♪ >> Welcome to Canada Files .

I'm Valerie Pringle.

My guest today is Suzanne Simard, who is a professor of forest ecology at the University of British Columbia.

She has spent her life observing forests.

She has published 200 groundbreaking articles showing that trees exchange signals and resources through a hidden underground communication system.

Her memoir, Finding the Mother Tree: Discovering the wisdom of the forest, documents her revolutionary journey.

>> Hello, Suzanne.

>> Suzanne: Hello.

>> Are you revolutionary?

Are your ideas about trees and forests revolutionary?

>> I never thought that they were but they are in so many ways.

I didn't think they were because I grew up understanding forests as these really connected relational places.

Then I studied it and now I'm talking about it.

People are going, "Wow, I never thought of forests that way!"

I always did.

>> Explain your premise.

When you say it in a nutshell-- are trees sentient ?

What's going on underground and between trees?

What's happening in forests?

>> Most of us think of trees as just these individual trees that are living in a forest and trying to get what they need.

Of course they do, but what I've found out and realized in trying to express is that they are very social creatures.

They actually live in community.

They live in social networks.

They're connected to one another.

They have deep relationships, sophisticated relationships.

They're very responsive and communicative with each other.

Once we start seeing trees as very dependant on their society, their community, we start to understand them as different .

They're more fulsome, holm or holistic then we used to think that they were.

That brings on all kinds of thoughts about how deep these trees are.

What is it about their-- you said sentient, that conjures up that they have purpose, agency and meaning in their lives.

The work that I do, shows that they do.

They have the ability to determine their own future in so many ways.

>> You've spent your life really observing and listening to forests and trees.

You grew up in the rainforests of British Columbia.

With an extended family, grandparents loggers, quite a cast of characters actually.

Tell me about your family.

>> My family on my father's side-- my great grandfather, grandfather, my dad's family, all those generations were horse loggers.

That just meant that they had horses they would actually take across the lake on these wharves and tugboats they made by hand.

All these boats and tools, flumes that they built.

My grandfather even built a water wheel.

House boats they lived on while they were logging.

All of that was done by hand and I was just born into that.

>> Valerie: But in total comfort in the forest?

>> Yeah, it was where we lived.

There were no other way to know things.

>> There are a couple of origin stories you tell about your curiosity.

And the beginnings of the great why and what's going on.

One is about the family dog, Jigs, in an outhouse.

>> Yeah.

Jigs was just part of our family.

Jigs was a beagle dog and Uncle Wilfred had this big boat he'd made.

He would be on the lake all the time with Jigs at the bow of the boat.

Jigs would be up there pointing the way or, at least his nose was pointing the way.

One day, us little kids-- I was 6 years old at the time, we wake up in the morning and we hear this howling.

We all know it's Jigs.

It's from within the forest where the outhouse is.

We all go running out because we realize Jigs has fallen in the outhouse.

My Uncle Wilfred comes running up the shore with his shovel, my grandpa with his pick axe and my dad, all the little kids are running up.

We open up the outhouse door and look down.

There's Jigs paddling around in the soup way down there.

And, of course, we have to get Jigs out.

The men start to dig and they're going-- I was learning so much.

I mean I was feeling really bad for Jigs but I was completely mesmerized by what they were uncovering.

As they went through the soil, beside the outhouse to get him out, it was like all the colours, right?

There was this big thick moss layer.

Then there was this white layer, then this red layer, and then this yellow layer.

All the roots whether white and brown roots.

There were mushrooms coming out at the top.

I exclaimed, oh my God!

What is this masterpiece that's the soil?

I couldn't believe it.

It took quite a while to take the stones out.

Finally my dad pulled up Jig's paws and pulled them out.

We ran down and threw him in the lake... >> No kidding!

That was the moment for you.

>> That was a big moment for me.

>> Another moment that you describe very well, you're 20 years old working for a logging company.

That's one of these clear-cutting logging companies.

They're trying to plant more seedlings to replace everything that they've taken away.

You're documenting all these dead plants.

And you say, "Those yellow seedlings sent me on a long journey of a lifetime" It was the great why .

And how did you answer it?

Why weren't those trees surviving?

Why weren't the plants taking root?

>> I got this job.

I was one of the first girls to get a summer job for a forest company.

Which I thought I really accomplished something.

I loved it because I loved the forest.

My job was to follow these growing clear-cuts and plant the clear-cuts with trees.

At least to get planters to plant those clear-cuts.

I was going back to them and seeing how they were doing.

I would go back and the little D ouglas Firs would be yellow and not growing.

Some would grow for sure, but a lot of them didn't.

I would pull them out and I'd look at their roots and go well, there's nothing going on here.

There's like a black tube going into the soil.

I would pull out ones that were growing naturally.

The ones that had come from the seed from the trees and then landed and germinated.

The roots would be like everywhere.

What's the difference?

Obviously, there was a huge difference.

The naturally-regenerated trees were just finding their way to the nutrients in the water.

Whereas the planted ones that were in these plugs were kind of entombed in the plug.

So that got me thinking about roots, then I was looking at the roots.

They were covered in these colourful little fungal threads.

I started learning about this fungus called mycorrhiza .

It helps seedlings grow.

I could see this big difference between these.

One had mycorrhizas and these complex root systems and the other one had neither of those.

That's where I got started in thinking about roots.

I came from being a kid that loved dirt and soil... >>...And ate it!

And was mesmerized by it.

To I would like to study why these trees are not doing well in a soil that should be very productive and very supportive of their growth.

>> That sent you off on a journey you're still on decades and decades.

>> I grew up in an old-growth forest and I've watched over my lifetime.

I was born in 1960.

Imagine Canada and British Columbia where I lived, were just covered with old forests.

Then I became part of this industry that was cutting them down.

The cutting was going on and on and accelerating.

Soon the vast landscape of old forest was turning to vast landscape of clear-cuts.

And I just started to-- it became more and more urgent to me to contribute to slowing this down and figuring out what we were doing.

Are we replacing these beautiful old-growth forests with these sickly plantations.

And shouldn't we think about this more and solve some of these problems.

That became my life's work.

>> When you describe your work in the forest.

And endless experiments and time in the forest.

The danger !

I'm thinking, on so many levels of you working with Roundup.

Which was used so extensively, so toxic... >>...still is.

>> And neutron probes , radioactive carbon.

which you're dealing with, trying to protect yourself from.

Let alone the grizzly bears that were chasing you up trees.

>> When you think of experiments and scientists, you think of them in labs with test tubes, some electrode, or bacteria in a Petri dish.

When you are doing research in forests it's a completely different thing.

Because you're living that experiment.

You're surviving in your experiment.

Because there are bears, cougars, wolves around.

Then the instruments we use could be really dangerous.

Even though at the time... I'll get by.

I just got to do it, and I'll get by.

I think the other thing to think about too is that the trees we are studying are huge!

Especially in the rain forests, you could have diameters that are meters wide and 50 meters tall!

They live a long, long time.

When you're doing experiments, these are long experiments.

Longer than your lifetime.

So when you set something up, you know it's big and it's long.

You need lots of people involved.

It's actually in that way just so much fun.

It has to involve lots of students and colleagues.

It's teamwork.

Then you're working in these big areas with big animals around, you know like bears.

>> You were lucky you weren't killed by the bears.

>> Yeah, honestly I was!

Especially in the 1980s, when I worked alone in grizzly country a lot.

They just put us out there, or at least me.

>> You spent quite while in a tree at one point thinking you may never come down.

Waiting for the grizzly to leave.

>> Yeah, this was in a tributary to the Fraser River.

It was near where I was working.

My friend, Gina, and I had gone hiking.

And we knew there were grizzlies up in the valley.

This was their territory even though I really wanted to spend my 22nd birthday up there.

She was in front of me and all of a sudden she stopped.

I'm like, "What's going?"

She goes, "Grizzly!"

Only about 5 feet away from her was this huge mama grizzly with two cubs right beside her She's looking at us and Gina's looking at her.

She goes, "I'm going to go up that tree."

I'm going, "Oh, I'll go up this tree over here."

The mama takes her cubs off to another tree.

We're all climbing our trees while the cubs are climbing.

She can't climb because she's too big.

It took quite a while.

We were up there about an hour.

Mama Grizzly finally kind of got bored and, or figured we were fine up there and got her cubs down out of the tree.

We could hear them leaving.

Finally just as it's getting dark, we get down from our trees and we get the heck out there as fast as possible.

>> Tell me about the eureka moment when you heard trees talking to each other.

Birch to fir, after all the experiments you were doing.

You've found evidence that something was going on between.

>> I had this idea even when I was doing my master's degree ... what we're talking about is the experiment that I did during my doctoral studies.

I thought in my master's experiment, where I was looking at how trees are competing for water and nutrients.

I thought what if they shared them.

I would in my experiment labelled the Douglas Fir with a radioactive tagged carbon dioxide.

I would put a bag over the tree, injected the CO2 with C14 on it.

Then the birch I would put a bag on it, injected Carbon 13 CO2, a stable isotope.

I waited and then went with the Geiger counter and tested to see whether or not I was able to label these trees properly.

There were the donor trees that I had labelled.

I could hear the radioactivity with the Geiger counter going tshtsh.

I went over to the fir because if it had received any of this radioactivity I would be able to hear it.

I went up to it with the Geiger counter and I could hear a little crackle.

That was when I knew that something had happened.

Something had moved from this tree to this tree.

Of course, that was just kind of the beginning but that was an incredible moment.

Getting the data back when we had to analyze it carefully in a lab in Victoria which is a whole other story.

I finally got the data back and I could see that this carbon 14 and carbon 13 were moving back and forth between the birch and the fir.

And that the birch was sending to more carbon to fir.

Than fir was sending back to it.

That was an incredible moment!

Because I knew they were communicating back and forth between each other.

>> Just ...your head must have blown off.

>> Pretty much!

>> You wrote an article that was on the cover of Nature Magazine.

That was 1997.

Another real breakthrough moment for you.

The description of what, the Wood Wide Web .

>> Yup.

That was the paper that resulted from that experiment.

It was so mind-blowing that these trees out in the forest were sharing, trading carbon back and forth between them.

Until that moment we kind of knew the mycorrhizal fungi could link trees link together.

That was kind of established.

I say kind of because it was all very new at that time.

There had been an experiment done before in the lab showing that trees could connect.

I was the first one to show that this carbon was moving back and forth through these networks.

Or at least that the experimental design suggested that they were moving through these networks.

That was so mind-blowing.

The other story that was competing for the cover of Nature was the genome of the fruit fly.

It was the first time anybody had done a whole genome sequence of an organism.

There was the picture of the birch and fir instead of the fruit fly and I was like oh!

Because it was so mind-blowing.

>> Wow!

There was push-back then.

There continues to be push-back obviously.

One quote, "We can't publish articles by people who just dance through the forest looking at trees."

Description of you, supposedly.

Still, people saying now the science is scarce and unsettled and we can't base policy on it.

You've had a lot of people criticizing-- attacking your work.

>> Yes, that's right.

Even recently,there's been an attack on my work.

Science is an evolving thing.

There have been many experiments, honestly.

I have done 100's of experiments and dozens showing that this carbon, water or nitrogen can move from one tree to another.

What we found is that the amount that moves ranges from a tiny amount to quite a large amount.

In my studies, up to 10% of the carbon that's fixed in that group of plants or through photosynthesis is moving backing and forth between these trees.

In another study in Europe, where they did labelling of large trees, they're finding 40% of the carbon they think is moving between the trees through micorrhizal networks.

There is a lot of evidence that shows there's a lot of movement below ground.

A lot of it is moving through these networks.

Part of the issue comes from, can we see them?

Do we believe this?

Honestly after 30 years of studying this, I'm at the point where we have to recognize the complexity of these interactions, conversations between trees.

It's part of how they live as forests.

That they are in communication, that they are constantly attuned to each other through this back-and-forth movement.

When we know that and we are clear-cutting forest and taking down the big old trees, as well as everything else in that clear-cut.

That we're really undermining the ability of the forest to recover from this.

Because the network is such a fundamental process to the growth and recovery of a forest.

The critics also say we don't know enough to act on this.

Well, the status quo is to take out all the trees.

Is that not something we should act on for many reasons and this is one of the many reasons that we know that these old trees are important or these communication pathways are really important in the recovery of the forest.

>> You began to focus on those big old trees.

That you call hub trees.

You said at one point, Because I guess they have different pronouns.

But mother tree is where you settled.

>> Yes, the reason for that is, as you said, the field has been controversial.

At one point, I was getting so tired of the controversies.

About the argument-- is this real or not, what does this matter?

I thought, let's just make a map of what the network look in the forest.

What we found in making the map of the network is that looking at one fungal species using very highly technical DNA analysis, that all the trees were connected together by these micorrhizal fungi.

That the biggest trees were the biggest hubs of those networks.

They really stood out as linking all the trees, so many trees in the forest.

And smaller trees were also in that network but they had smaller roots systems.

They didn't have as many linkages as the big old trees.

These big old trees emerged as the lynch pins in the forest, the key connectors in the forest.

What we found is the survival of the seedlings that are linked into the network of the old trees is much greater than survival of those that are not.

In fact, if they don't link into a network and become colonized, they die.

I started calling them mother trees because they were nurturing the forest.

>> It's interesting how popular culture has embraced the idea so readily.

We saw Avatar ...you must have loved the Tree of Souls .

The Ents from Lord of the Rings .

The Overstory , the Pulitzer Prize winning book.

You're kind of a character in that book.

I was watching Ted Lasso the other day and heard your name.

It's interesting.

Are people inclined to believe this?

Do they instinctively know this?

Why has popular culture kind of latched on this more while there's still some controversy in science?

>> There's a number of reasons.

One we are social creatures.

We understand how those relationships work.

We understand that we're relational to people around us.

We are affected by our community, we affect our community.

That a forest would have those qualities as well, really resonates with us.

People being in the forest, they feel the essence of a forest.

The emergent things that come out of a forest-- the clean air, the smells.

That it's more than just a bunch of trees.

It's a whole forest, a whole social community.

We get that as people.

The other thing is we're in this moment, in history, where climate is changing really quickly.

We're seeing our landscapes being clear-cut.

We're aware as people, as humans, that there are big changes happening.

What happens in forests are very much connected to that.

We know that when we clear-cut forests, we are actually adding to climate change.

We're reducing our ability to mitigate climate change.

There's a lot of worry on one hand and there's a lot of innate knowledge as creatures of this earth, of social creatures.

It's that moment of realization we really need to start treating our forests with more respect because they're so essential to life, our life, on this planet.

A good way to think about that is when a tree breathes out oxygen, we breathe it in.

We're connected.

>> And indigenous knowledge.

Obviously you've spent a lot of time with Nations of British Columbia talking about this and your mother tree project.

There is a connection.

>> Yes, very much.

I am working with Nations in British Columbia in trying to protect the remaining mother trees.

Keep in mind again, we're still cutting down these ancient trees every single day.

We're not honouring those connections that we need to be intact in the land.

We have not been honouring the land.

I'm working with the Nations to try to mitigate that-- to stop the clear cutting.

It's got to stop.

There's a realization politically, certainly there's a realization socially.

That people know and so government has got to keep up with the people and what we want.

>> You probably were put on this planet for this cause.

>> Well, I feel like I was actually.

>> Do you think this is a mystery or ultimately knowable?

>> It's ultimately knowable.

There's going to be things we don't know.

That's the beauty of life right.

That's all the things we marvel at.

How is there a dawn chorus in the morning when you wake up?

All the birds are singing and it's a symphony.

Things that we don't know.

All those relationships between the birds and the trees.

Some things were not going to know but we know enough to change what we're doing now to protect our future generations.

We know enough we need to save these old trees, to stop clear-cutting the remaining old-growth forests, to restore forests.

So that they are carbon sinks again and homes for bio-diversity.

We can act on that.

That's not rocket science.

That's just good thinking.

>> The question we ask at the end of every interview is what does being Canadian mean to you?

>> I've always been very proud to be a Canadian.

I feel so connected to the land.

I grew up in the forest.

I feel like we have this place to discover, to explore, take care of, be responsible for.

I feel a great pride in taking on that responsibility.

I'm proud that we have a great diversity of people here.

We have First Nations whose livelihoods are still intact more or less.

That they can recover what they've lost in a large way as well.

I'm proud of our truth and reconciliation intentions.

I really want that to be successful.

I think that it's something we can be as leaders and be proud of our successes in those areas.

All of that together is part of being Canadian.

>> It has been a pleasure talking to you, >> Thank you, Suzanne.

>> Thank you, Valerie.

It's been really fun.

>> And we'll be back next week with another episode of Canada Files .

♪