Introduction to Tree Growth Factors

Roger 0:02

Talking Trees with Lily and Jad. Welcome to Talking Trees, your daily journey into the science behind our green world. In today's episode, we explore the factors shaping plant and tree growth. Our first study examines the effects of Ascophyllum nodosum extract on various tree species, revealing short-term boosts in growth and root development at higher doses, though without lasting changes to improve transplant tolerance. Next, we dive into research on soil structure complexity, where a heterogeneous mix with macropores supports robust root growth in peas and barley, but not in Arabidopsis, highlighting the nuanced interplay between root architecture and soil dynamics. Join us as we unravel these insights and discover what truly nurtures our trees and plants.

Jad 0:57

Hey everyone and welcome to a deep dive specifically for you arborists out there.

Lilly 1:01

That's right.

Jad 1:01

We're going way past osmosis. You know, it's like just what it is in the textbook. Yeah, we're really going to dig into how it impacts the work that you do every day.

Lilly 1:11

Exactly.

Jad 1:11

From seed germination to root development, and even how seaweed extract. Can you know, really get down into how a tree functions?

Lilly 1:18

Yeah, it's fascinating stuff.

Jad 1:20

So get ready, because what we find out here could really change how you approach taking care of trees. So let's start with something that I think every arborist really cares about seed germination. Absolutely so. We've got this study by Common and their team and they tested seaweed extract on different tree species Right, and what they found with European beech or Phagos cephatica was really interesting.

Lilly 1:42

Yeah, they found a big increase in germination rates for the beach seeds when they were treated with the seaweed extract. But here's the thing Only the European beach seeds showed this big increase. The other species they tested didn't do the same thing.

Jad 1:58

So what's the deal with beach seeds? Is there something about how they're put together that makes them really take to that extract.

Seaweed Extract's Effect on Germination

Lilly 2:04

Well, it's a great question. Beech seeds have these large cotyledons, which are basically the seedling's energy reserves, and the study suggests that the seaweed extract might be helping those seeds access those reserves faster. They think it could be impacting the activity of an enzyme called alpha amamylase, which breaks down those stored nutrients.

Jad 2:26

Now I know that certain plant hormones like gibberellins, can also increase alpha-amylase activity. Exactly. But here's the weird thing the seaweed extract they used it didn't have any gibberellin, so how is it having this big effect on germination?

Lilly 2:40

That's the puzzle, and it just shows you how much we still need to learn about how plants and these extracts interact.

Jad 2:48

Right.

Lilly 2:49

There's something unique going on with how that seaweed extract is interacting with beach seeds on a cellular level. Wow, and researchers are definitely digging into that.

Jad 2:57

Yeah, it's like the seaweed extract is doing something special in those beach seeds.

Lilly 3:00

Yeah.

Jad 3:01

Boosting that germination? Yeah, but it's not using that typical gibberellin pathway. Nope, that's wild.

Lilly 3:06

It's a mystery for sure.

Root Architecture Across Tree Species

Jad 3:08

Let's move on to another part of tree care. That's really critical root development, uh-huh. This is where Kemin's team's study gets really interesting. Yeah, they looked at how root architecture is different between different tree species.

Lilly 3:18

Right.

Jad 3:19

And you know, as arborists, we're always thinking about roots.

Lilly 3:22

Of course.

Jad 3:23

But this research really takes our understanding to a whole new level.

Lilly 3:27

Absolutely, and they found that some species like common hawthorn or Crotagus monogena, they have what we call high specific root length, or SRL.

Jad 3:35

Right.

Lilly 3:36

And this basically means their roots are thinner and longer, so they can explore more soil.

Jad 3:41

Okay.

Lilly 3:41

Even if their root system isn't that massive overall.

Jad 3:44

Which makes sense. When you consider how hawthorn grows, right, you know it's a real early invader.

Lilly 3:49

Yeah.

Jad 3:49

Able to establish itself in new areas super quick, and those long exploratory roots really give it an advantage.

Lilly 3:56

Absolutely. It's all about that competitive edge and it just shows how a tree's root structure is totally tied to its role in the ecosystem.

Jad 4:04

Yeah, and then, on the other hand, you've got species like Phagos sylvotica.

Lilly 4:07

Uh-huh, our European beach friend again.

Jad 4:09

Yeah exactly.

Lilly 4:10

It develops denser roots with a lower SRL.

Jad 4:12

Right.

Lilly 4:13

And this strategy seems to work better in shallower organic soils. Okay, the kind of environment beach usually likes.

Jad 4:19

So different root strategies for different environments, exactly.

Lilly 4:21

It's all about adaptation, root strategies for different environments.

Soil Structure and Root Development

Jad 4:23

Exactly, it's all about adaptation, okay, so let's bring in another study now. Okay, that adds a really cool layer to what we're talking about.

Lilly 4:28

Yeah.

Jad 4:28

Giuliani and their team did some really interesting research on how soil structure impacts root development.

Lilly 4:36

Yeah, they created these artificial soil environments in the lab to really isolate the effects of what we call soil heterogeneity.

Jad 4:44

Okay.

Lilly 4:44

So imagine this they had these cores packed with either uniform, finely sieved soil, Okay. Or with clumps of soil.

Jad 4:51

All right.

Lilly 4:52

Kind of like what you'd see in a tilled seed bed.

Jad 4:54

Gotcha, I'm picturing it.

Lilly 4:55

Yeah.

Jad 4:55

So did they find that growing in that clumpy, heterogeneous soil actually helped root development? Well, I'm really curious.

Lilly 5:01

Well, it's not so simple for plants like peas and barley, which have pretty big root systems. They actually saw increased root length in that compacted, heterogeneous soil. It seems like those bigger roots were able to use those larger spaces between the soil clumps. Oh interesting, you know those macropores to navigate that denser soil more efficiently.

Jad 5:21

So it's like a good thing to have some variation in the soil structure.

Lilly 5:24

Exactly.

Jad 5:25

Especially for those species with the bigger roots.

Lilly 5:27

Yeah, it gives them more room to move.

Jad 5:28

Okay.

Lilly 5:29

But here's where it gets even more interesting.

Jad 5:31

Okay.

Lilly 5:32

They also tested a small plant called Arabidopsis Right, which has these super fine roots, and guess what? They found the opposite.

Jad 5:40

Oh, wow.

Lilly 5:41

Arabidopsis actually had shorter roots in that compacted, heterogeneous soil.

Jad 5:51

Huh, why would that be?

Lilly 5:51

Yeah Could it be that those tiny roots were just getting lost in those bigger pores. Yeah, that's a great point and it highlights something really important for you guys to think about.

Jad 5:56

What's that?

Lilly 5:56

The interplay between root size and soil pore structure Right. It's not just about having macropores, it's about having the right size macropores for the roots that are trying to grow.

Jad 6:06

Wow, that's a good point.

Lilly 6:07

Yeah.

Jad 6:08

So we're seeing that osmosis isn't just about water moving across a membrane.

Lilly 6:11

Right.

Jad 6:12

It's the engine driving how trees take up nutrients, how their roots develop and how they adapt to all these different soil environments.

Lilly 6:18

All connected.

Jad 6:19

Yeah, and that's just the tip of the iceberg. Exactly this seaweed extract we've been talking about it seems like it's doing way more than just helping those seeds germinate.

Lilly 6:27

Oh yeah.

Osmosis and Transplant Tolerance

Jad 6:28

It's affecting how water moves and even how gases are exchanged inside the plant, and it brings us back to that idea of osmosis working on all these different levels.

Lilly 6:39

Right.

Jad 6:39

From the cells all the way up to the whole plant.

Lilly 6:41

It's fascinating. You know, what really strikes me about all this research is how connected everything is. Yeah.

Roger 6:46

It's fascinating.

Lilly 6:46

You know, what really strikes me about all this research is how connected everything is. We've seen how root traits like SRL are totally linked to a tree species ecological strategy, and how those strategies are shaped by their soil environment. It's like this chain reaction, where one thing impacts another and it all comes back to how well that tree can get to and use water Precisely. And then we add in the seaweed extract, which can even affect gene expression and how water moves within the plant Right. It really shows just how complex these interactions are.

Jad 7:15

Okay, before we really dig into the seaweed extract, I want to go back to that study by Giuliani and their team for a second.

Lilly 7:20

Okay.

Jad 7:21

I'm still thinking about that finding with the Areridopsis roots.

Lilly 7:24

Yeah.

Jad 7:25

Where they actually had trouble in that compacted, heterogeneous soil Right. It really makes you question that idea that more macropores always means better root growth.

Lilly 7:35

Absolutely. It shows that context matters.

Jad 7:37

Yeah.

Lilly 7:37

What works for one species might not work for another, and even within the same species, the ideal soil structure can be different depending on things like root size and how compacted the soil is.

Jad 7:48

Okay, so as arborists, we need to be paying attention to the specific needs of each tree species, right, and what the soil they're growing in is like.

Lilly 7:57

Exactly, it's about understanding those details.

Jad 7:59

Yeah.

Lilly 8:00

If you're working with a species known for having an aggressive root system, like our hawthorn example, you probably don't need to worry as much about soil contraction. Those roots will likely find a way, but for a species with more delicate roots like beech, creating a soil environment with good aeration is super important, especially in compacted soils.

Jad 8:20

That makes sense. So things like soil amendments, mulching and aeration techniques become even more important when we're dealing with those sensitive species.

Lilly 8:28

Absolutely. It's all about using our knowledge to create the best possible underground environment for those trees.

Jad 8:35

I totally agree. Okay, so let's switch gears a bit and talk about this hysteria. Seaweed extract.

Lilly 8:41

All right.

Jad 8:42

It seems like it's doing more than just boosting germination. Common's team found some evidence that it might even be influencing transpiration rates.

Lilly 8:49

Right, remember those compounds in the seaweed extract we talked about earlier, the ones acting as osmotic agents. Well, it seems like they can actually change the water potential within the plant cells, and that impacts how water moves through the whole tree.

Jad 9:03

It's like fine-tuning the tree's internal plumbing.

Lilly 9:06

That's a great way to put it. And this fine-tuning can affect other processes too, like transpiration, nutrient uptake and even photosynthesis.

Jad 9:14

Which leads us to another interesting finding from the study. The seaweed extracts seem to increase what they call stomatal limitations to photosynthesis in Fagus sylvatica. So basically it looked like it made it a bit harder for the beech leaves to take in carbon dioxide.

Lilly 9:30

Uh-huh, which they need for photosynthesis.

Jad 9:32

Yeah, it seems counterintuitive.

Lilly 9:33

Right.

Jad 9:34

You'd think something that helps with germination and water management would also help with photosynthesis.

Lilly 9:39

You would think so.

Jad 9:39

But, as we've been saying, plants are complex.

Lilly 9:41

They are.

Jad 9:42

And even a single change can trigger a whole bunch of responses. And some of those might seem contradictory at first.

Lilly 9:48

Yeah, it's not always clear cut.

Jad 9:49

So it's not really a good thing or a bad thing.

Lilly 9:51

Right, it's just a.

Jad 9:52

Thing.

Lilly 9:52

Exactly, and it shows how much we still don't know about how these extracts interact with different tree species Right On a physiological level.

Jad 10:00

Yeah, what might be good for one species might have unexpected effects on another.

Lilly 10:05

Absolutely.

Jad 10:06

So, as arborists, how do we make sense of all this?

Lilly 10:08

Yeah.

Jad 10:09

We know seaweed extract can affect water movement and how the stomata behave. Right, how can we use that knowledge in the field?

Lilly 10:16

Well, one area where this could be really important is transplant shock. You know newly transplanted trees are super vulnerable to water stress, yeah, and anything we can do to help them manage their water balance during that critical time Right Can really affect whether they survive.

Jad 10:32

So could applying seaweed extract when we transplant trees actually help reduce that transplant shock.

Lilly 10:38

That's a great question.

Jad 10:39

Yeah.

Lilly 10:39

And it's definitely something we need to research more.

Jad 10:41

Yeah.

Lilly 10:42

Given how the extract might help with osmotic adjustment, it's possible that it could help trees acclimate to their new environment more effectively.

Jad 10:51

That's a really interesting thought.

Lilly 10:53

Yeah.

Jad 10:53

Imagine if we could use seaweed extract to make transplants more successful.

Lilly 10:57

It would be a game changer.

Jad 10:58

But of course, like you said, we need more research. We do To be sure it works and figure out the best way to apply it.

Lilly 11:03

Absolutely, but these are the kind of questions we need to be asking.

Jad 11:07

Yeah.

Lilly 11:07

And this research gives us a lot of valuable information to guide those questions.

Jad 11:11

Right. It all comes back to understanding those basic principles of plant biology.

Lilly 11:15

Exactly.

Jad 11:16

And that's what helps us develop better and more effective ways to take care of trees.

Lilly 11:20

Couldn't agree more.

Jad 11:22

We've been looking at how osmosis works in all these different situations, from seed germination to root development, to how trees manage water. But how does all this connect to the challenges that arborists are dealing with in the real world?

Lilly 11:37

Yeah.

Climate Change and Arborist Challenges

Jad 11:37

Especially with climate change being such a big issue.

Lilly 11:40

That's the big question, isn't it?

Jad 11:41

Yeah.

Lilly 11:42

As the climate changes, trees and cities are facing more and more stress.

Jad 11:46

Right.

Lilly 11:46

From hotter temperatures, more droughts and extreme weather.

Jad 11:49

Yeah.

Lilly 11:50

All these things can mess with a tree's osmotic balance and make it harder for them to do well.

Jad 11:55

So as arborists, we can't just plant trees anymore.

Lilly 11:58

Right.

Jad 11:58

We need to be planting trees that can handle these tougher conditions.

Lilly 12:02

Absolutely Trees that can survive drought and heat stress and all the other pressures that come with a changing climate.

Jad 12:09

Exactly. We got to choose the right trees for the right spots, prep the soil properly and give them the care they need to stay resilient.

Lilly 12:17

It all starts with understanding what trees need and how they interact with their environment, especially when it comes to water.

Jad 12:24

And that's where a good understanding of osmosis is so important.

Lilly 12:27

Absolutely.

Jad 12:27

It gives us the knowledge to make smart choices about everything From what species to plant, to how to plant them, to how to water them.

Lilly 12:34

We can use that knowledge to help trees thrive.

Jad 12:37

Yeah, even when things get tough. Okay, as we wrap up this deep dive, I want to leave our listeners with one final thought-provoking idea.

Lilly 12:44

Okay.

Jad 12:45

We've seen how crucial osmosis is for trees to survive.

Lilly 12:48

It's essential.

Jad 12:49

Now imagine if we could use that understanding to create brand new ways to take care of trees.

Lilly 12:55

That's a great point.

Jad 12:56

What if we could figure out how to manipulate those osmotic processes, even in small ways? Right, could we make trees more drought tolerant? It's possible. Could we help them fight off diseases better?

Lilly 13:07

Yeah.

Jad 13:07

Could we find new ways to help them bounce back from stress?

Lilly 13:09

There are so many possibilities.

Jad 13:11

So to all the arborists listening.

Lilly 13:13

Keep learning.

Jad 13:14

Keep asking questions, Keep pushing so to all the arborists listening, keep learning, keep asking questions keep pushing the limits of what you know. Yeah, the future of our urban trees depends on it.

Lilly 13:19

I agree. Well said, I think that's a perfect way to wrap things up.

Jad 13:23

Yeah, thanks so much for joining me on this deep dive into the world of osmosis and tree care.

Lilly 13:27

It's been a pleasure.

Jad 13:28

To all our listeners out there, keep those dendrites firing.

Lilly 13:31

Yeah.

Roger 13:39

There's always more to learn in the amazing world of trees. Until next time, happy arboring. Thank you for joining us on today's exploration into the science of tree and plant growth. We've uncovered the short-term benefits of Ascophyllum nodosum extract on trees, delved into how complex soil structures can shape root development and revisited the fundamentals of tree biology. We hope these insights inspire you to look at nature's details with fresh eyes. Until next time, keep nurturing the green around you.