Roger: 0:02

Talking Trees with Lily and Jad. In today's episode, we'll be looking at two key resources that highlight the critical role veteran trees play in supporting biodiversity. Both delve into the diverse array of species—fungi, mosses, lichens and insects—that depend on ancient trees for their survival and describe specific tree-related micro-habitats that impact biodiversity. Let's dive in and explore how these unique habitats contribute to the preservation of biodiversity.

Jad: 0:37

Welcome back to the Deep Dive, ready to explore something pretty amazing, always Okay. So today we're going super small scale.

Lilly: 0:45

Okay.

Jad: 0:45

Like think about a forest. You see the big picture right, trees leaves the whole scene Right, but we're zooming in way in.

Lilly: 0:59

Yeah, to the world of dendro-microhabitants. Yeah, these are like the hidden ecosystems within trees themselves, not just you know the branches and bark, but cavities cracks. Even the way other organisms like fungi create these mini environments.

Jad: 1:09

This is crucial for anyone who you know works with forests professionally Forestry conservation, you name it. You're the perfect person to break this down for us because, like I'm already fascinated. But how does understanding these tiny habitats help us understand the big picture of a forest?

Lilly: 1:25

when you get dendro microhabitats you really get forest ecology. Each one is unique, right so size, shape where it is on the tree, how much decay.

Jad: 1:33

There is even sunlight, all of that wow, so many factors yeah, it determines what can live there so it's like each tree is a whole world with different neighborhoods, and the more diverse those neighborhoods are, the healthier the whole forest is.

Lilly: 1:46

Exactly. More microhabitats mean more different kinds of species can exist. That's biodiversity in action.

Jad: 1:53

Okay, I'm seeing it now. So to really protect forests, we got to understand these little worlds. Our research turned up some awesome examples of dendro-microhabitats Cavities.

Lilly: 2:06

Like ecological gold mines, and there are different kinds Rot holes. Those are filled with decaying wood.

Jad: 2:11

Okay, so not just empty space, but a whole ecosystem in there.

Lilly: 2:14

Absolutely Full of life, and in long-lived trees like oak trees, these rot holes can last for centuries.

Jad: 2:21

Centuries Wow.

Lilly: 2:22

Then there are woodpecker cavities. You know where they nest.

Jad: 2:26

Yeah, yeah, yeah.

Lilly: 2:26

Those become homes for other species too, once the woodpeckers are done.

Jad: 2:29

So it's like a chain reaction of habitat creation it is. Our sources said that like 95% of woodpecker cavities in oak trees are connected to wood decay fungi. So it's like the fungi soften up the wood, then the woodpeckers come in. So it's like the fungi soften up the wood, then the woodpeckers come in.

Lilly: 2:44

That's exactly it. It's this amazing partnership. The fungi get to spread, the woodpeckers get a home. It's a win-win.

Jad: 2:51

Amazing, but cavities aren't the only thing, right? What about injuries to trees or places where wood is exposed?

Lilly: 2:57

Yeah, damage can actually create great habitats. Think about fire scars.

Jad: 3:02

Oh, right, right, that charred wood, the exposed surfaces it creates a home for species like those disturbed areas. So even fire, which we think of as destructive, can help create diversity, exactly.

Lilly: 3:13

And then smaller stuff like bark pockets, where the barks come loose, that's shelter for insects, spiders, all kinds of little guys.

Jad: 3:20

Makes you think about like looking closer to everything. You never know what you'll find.

Lilly: 3:23

Oh, absolutely. And speaking of finding things, get this. Studies have shown that, on average, one kilogram of soil from a tree cavity has about 2,500 arthropods in it.

Jad: 3:34

Wait, 2,500? That's a whole city in a handful of dirt.

Lilly: 3:37

It really shows how much life is happening that we don't even see. And all those tiny creatures are important Decomposers, nutrient cyclers. They keep the forest running.

Jad: 3:47

Okay, I'm seeing it now. The forest for the microhabitats. So we've done cavities, we've done injuries. What about the penthouse suite? The stuff growing on trees, epiphytes.

Lilly: 3:57

Ooh, yeah, the treetop apartments, those are the mosses, lichens, sometimes ferns.

Jad: 4:04

I always thought of them as just like decoration, but they're creating their own little ecosystems up there.

Lilly: 4:09

They are, and they're important. Like mosses and lichens, absorb moisture from the air. That helps regulate humidity, creates microclimates for other things.

Jad: 4:16

They're like the forest's natural air conditioners, keeping things cool and comfortable.

Lilly: 4:20

Exactly.

Jad: 4:25

And mistletoe, the holiday favorite. But it's also like essential winter food for birds. But who are the tenants in these treetop apartments? What kind of organisms are we talking about?

Lilly: 4:31

Oh, so many Insects, arachnids, fungi, even amphibians and small mammals. It's a diverse crowd.

Jad: 4:37

I bet. Okay, let's get specific. Give me some examples. Who are the superstars of the dendro micro habitat world?

Lilly: 4:44

Well, one really cool example is the osmoderma aromida, or the hermit beetle. It's pretty rare and it needs the decaying wood of old trees to survive.

Jad: 4:54

So if we lose those old trees, we lose this beetle and probably a lot more.

Lilly: 4:58

Exactly, it's all connected. Another good one is the lucanus cervus, the stag beetle. Its larvae live in decaying stumps, so important to leave that dead wood around Right.

Jad: 5:08

It might look messy to us, but it's home to all sorts of life.

Lilly: 5:11

Absolutely. And then we can't forget bats. Lots of bat species use tree cavities to roost and hibernate.

Jad: 5:18

Makes sense Safe and cozy. What about, like mammals that don't fly, do they use these microhabitats too?

Lilly: 5:24

Yeah for sure, red squirrels, pine martens, some rodents they'll use cavities for shelter raising their young.

Jad: 5:29

It's amazing how much is going on in those trees, but with so many different organisms, I got to ask what does all that life do to the tree itself?

Lilly: 5:39

That's a great question. It's a complex relationship, right? Sometimes it's good, sometimes not so much. Well, take bats, for instance. Their guano might seem gross, but it's actually a really good fertilizer. So the bats get a home, the tree gets nutrients.

Jad: 5:54

A built-in composting system.

Lilly: 5:55

Yeah.

Jad: 5:56

Love it, but it's not always a happy partnership, right.

Lilly: 5:59

Right. Some organisms can bring diseases or parasites. Too much burrowing can weaken the tree. It's a balance.

Jad: 6:06

Like everything in nature. I guess we need to understand those interactions to manage forests effectively.

Lilly: 6:12

Exactly. It's not about getting rid of any one thing, but about managing the whole system so everything can thrive, and that's where we come in right. As professionals, we need to understand these little details to do our jobs well.

Jad: 6:24

Exactly Speaking of doing their job. What about birds? They're all over the forest, but I don't usually think about where, in the trees, they actually live.

Lilly: 6:32

It's pretty cool when you start to think about it, especially with those old trees, the veteran trees. Right, those are like bird hotspots, all those microhabitats they have. It's not just a place to hang out, it's nesting sites, tons of food.

Jad: 6:45

So it's more than just like singing a pretty song.

Lilly: 6:47

Oh yeah, of food. So it's more than just like singing a pretty song. Oh yeah, think about all the insects in the decaying wood, the bark that's a buffet for birds, plus the cavities for nests raising their young.

Jad: 6:58

We talked about woodpecker cavities, but other birds use those too, right All the time Woodpeckers are like the construction crew.

Lilly: 7:04

Then you get owls, kestrels, even little birds like marsh tits and tree creepers will move right in. Maybe do a little redecorating.

Jad: 7:12

Like finding a fixer-upper, but some birds are probably pickier than others, right?

Lilly: 7:15

Oh yeah, for sure, like nuthatches they're known for, like really customizing those cavity entrances Got to be the right fit.

Jad: 7:22

Wow. So they're not just finding a home, they're shaping it too.

Lilly: 7:25

And that affects what other insects can live in there. So they're changing the whole microhabitat.

Jad: 7:29

Like a domino effect.

Lilly: 7:30

Yeah.

Jad: 7:31

But what about food? Do birds find that in the microhabitats too? Are they like pecking into the wood itself?

Lilly: 7:37

Some do the woodpeckers. Obviously they're pros at that, but most birds they get their food from the bark or little cracks and crevices snagging insects, spiders, that kind of thing.

Jad: 7:48

So it's a full-service dendro-microhabitat experience Shelter, food, the works. What about mammals, though? Not just the bats and squirrels, but others too?

Lilly: 7:57

Oh yeah, lots of mammals that we think of as like ground dwellers use those treetop spots, especially cavities.

Jad: 8:04

Oh, interesting.

Lilly: 8:05

Like foxes, pine martins, even some rodents, they'll use them for shelter, especially in bad weather, or for their babies.

Jad: 8:12

A whole hidden world up there. But I got to ask with all these different animals coming and going, does that hurt the trees?

Lilly: 8:19

It's complicated. Sometimes it's good for the tree, sometimes not, Like with the bats right their guano. Yeah, it might seem like a bad thing, but it's actually a fantastic fertilizer. So the bats get a home, the tree gets nutrients, everyone's happy.

Jad: 8:32

It's amazing how that works out sometimes.

Lilly: 8:34

Yeah.

Jad: 8:35

But I'm guessing it's not always that perfect.

Lilly: 8:37

True.

Jad: 8:37

So it's a trade-off.

Lilly: 8:38

True.

Jad: 8:38

We need to understand both sides to keep the forest healthy.

Lilly: 8:41

Yeah, it's about managing the whole ecosystem, not just focusing on one part Makes sense. Yeah, focusing on one part.

Jad: 8:46

Makes sense. Yeah, our research also mentioned something called mycorrhizal fungi. I've heard the term, but I'm not totally sure what they are.

Lilly: 8:53

Oh, they're essential. They're these fungi that have a partnership with tree roots. They're practically part of the root system.

Jad: 9:00

Oh, interesting.

Lilly: 9:02

Yeah, they're like little helpers. They have these threads called hyphae that spread through the soil and they can get to nutrients that the tree's roots can't reach on their own.

Jad: 9:10

So they're like extending the tree's reach.

Lilly: 9:12

Exactly, and in return the tree gives the fungi sugars from photosynthesis. It's a win-win.

Jad: 9:20

Do all trees have this kind of partnership with fungi?

Lilly: 9:22

Pretty much all of them, yeah, and what's cool is that certain fungi only pair up with certain trees. It's very specific.

Jad: 9:28

Wow, it really shows how interconnected everything is. If the fungi aren pair up with certain trees, it's very specific. Wow, it really shows how interconnected everything is. If the fungi aren't healthy, the trees probably aren't either.

Lilly: 9:34

That's exactly right. The health of the whole forest depends on these relationships working, and when we understand them, we can take better care of the forest.

Jad: 9:43

Speaking of interconnectedness, let's talk about epiphytes again, those air plants that grow on trees. You know, we touched on them earlier, but yeah, the mosses lichens some ferns. Right right, I've always just seen them as like adding a little bit of green, but they're actually important for the ecosystem.

Lilly: 9:58

Oh, for sure. They increase the tree's surface area so that helps trap moisture and nutrients from the air, and they create microhabitats for other things too.

Jad: 10:07

So they're like tiny ecosystem engineers.

Lilly: 10:09

Exactly, they add another layer of complexity to the whole dendro-microhabitat thing.

Jad: 10:15

But with so much going on, are there any downsides? Could these microhabitats actually hurt the trees?

Lilly: 10:26

Most of the organisms in these microhabitats are either good for the tree or they don't really do anything either way, but there are some downsides, yeah, yeah.

Jad: 10:31

Like what.

Lilly: 10:31

Well, some fungi and insects can cause decay or disease, especially if the tree is already stressed or weak.

Jad: 10:39

So it's like anything too much of a good thing can be a bad thing.

Lilly: 10:42

That's a good way to put it. We need to understand how trees and their microhabitat residents interact. That's how we keep the forest healthy.

Jad: 10:50

Are there like visual cues that can tell us if a tree is healthy and has a good relationship with its dendro-microhabitat residents?

Lilly: 10:57

There are some things you can look for, Like certain mushrooms around the base of a tree can mean there's a healthy network of mycorrhizal fungi. And the tree itself. How vigorous it looks, the color of its leaves, how fast it's growing, those are all clues too.

Jad: 11:11

So it's about paying attention to the little details, reading the language of the forest.

Lilly: 11:15

Okay, let's talk about saproxilic beetles. They're all about decomposition, right.

Jad: 11:19

Oh yeah, they're the masters of decay. They need dead and decaying wood to survive at least for part of their lives, and there are tons of different kinds, all adapted to different types of dead wood.

Lilly: 11:31

So they're like the forest's recycling crew, breaking down the dead stuff so the nutrients can be used again. That's it, along with the fungi. They're super important for keeping the forest healthy and they have different preferences right. Some like wood that's just starting to decay, others like it really rotten. That's why it's so important to have different kinds of dead wood in the forest.

Jad: 11:51

Like a buffet for the beetles. But what happens if we take all the dead wood away, like they do in some managed forests?

Lilly: 11:58

That's really bad for the beetles and it hurts the whole forest because it messes up the nutrient cycle. Dead wood isn't just trash, it's a vital part of the forest.

Jad: 12:07

I'm seeing a pattern here. What we might think of as waste is actually really important for the ecosystem.

Lilly: 12:13

Exactly so. We need to manage forests in a way that recognizes that.

Jad: 12:18

With so many different types of saproxilic beetles, are there any that are like especially interesting or important?

Lilly: 12:25

Definitely the hermit beetle we talked about earlier. That's a big one. It's really picky about what kind of dead wood it needs and it only lives in healthy, old-growth forests. So if you see that beetle you know the forest is doing well.

Jad: 12:39

That's really cool. Are there other beetles like that with super specific needs?

Lilly: 12:42

Oh yeah, tons like the Rosalia alpina or the alpine longhorn beetle. It's gorgeous blue-gray color long antenna, but it can only live in dead beechwood and it has to be in a sunny spot.

Jad: 12:56

So it's not just about having deadwood, it's about the right kind of deadwood in the right place. That must make things tricky for forest managers.

Lilly: 13:04

It does. It just shows how complex these microhabitats are and how important it is to understand them.

Jad: 13:09

Let's talk about cavities again for a minute. They're really important for shelter, right.

Lilly: 13:13

Absolutely. Tree cavities protect animals from predators, bad weather, all sorts of things, and they're perfect for raising young. Lots of animals use them bats, birds, even some mammals that usually live on the ground.

Jad: 13:25

So they're like little safe havens in the forest. Ah, but I bet there's a lot of competition for those prime spots.

Lilly: 13:30

You bet, Different species like different sizes and shapes of cavities, and some like them high up, some like them lower down. So there's definitely a struggle for the best real estate.

Jad: 13:39

It's like a game of musical chairs, but with really high stakes. Are there other things besides competition that affect how many cavities there are?

Lilly: 13:53

Yeah, the age of the forest is a big one. Old forests with lots of different kinds of trees have way more cavities than young forests, where all the trees are about the same age.

Jad: 13:58

So old growth forests are super valuable for biodiversity, not just because they look cool.

Lilly: 14:04

Exactly, and it's not just the age of the trees, it's the deadwood too. As trees get older and start to decay, they're more likely to develop cavities. It's part of the natural cycle of the forest.

Jad: 14:14

That's pretty amazing One generation of trees helping create homes for the next. Okay, let's switch gears a bit and talk about how dendro-microhabitats help with nutrient cycling in the forest.

Lilly: 14:25

That's a big one. We often focus on the things we can see the trees, the animals but there's a whole lot going on underground and inside the trees themselves. That's what keeps the forest alive.

Jad: 14:36

So we're talking about decomposition, breaking down all that dead stuff into nutrients that plants can use.

Lilly: 14:41

Exactly, and dendro-microhabitats are a big part of that. Like when dead wood decomposes in a tree cavity, it releases nutrients that help trees and other plants grow it's like a built-in composting system, but is that the only way?

Jad: 14:53

dendro micro habitats help with nutrient cycling?

Lilly: 14:56

nope, animal droppings and other organic matter accumulate in cavities, and that adds nutrients too. Plus there are all those fungi and bacteria in there breaking down complex stuff into simpler stuff that plants can absorb.

Jad: 15:09

Wow, so much is going on in those little worlds, but how do we make sure this nutrient cycling is working properly?

Lilly: 15:16

Well, diversity is key, like we talked about before. The more different kinds of trees there are, the more different kinds of dendro-microhabitats there are, and that means more pathways for nutrients to move through the ecosystem.

Jad: 15:29

So it's like having a backup system If one pathway gets blocked, there are others that can take over.

Lilly: 15:34

Exactly, and there are other things we can do too, like minimizing soil disturbance during forestry operations. That protects the fungi and bacteria that are doing all the hard work of decomposition.

Jad: 15:44

Right. We don't want to mess up their homes, and leaving deadwood in the forest instead of taking it all away is good too, right.

Lilly: 15:49

Definitely. Deadwood is like a nutrient bank for the forest.

Jad: 15:52

Okay, so we've talked about the ecological benefits of dendro-microhabitants. Are there any ways they benefit humans directly?

Lilly: 16:01

Well, the ecological benefits are the most important thing, of course, but those benefits trickle down to us too.

Jad: 16:07

Okay, I like where this is going.

Lilly: 16:09

For example, healthy forests with lots of dendro-microhabitats are better at resisting pests and diseases, and healthy forests also help regulate the water cycle, clean the air and fight climate change. Those are all things that are good for human health.

Jad: 16:24

It's amazing how something so small like a little microhabitat in a tree can have such a big impact on everything.

Lilly: 16:32

It really shows that we're all part of nature and everything we do affects everything else.

Jad: 16:34

Okay, I'm definitely feeling inspired to go out and explore some dendro microhabitats, but before we wrap up, what advice would you give to someone who wants to learn more?

Lilly: 16:42

There are some great resources out there. One book I really like is the Field Guide to Tree-Related Microhabitats. It's got tons of pictures and descriptions of different microhabitats.

Jad: 16:54

Sounds like a good place to start. What else would you recommend?

Lilly: 16:57

The Ancient Tree Forum website is awesome. They have a lot of information on veteran trees, those really old ones.

Jad: 17:03

And I bet there are some good websites too, oh yeah, woodlandscouk is great.

Lilly: 17:12

They have a whole section on dendro microhabitats and if you want to get really into it, there are tons of research articles on Google Scholar.

Jad: 17:15

So many ways to learn. Well, I think that about covers our deep dive into dendro microhabitats. What a journey.

Lilly: 17:22

It's been fun.

Jad: 17:23

And a big thanks to our listeners for coming along with us. We hope you've learned something new and are feeling as excited about these hidden worlds as we are. How do we actually use this dendro-microhabitat knowledge to manage forests better?

Lilly: 17:35

It's a big shift, yeah, for a lot of forestry professionals. We have to move away from just thinking about timber and start thinking about, like, the whole web of life in the forest.

Jad: 17:45

Seeing the forest for the microhabitats basically they the whole web of life in the forest.

Lilly: 17:48

Seeing the forest for the microhabitats basically they're tiny but they matter for the whole system Exactly, and one big thing is we got to keep those veteran trees, the old ones and the bedwood.

Jad: 17:56

So no more cleaning up every little branch and fallen log.

Lilly: 17:59

We need to leave enough for the ecosystem to stay healthy.

Jad: 18:03

Working with nature, not against it. What about forests that have already been managed a lot, though? Can we bring back those microhabitats?

Lilly: 18:10

We can. It takes time but we can help. Sometimes we actually create artificial dendro-microhabitats, like drilling holes in trees to mimic woodpecker cavities or piling up logs to mimic deadwood.

Jad: 18:23

So we can give nature a little boost, but it's not as easy as just putting up a birdhouse.

Lilly: 18:28

Right. You have to know what you're doing, what species you're trying to help, what their needs are. But if you do it right, it can really help bring back biodiversity.

Jad: 18:37

It's like designing a forest. What about new forests, though, the ones we're just planting?

Lilly: 18:42

Gotta think long term there, planting different kinds of trees, especially the ones that develop cavities and stuff as they age. That's how you build a healthy forest for the future.

Jad: 18:51

Planting for the microhabitats. Well, that wraps up our deep dive into the incredible world of dendro microhabitats, and to our listeners, we hope you've enjoyed this journey into the hidden heart of the forest. Next time you're in the woods, take a closer look. You might be surprised by what you find. Until next time, happy exploring.

Roger: 19:14

That brings us to the end of today's episode, where we explored the vital connection between veteran trees and biodiversity. From the unique species that call these ancient trees home to the microhabitats that sustain them, it's clear how crucial these ecosystems are to preserving our natural world. Thank you for joining us and, as always, we appreciate your continued support. We'll be back with more insights into the world of arboriculture and tree care. Until next time, keep nurturing the trees and ecosystems around you.