages. What are we looking for at each stage of the tree's life?

Lilly: 7:08

All right, well, morelli identifies five main phases.

Jad: 7:12

Five. Okay, lay them on me.

Lilly: 7:14

You've got the infant phase, the young phase, the adult phase, the mature phase and the senescent phase.

Jad: 7:20

Senescent. What does that mean?

Lilly: 7:21

That's the stage of decline, basically the tree's twilight years.

Jad: 7:25

Okay, so kind of like the human life cycle we go from babies to seniors.

Lilly: 7:29

It's a good analogy, but remember we're not just talking about size here. A giant tree isn't automatically a mature tree. It's about the tree's physiology, its internal processes, how well it can compartmentalize decay, its overall resilience.

Jad: 7:44

Okay, so it's about the tree's inner workings, not just its outward appearance. All right, so let's start at the beginning. What's happening inside a baby tree during that infant phase?

Lilly: 7:55

Well, during the infant phase it's all about rapid growth, putting on height, getting those roots established. The tree is really dependent on hormones to drive its upward growth and branching patterns.

Jad: 8:05

So it's like a teenager just trying to grow up fast.

Lilly: 8:07

Exactly, it's all about establishing itself in the world.

Jad: 8:10

OK what happens next?

Lilly: 8:11

Then comes the young phase. This is when things start to get more complex. Young phase this is when things start to get more complex. The trunk gets thicker, branches become more established and the crown starts to develop its characteristic shape.

Jad: 8:22

And I'm guessing we see more of that modularity coming into play here.

Lilly: 8:29

Absolutely. The young tree is adding more and more modules, creating that redundancy that makes it so resilient.

Jad: 8:32

So it's like it's building up its defenses, preparing for the challenges ahead.

Lilly: 8:34

Right and it's starting to lay down the foundation for heartwood formation.

Jad: 8:38

Heartwood. That's the strong inner core of the tree right.

Lilly: 8:40

Exactly, it's the tree's support system. It gives the tree its strength and stability.

Jad: 8:46

Okay, so the young tree is getting ready for the long haul.

Lilly: 8:48

Exactly.

Jad: 8:49

What about the adult phase? What's the tree's main focus then?

Lilly: 8:52

In the adult phase, the tree is really hitting its stride. It's all about maximizing energy production through photosynthesis, developing a full crown and reproducing. This is often when trees reach their maximum height.

Jad: 9:05

So it's like the prime of life for a tree.

Lilly: 9:07

You could say that, and while outwardly it looks like it's all figured out, internally things are definitely changing.

Jad: 9:13

Like what's happening inside.

Lilly: 9:14

Well, a heartwood formation is in full swing and cavitation might be starting to occur in those older inner parts of the wood.

Jad: 9:21

Cavitation that sounds kind of scary.

Lilly: 9:24

It's not necessarily a bad thing. Remember we talked about how trees can compartmentalize decay. Well, cavitation is part of that process. It's how the tree adapts to the fact that its inner wood is no longer actively transporting water.

Jad: 9:37

So it's like the tree is pruning itself from the inside out.

Lilly: 9:39

It's a good way to think about it.

Jad: 9:41

Okay, so the adult tree is still changing and adapting, even though it looks pretty stable on the outside.

Lilly: 9:46

Absolutely.

Jad: 9:46

What about the mature phase? What happens then?

Lilly: 9:49

Things start to slow down a bit during the mature phase. Growth rates decrease and the tree's main focus shifts to maintaining its existing structure and defenses. You could say it's settling into a comfortable middle age.

Jad: 10:02

Okay, I like that analogy and it's during this phase that we often see those really dramatic examples of reiteration and compartmentalization. Right, those veteran trees that Morelli studies, they're usually in this mature phase where they've been through centuries of growth, adaptation and change.

Lilly: 10:18

Exactly, they're the survivors. They've seen it all and they've adapted to it all.

Jad: 10:22

Wow, that's pretty inspiring.

Lilly: 10:24

And then, finally, we have the senescent phase. This is the stage of decline, where the tree's overall vitality is decreasing, growth slows down significantly and it becomes more vulnerable to pests, diseases and environmental stresses.

Jad: 10:37

So it's like the twilight years, but you're telling me, even then, these trees can still surprise us.

Lilly: 10:43

Even in senescence, trees can show remarkable resilience. Remember those cambial columns and bridges we discussed. They can help a tree stay strong even as its outer layers decay.

Jad: 10:54

So even a tree that's in decline can still have a lot to teach us.

Lilly: 10:57

Absolutely Every tree has a story to tell and every stage of a tree's life is valuable.

Jad: 11:01

This whole concept of a tree's life cycle is fascinating, but I'm curious how does this knowledge actually change what we do as arborists?

Lilly: 11:08

Well, for one thing, it encourages us to be much more conservative in how we manage trees. What?

Jad: 11:13

do you?

Lilly: 11:13

mean we need to remember that trees have been adapting and thriving for millions of years. They're incredibly resilient organisms. Our goal should be to support their natural processes as much as possible.

Jad: 11:25

So we're not just rushing in with a chainsaw at the first sign of trouble.

Lilly: 11:28

Exactly. We need to take a step back, assess the situation carefully and consider the long-term impact of our actions.

Jad: 11:36

It's like we need to be more thoughtful and less reactive in our approach.

Lilly: 11:39

Right Morphophysiology helps us understand what we might perceive as a problem could actually be an adaptation that's helping the tree survive.

Jad: 11:47

Can you give us some specific examples of how this might change our approach? Let's start with pruning. How does this knowledge impact those decisions?

Lilly: 11:55

Well, traditional pruning often focuses on removing dead, diseased or damaged branches, but now we're understanding that we need to be much more selective.

Jad: 12:03

What do you mean?

Lilly: 12:04

We need to think about how removing a branch will affect the tree's overall structure and energy balance. For example, taking out a large live branch might seem like a good way to reduce weight and wind resistance, but but there could be consequences we didn't consider before. Right. If that branch is part of a cambial column or bridge system, removing it could actually make the tree weaker. We also need to remember that leaves are the tree's food factories. If we remove too much foliage, we reduce its ability to photosynthesize and produce energy.

Jad: 12:36

So pruning decisions need to be made on a case-by-case basis, taking all these factors into account. What about cabling and bracing? How does this new understanding change those decisions?

Lilly: 12:46

In the past, cabling and bracing were often used to try and prolong the life of a tree that was already in decline, but now we're seeing that we should be more cautious about using these techniques, especially on veteran trees.

Jad: 12:57

Why is that?

Lilly: 12:58

Because cabling and bracing can sometimes interfere with a tree's natural adaptations. Remember they're constantly adjusting their growth, their wood density, their support structures in response to external stresses.

Jad: 13:09

So by adding artificial supports, we could actually be preventing the tree from strengthening itself.

Lilly: 13:14

Exactly. It's like putting a cast on a broken bone. It's necessary for healing, but if you leave it on too long the muscles can weaken. Similarly, over-relying on cabling and bracing might weaken a tree in the long run.

Jad: 13:27

That's a really interesting point. So how do we know when cabling and bracing are truly appropriate?

Lilly: 13:32

It comes down to a thorough assessment and understanding the tree's morphophysiology. We need to ask ourselves is the tree actively compartmentalizing decay? Is it developing those cambial columns and bridges? Is it still capable of adapting to changing conditions?

Jad: 13:48

If the answer is yes, then we might consider cabling and bracing as a temporary measure to give the tree more time to adapt.

Lilly: 13:54

Right, but if the tree is truly declining and can't adapt effectively, then we might need to consider removal, even though that's always a tough call. It is. But even then, Morelli's work gives us a new perspective on removal. He reminds us that even in death, a tree can still play a valuable role in the ecosystem.

Jad: 14:10

Right, we talked about those standing dead trees and snags, providing habitat and contributing to the forest ecosystem.

Lilly: 14:15

Right.

Jad: 14:16

It's like a whole other chapter of the tree's life cycle.

Lilly: 14:18

Exactly, and Morelli emphasizes that we need to see trees as part of a larger system, not just as individual entities. Now, you mentioned polyarchical trees earlier. These are the really complex ones that Morelli has developed a specific framework for assessing.

Jad: 14:33

Yes, Tell me more about those polyarchical trees. Those with multiple trunks seem like they would be extra challenging to evaluate. Where do you even begin? They are incredibly complex. Both those with multiple trunks seem like they would be extra challenging to evaluate. Where do you even begin?

Lilly: 14:42

They are incredibly complex, both internally and externally. That's why traditional assessment methods might not cut it for these trees. Think about it Multiple trunks, each with its own growth history, decay patterns and load-bearing capacity. It gets complicated quickly.

Jad: 14:56

So how do we make sense of all that? Does Morelli offer any guidance?

Lilly: 14:59

He does. He uses a combination of visual inspection with those high-tech tools we talked about sonic tomography and pulling tests but he stresses the importance of understanding the tree's morphophysiological history, those processes of reiteration and compartmentalization that have shaped it over time.

Jad: 15:14

It's like we're piecing together a puzzle, looking for clues in the tree's form to understand its past and predict its future. Well, this has been an incredible journey, so what's?

Lilly: 15:27

the main takeaway here? What do we want our listeners to remember? I think the most important thing to remember is that trees are much more complex and interconnected than we ever imagined. They're not just these static objects. They're dynamic living organisms that are constantly adapting and responding to their environment.

Jad: 15:41

And if we want to take care of them properly, we need to start thinking like they do.

Lilly: 15:44

Exactly. We need to understand their language, we need to respect their complexity.

Jad: 15:49

That's a great message to end on. Thank you so much for sharing your expertise with us today.

Lilly: 15:54

It's been my pleasure.

Jad: 15:55

And thank you to all of our listeners for joining us on this deep dive into the world of morphophysiology. We hope you learned something new and we hope you're inspired to go out and see trees in a whole new light.

Roger: 16:10

That's it for today's episode of Talking Trees. We hope you enjoyed this journey into the intricate relationship between tree morphology, physiology and management practices. Intricate relationship between tree morphology, physiology and management practices. If you found this episode insightful, be sure to leave a review and share it with others passionate about arboriculture, join us next time as we continue exploring the science and art of tree care. Until then, stay curious and keep nurturing the world around you.