Intelligent Trees (2016) - full transcript

Trees talk, know family ties and care for their young? Is this too fantastic to be true? German forester Peter Wohlleben ('The Hidden Life of Trees') and scientist Suzanne Simard (The University of British Columbia, Canada) have been observing and investigating the communication between trees over decades. And their findings are most astounding. 'Intelligent Trees' features the main observations that are covered in Peter Wohlleben's book such as the stump that has been kept alive by it's neighboring trees, the old tree-couple that looks after each other, the Mother Trees that suckle their offspring, etc... Special about this film is, however, that it goes beyond observations and claims, but match them with the latest underlying Forest Science Research.

We are a connected society.

We are connected to our families and friends,

but also to our jobs and duties.

We are connected over computer networks,

phone lines and traffic junctions.

The world surrounding us

is in constant movement and growth.

We left our houses made of wood

to plant an artificial forest

from concrete, glass and metal.

It's not easy escaping a world

where everything is connected

to spend some time in the forest

where we seek quiet and rest

from our unsteady lives.

We expect to find some kind of wisdom

in the forest,

but we don't understand the voice of nature.

If those trees could only talk!

Little do we know,

that in between this world of stillness,

words are rushing back and forth.

We only have to tilt our heads down

and listen … to our roots.

The Coastal Pacific Rainforest of North America.

These forests are special

and known all over the world.

Here in British Columbia,

one can find trees of heights

around a hundred meters

and over a thousand years of age.

People walk amongst these ancient giants

in a sense of spiritual wonder and respect.

But not anymore are these places

only described by mythological metaphors.

Scientists begin to understand the importance

of these forests as they discover more details

about the relationships between trees

on a microscopic scale.

Here in Canada,

at the University of British Columbia in Vancouver,

Dr. Suzanne Simard, Professor of Forest Ecology,

conducts groundbreaking research.

Together with a team

of passionate forest scientists

she tries to find out more about the methods

of communication amongst trees.

Before I became a professor

I was actually a forester.

And before that I grew up

in the Inland Rainforest of British Columbia.

As a forester I really was moving

into an area that I loved dear to my heart.

I knew forests.

As I started working for the forest industry,

I started to realize

that what was happening

didn't mesh very well

with what I understood forests to work like.

My job was to go into old clearcuts

or new clearcuts and prescribe

trees to be planted.

What the forest industry was doing then

was planting one or two species

in clearcuts.

This was very different than what I

understood forests to grow like,

where there is mixes of species.

When we go walking in the woods

we expect to find nature untouched

and pure, but in fact

we wander through an environment

that has been largely shaped by men.

Pristine forests are rather unique in the world.

In a small country like Germany

forests have been intensively managed

by people for centuries,

almost everywhere you go.

In an old, close to natural beech- forest

in The Eifel, a low mountain range

in the West of Germany,

forest ranger Peter Wohlleben

is well aware of the value

of the trees in his district.

For more than two decades

he made his observations.

In his bestselling book "The hidden life of trees"

he describes the most curious

and unexpected things

that are going on in his forest

He knows that this place is a rare treasure

that needs to be protected.

Originally all of Germany would have looked

like this old Beech-forest.

Eighty percent of the area was covered

with natural Beech-forests

mixed with other tree species.

But today there is only a fraction left

and we have plantation forests everywhere.

These consist mostly of plantations

with even-aged conifers that have been planted

and are managed with heavy machinery.

What happened was that they ended up

using the same species everywhere.

The standard practice was to clearcut

and then plant either pine or fir or spruce

One species. And I was wondering

what was going on.

The community was not intact any more.

It was much different

than what I grew knowing about these forests.

I studied forestry

and started my career the classical way:

I prescribed small clearcuts,

cut down such beautiful old beech-trees

like these, and used insecticides.

As a teenager I wanted to become

a conservationist.

But I started to realize that I was in fact

destroying everything

and that wasn't what I wanted.

When I looked at those trees I found

that they didn't perform that well.

They didn't grow very well.

They were sickly. They weren't that healthy.

As I became a scientist

after a few years as a forester,

I started to examine why these trees didn't seem

to grow well when they were by themselves.

I found that when we remove certain species

or their neighbors that trees actually became ill.

They became diseased and more at risk of insect attack.

I wanted to understand why that was the case.

I thought some of the story

might be going on below ground.

What we call a tree is only

what is visible above-ground.

We consider a tree to consist only

of trunk and crown.

However, the major part of it's life

takes place underground.

What happens in the forest

is actually more than whats meets the eye.

The root system of a tree

can spread as far as two to four times

the diameter of it's crown.

Only scientists with state of the art

research techniques are able

to dig deep enough into this matter

to uncover that these roots

are more than only water pipes.

I started looking at the root systems

I found that the roots of these different

tree species, when they grew together,

Birch and Fir and Cedar and Hemlock

were all intertwined and linked together.

I learned later on through more research

as I went into my PhD

that these rootsystems actually formed

what is called a Mycorrhizal Fungal Association.

Mycorrhizal fungi are certain species of fungi

which associate with all of the tree species worldwide.

They form a mutualistic relationship

where the fungus grows into the root

and provides the root with nutrients

and water that the fungus gathers up from the soil.

Mushrooms are only the fruiting-bodies of fungi,

just like apples are the fruit of apple-trees.

Fungi are very underestimated organisms,

because so far most of us appreciate only the fruit.

Fungi can spread over several square kilometer.

One teaspoon of soil may contain

several kilometers of string-like hyphae

that form the 'Internet of the Forest'.

For their services they charge sugar

and other products of tree-photosynthesis.

The tree shares up to a third

of it's total production with the fungi.

We found, when we mapped these forests,

that all of the trees were all

linked together in a single massive network.

I was wondering, how these below-ground linkages

would affect how trees are growing.

We did some more sophisticated experiments,

once we knew that those links existed.

We labelled one tree with an isotope

and traced it from that tree to it's neighbor.

We found that carbon molecules

were moving from one tree to another tree

through these mycorrhizal networks.

As we went one we thought

there might not only be carbon,

but other molecules involved as well.

We started labelling trees

with Nitrogen and Phosphorus and deuterated water.

We found that all of these elements

move back and forth between the trees.

That was the rudimentary

understanding of the language of trees.

So these birch trees here

will be linked to other birch trees,

but also to the Douglas Fir

and the Hemlock behind it.

You can see their root-systems

coming down there.

They straight into the ground.

The mycorrhizal network is just below

the surface of the forest floor.

As you walk, you are only centimeters

or millimeters away,

walking on top of this network.

The network below ground can easily be imagined

as a market place, where the food is either offered

or received by all the trees that are linked together.

But what about competition?

If all are eating at the same table,

then why don't they steal from each other

and suck each other dry, in a struggle

for the survival of the fittest?

Trees of one species are not competitors.

On the contrary: They actually support

each other almost unconditionally.

The weak are supported by the strong.

Only together they can, for example,

regulate the micro-climate

and lower the air-temperature,

because trees love it cool and moist.

You could almost call this 'tree-communism'

and it functions perfectly,

compared to human-communism.

Here, the individual is not as important as the community.

Trees do care for each other.

We think of that as an interaction between trees,

but they're looking after each other.

Sm’hayetsk d’waiyu.

Na walp Xpe Hanaax da wil tsogu.

Gitlan, Tsimshian da wil waatku.

My Name is Sm'hayetsk.

I'm Teresa Ryan. I'm Tsimshian.

I'm from the Gitlan tribe of the Tsimshian.

My house is Xpe Hanaax.

I'm from the Ganhada Clan; Raven.

My interest in research is the relationships

of the forests to Salmon.

I'm a Fisheries Scientist.

A Fisheries Aquatic Ecologist.

I'm also a Cedar Weaver.

A traditional Tsimshian Cedar Weaver.

We have an understanding of

these ecosystems around us

and the relationships with things within them.

In many of our languages we have

certain words to discribe that.

In Sm'algyax we say "of one heart".

The aboriginal people on Vancouver Island

say "Everything is one".

It demonstrates those relationships

that we've known and understood

for a long time.

When we mistake trees for loners,

each of them growing by themselves,

oblivious to their neighbors and to the environment,

we underestimate them by far.

If forests are actually not the kind

of harsh environment we expect them to be.

Where competition determines the survival

of the strongest, fastest and toughest,

then maybe a closer look might reveal

even further relationships

that go beyond our expectations.

The forest industry wants trees to grow quickly.

Initially trees do grow quite fast,

when they grow by themselves.

However, that is not what they prefer.

Normally, trees would rather cuddle

and stand closely together.

They love company and like to take things slow.

We need to relearn that trees do not need

to be separated from alleged competitors.

On the contrary: We need to allow them

to live in tight groups - just as they like it.

There is in fact friendship among trees.

It doesn't happen very often,

because tree seedlings cannot choose

whom they will be growing next to

for the rest of their lives.

Maybe one out of fifty trees will become

friends with it's neighbor, like these two.

They grow their branches away from each other

so that they don't interfere.

Their roots intertwine intensively.

It's like an old couple.

If one of them dies, the one left behind

might suffer, and die soon after.

For a tree it is a disaster

when the social network collapses.

You can observe this right in this forest.

Three trees have blown over.

The remaining tree is now left by itself and get's sick.

The tips of it's branches die back,

the leaves turn earlier in the fall,

so it can't photosynthesize properly.

It really suffers.

In case it is not able to reconnect

with other trees, it will likely die as well.

Do trees have a sense of friendship?

It's language that we are using here

to describe how trees relate to each other.

In ecology we call this interactions.

Interactions is a very clinical term.

When we think of interactions,

we think of: Do they help each other?

Do they compete with each other?

Is one a parasite or a pathogen?

Species interact in a myriad of ways.

Some of them are beneficial.

In Science this is called Facilitation.

In human relations we call that friendship.

A grove of Maple Trees with Cedar in it

will indicate to us

that the Cedar has enough moisture.

When Cedar and Maple are growing together,

there is a relationship with those two trees.

So it's just a matter of language.

When I think back to my early work

with plantations and we were planting single species

of trees and weeding out the species we didn't want,

I found that Douglas fir would suffer,

when we took birch away from it.

We were affecting that facilitation between them.

The transfer of Carbon back and forth,

the nutrition that the birch provided for the fir.

The resistance against the pathogens

that were in the soil.

When we took the birch away,

Douglas fir lost it's friend.

They lost it's facilitator.

So is there friendship in forests?

I can use that language.

Sure, there is friendship in forests!

There are mutualistic facilitative relationships

going on all the time.

Tree connections may form bonds

of friendship, but they also link each tree

to all the others over hubs,

very similar to a computer network.

Scientists who try to visualize these connections

have been creating complex models

that look like a map: A map of the Wood Wide Web.

By looking at this map we were able to identify,

which trees were the most important

part of the network.

Which ones were the most highly linked.

We found that the biggest, oldest trees

were the most highly linked.

We ended up calling them Mother Trees,

because we discovered through this map,

that the younger ones were growing up by

hooking into the network

and growing up around these Mother Trees.

Trees are very social beings.

The parents, the Mother Trees,

are looking after their offspring.

Their roots grow together

and they feed them with a sugar-solution.

One could say that the Mother Trees

'suckle' their offspring.

To some it may seem strange comparing the flow

of nutrients between older trees and their kin

with human relationships.

Analogies like that

based on the observations of a practitioner

should rather stand on a solid ground of scientific facts.

At UBC, students from the faculty of forestry

conduct basic research about the relationships

between Mother Trees and their kin.

All of our experiments involve both field

and greenhouse experiments.

We use similar techniques in both;

to verify what is going on in the other one.

We go into a Douglas fir forest to gather soil.

That soil has a mixture of mycorrhizal fungi

that prefer to associate with Douglas fir.

We use that mixture to inoculate our trees.

We grow 'Mother trees', basically seedlings

in pots, inside mesh-bags.

These mesh-bags would either allow

the mycorrhizal network to form

with the neighboring seedling, or not.

We use mesh-bag to keep the roots

from going through and touching

each other and transferring between roots.

We want just the fungi to meet in the middle.

Over a period of a few months,

we allow these two seedlings,

the 'Mother Tree' and her kind,

or the 'Mother Tree' and the stranger,

to communicate with each other

through this mycorrhizal network that had formed.

We had to be able to do the experiment

in the greenhouse, so we couldn't bring in

a big, old Mother Tree and plant her in a plot.

We had to use seedlings,

because of the restrictive environment of a greenhouse.

The seedling that grew up first

was well established and had more nutrients

to spare than the one that was planted later.

That one that was previously established

had more resources than it needed.

It was able to shuttle some of those resources

to it's little brother that was growing up next to it.

The term Mother Tree is a really nice term,

because we understand the importance

of mothers in families.

It's a term that resonates with people.

But it's probably not the most scientifically accurate term.

What we are really talking about is relatedness.

whether Mother Trees are related

to trees around her or new trees

that are coming up in her neighborhood.

It's really about whether their genetics

are well related to each other or not;

whether they are distant or close together.

One of the differential responses was:

When the new seedling,

the younger sibling if you will,

was planted that the older and bigger seedling

it was related to, slowed down it's growth rate.

It appeared that it would make room

for it's younger sibling to grow.

We would label these mother trees with C13;

which is an isotope that we injected

into a plastic bag around the seedling.

That bag completely seals in the air.

Then we allow the seedling to photosynthesize.

As we apply the treatment,

the seedling is only able

to photosynthesize with C13.

Any sugars, any products that it makes will be labeled.

Then we look for that C13 in the recipient plants.

Remember the recipients are either kin or stranger.

Then we'll look at the ration

of the amount of carbon that is present.

We bring the pots into the potting room,

we clip them and then we clean all the roots,

we brush-off all the dirt,

we wash them and then they

are ready to be morphotyped.

We do that using a microscope;

we look for all the fungal connections

on the root-tips. After that

they are ready to be dried.

We do that in a large drying oven.

After that each one of those

portions is frozen separately

using liquid nitrogen.

Then you are able to grind them

using mortar and pestle.

That creates a powder

that is weight in very small increments.

We send those to the lab

to evaluate how much C13 is in the sample.

And we found out that seedlings

that were kin seedlings

were receiving more Carbon

from Mother Trees than strangers were.

Then it starts to look like a family.

The Mother Tree is nurturing her own family

but she is also looking out for her whole neighborhood.

So it's not just a family.

It's a whole community of trees.

Each with their own role to play in the forest.

Mothers who care lovingly

for their neighborhood and their children?

Also Peter Wohlleben has a way

of expressing the behaviors of trees

in a very humanized language.

When guiding groups of visitors through his forest,

this helps to make biological mechanisms

understandable for everyone.

When he talks about tree families

he goes further by claiming

that they even provide a good education.

This is a typical Beech-Kindergarten.

Beech-trees grow up in groups

just like this one.

The parents raise their children very strictly

by limiting the available light.

Only three percent of the sunlight

reaches the ground, so that the small trees

need to stretch towards the little remaining light.

The benefit of this is

that they grow straight trunks,

which can resist strong winds.

However, like in every class or kindergarten,

there are little rascals that do as they please.

They grow this way, they grow that way,

they think 'Oh I don't have to stretch towards the light'.

Slowly their class-mates surpass them

and switch off the last bit of light,

so that they die off.

Eventually from this entire bunch

only one or two trees will remain to grow old.

We discovered that the Mother Tree

was affecting how those seedlings grew.

So if we changed the linkages

or we removed them,

those seedlings would behave differently.

They would either grow worse

or they would grow better.

What we were gathering from this:

If the Mother Tree was trying

to make a favorable place for their seedlings

then she would encourage their growth;

so send more nutrients to those seedlings

and they would grow better.

If the Mother Tree knew

that the environment around her

was not ver hospitable for her young

in other words, if there were diseases

or insects around,

she would it make more difficult

for those seedlings to grow.

She would be antagonistic towards them

or become more competitive.

This said to me

that the Mother Tree was communicating

with her young, in order to favor

the survival of those seedlings;

whether they should be further away

or close to her depending on how

favorable the environment was.

We are doing these experiments

out in the forest as well.

So we'll go to big, old Mother Trees

and grow seedlings that are related

or distantly related to her

and see how they perform.

So we will verify,

what we are seeing in the greenhouse

with what's going on in the forest.

Trees are studied and measured,

cultivated and cut.

They seem defenseless,

because they can't run away from any thread.

Some plants, however, have developed

amazing skills to react to attacks.

The response of this mimosa

makes it obvious

that even plants don't like to be hurt.

Trees have feelings.

They can feel pain,

but can also have emotions, such as fear.

This is apparent, for example, in this oak behind us.

It grows these clusters of twigs;

signs of great distress.

But the oak would behave differently,

if, for example, attacked by insects

that bore into it's bark.

It would feel pain, electrical signals would run

through it's fibre and the oak

would accumulate defense substances.

At the same time it would alarm it's colleges

via root network and fungi,

so that they could already accumulate

defense substances, although

they haven't been attacked, yet.

Once the insects arrive,

the other oaks would be prepared.

A forest is much healthier and more resistant,

when individual trees warn the rest

of the community,

as soon as they realize something is wrong.

At the same time that we were looking

at Carbon transfer, or this energy transfer,

we were also looking at defense signal's transfers

through these mycorrhizal networks.

It's mysterious that a plant

would leak these particular compounds

and that a fungus would pick them up

and transmit them through their hyphae

to another plant.

We haven't seen this before,

this flow of signaling molecules.

We're trying to figure out

what these defense signals are.

We have an idea that there are certain

compounds involved.

What happens is that the injured seedling

sends defense signals. The seedling

that receives the signal, or that

piece of communication,

those words, if you can think of it that way,

Then they up-regulate

their defense genes. Those genes

start to produce more defense enzymes.

Those enzymes increase the defense

of those seedlings against the attack

by those insects.

When you are scared,

your body is producing chemicals

that are telling your whole body

that you are scared.

It's getting your legs ready to run,

it's getting your arms ready

to whatever they need to do.

Those chemicals are specific for that purpose.

If those would leak out of your feet

and something in the ground,

let's say a fungus,

would pick up those chemicals

and transmit them through the ground.

so move them through the ground,

and someone else standing nearby

would pick up those chemicals through their feet

and get scared,

because they would get those

scary chemicals in their body.

That's like what like what we

are looking at with the trees.

This guy get's scared

it's sending those chemicals

among it's own body and then

they go out into the roots.

The question is, whether the fungi,

which are an entirely different organism,

not a tree,

are moving those chemicals

through the ground and if those

are being picked-up by the other trees.

Specifically, I am looking at

defense signals, which I

induce using Western Spruce Budworm

onto Douglas fir.

The tree that has the Western Spruce Budworm

elicits a response from the tree,

which is sent into the mycorrhizal network

and get's transferred to an adjacent seedling

that is attached via a mycorrhizal network.

Two plants in a pot.

They are Douglas fir seedlings;

which is what we tend to use,

because they form strong mycorrhizal networks.

They are planted inside mesh-bags.

Those mesh-bags can either be very small

in their pore-size and block mycorrhizal networks or

a bit larger and allow mycorrhizal networks.

So, we compare treatments, where they are networks

to treatment where there are not,

and see if that transfer occurs.

This is where we place the Spruce Budworms

and entice them to eat these little budding areas.

You clip off the branches

and then you dip them in liquid nitrogen.

You scrape off the needles

and put the stem in another vile.

You dip it in liquid nitrogen,

because you want to freeze what is happening.

You measure gene expression

by looking at RNA,

which is a really short-lived chemical.

It can degrade very quickly.

You want to take it off the live plant

and dip it in the liquid nitrogen

as fast as you can.

The defense signals, or the warning signals,

are happening really quickly.

So when there is an injury,

there is an almost instant communication.

There is an immediate up-regulation of genes

that increases the defense.

It is actually knowledge that is being passed on,

from the seedling that is injured to the new one.

That knowledge, is based in wisdom.

I think of it more as passing on wisdom.

(Burial Forest)

It's important for a forest

to sustain all of it's members;

including old and dying trees.

Even stumps that you would expect

to have died hundreds of years ago,

are being kept alive.

Possibly, they have stored memories,

that they can pass on.

This is an ancient stump;

and it is still alive.

The inner part of a tree, the heartwood,

is without life; much like dead bone.

That's why this one is rotten inside.

In trees, life is located in the sapwood,

in the cambium and in the roots.

And all of this is still alive in this one here.

The question is, how can this be possible?

It doesn't have any more leaves

to photosynthesize and nourish itself.

Still, it must consume sugar,

otherwise it would die.

The only possible explanation is

that this tree over there,

keeps the stump alive via root connections

that are running across here.

It appears very social and touching

that this old stump is still being nurtured.

The forest's own 'nursery home for the elderly' .

When trees are cut,

fall over or break over with the wind

that the stump continues to live.

We can tell that it's living,

because the cambium in the bark

grows over the top of this stump.

There is no way it will grow into a new tree,

because is there is no seed

or there is no epical meristem there.

The stump is still alive,

because it's root systems are grafted

to it's neighbors,

or they are linked in

through the mycorrhizal networks, or both.

When you have that pathway,

the trees that are alive around it

are sending Carbon from the foliage

down into the root systems of the stump

and keeping that stump alive.

Where does a tree store it's information?

How valuable is such a stump to the community?

So far, we don't not known where a tree's memory

is located and where it stores experiences.

For example, droughts that occurred

a long time ago can influence

a tree's behavior over many years.

This demonstrates that they store

this information somewhere.

It is quite likely that this storage sits

partially or even entirely in the roots.

An ancient stump like this

might pass on it's knowledge

to the neighboring trees and it's descendants.

It is now known, that processes occur in the root-tips,

which are quite similar to those of a brain.

Obviously it is presumptuous to claim

that trees have a brain just like animals.

However, they make decisions within seconds

that are partially processed electrically.

All of this takes place in the roots.

So maybe, we could call this a tree-brain.

Through these various experiments

and our discoveries, I've started to think

about the root systems of trees in forests

as the brains of the forest.

There is a number of reasons for this.

First it's the pattern of these connections,

the pattern of the network.

When we look at how it's arranged,

it's very much like how our brain is organized.

There are certain central hubs in forests,

where things are highly connected.

Then there are satellite nodes,

where things are less connected.

If you look at a neural network,

it's patterned very much in the same way.

Secondly, the idea that there are chemicals

that are transmitting from a mycorrhizal root-tip

or root of one tree through the mycorrhizal network

to another tree.

This is like in our brains.

We have neurotransmitters.

It's not that much different than

Carbon, Methyl Jasmonate, Nitrogen and Water

moving back and forth through these

mycorrhizal networks.

There is another part to the story.

In dying pine forests, for example,

that are attacked by Mountain Pine Beetle,

those dying trees affect the mycorrhizal communities.

Seedlings in healthy forests

have a better suite of defense enzymes

than those from dying forests.

We know that it's not only a Carbon legacy

that is passed on, it's also messages

about he defense chemistry

of the new seedlings coming up.

We really need to think more carefully

about how we manage these dying forests.

We will be dealing with this more and more.

Tree species will be changing as the climate changes.

There is going to be a mortality.

Our response has been to cut those trees down

as quickly as possible, make them

into two-by-fours and sell them.

You can easily see that by doing that

we're cutting off the opportunity

for the old trees, the dying trees,

to pass their legacy onto the new generations.

When we cut down trees,

not only do we disturb the micro-climate of the forest,

but also the relationships between the trees.

They become loners,

and we won't be able to observe

these wonderful processes any more.

Managed forests are a convenient way

to transform the natural disorder

into efficient, fast growing plantations

of rogue trees.

Its getting quiet.

Planted forests don't talk much.

Plantations are like a group of only-children

without parental guidance.

These trees are planted

with clipped and damaged roots,

which results in disrupted communication;

along with many other dysfunctions.

The trees are forced to fend for themselves,

which leaves them more vulnerable.

If a tree suffers,

it won't receive help from it's neighbors.

If one thrives, and could share,

it would rather grow a little faster,

which is also not healthy.

In a forest, speed is always negative.

In Germany are no more pristine forests left.

In the past centuries numerous activities

took place everywhere in the forests.

Here, for example, charcoal production

took place.

This forest will likely be

very close to natural again,

in about one-hundred to two-hundred years.

Only very few places like this

still exist in Germany.

But currently the forest industry

is becoming increasingly radical,

and more and more wood is being harvested.

Sadly, we are turning back the clock.

These plantations are increasingly managed

with heavy machinery.

And these machines compress the soil.

They destroy the pore-volume

and life in the soil suffocates.

This includes also the fungi

which are extremely important

for the communication between trees.

Most machines have wide tires,

so damage caused is often

not so visible on the surface.

However, compaction remains

and increases with the size of the tires.

The soil becomes compacted down to two meters.

This is comparable to a sponge

that has been squeezed.

But unlike a sponge soil doesn't recover.

Pore size is lost along with oxygen-content.

Compared to before, in some cases,

only as little as five percent of the water

can be stored.

This is extremely dangerous for trees,

because here, during summer,

trees depend on winter-precipitation.

And if this can't be stored any more,

the trees may die of thirst during summer.

And according to geologists,

soil damage below twenty centimeters

remains beyond repair, until the next ice-Age.

In horse-logging, harvested stems

are first cut to a maximum of five meters;

a length that a horse can handle.

The horse navigates gently

around both big and small trees,

and barely causes any damage.

Even today, horse-logging

could be done on a large scale.

However, most horse-loggers don't find enough work,

because there isn't sufficient demand.

One could argue that if all of the harvesting

would be done only with horses,

it would exceed the number of horses available.

That may be true, but when the demand grew,

more people would be motivated

to practice horse-logging.

It is a wonderful job that has already

been practiced for thousands of years.

I am certain that today

it can be just as successful.

Obviously we would need more personnel

to replace large machinery.

One harvester replaces twelve workers.

So - if we would turn back time

we could create twelve new jobs.

Interestingly enough this pays off:

We earn more, because we preserve the soil

and the forest is more productive.

It grows more wood in better qualities,

while we generate more jobs.

More money, more jobs. I like that.

We didn't treat forests like families at all.

We've treated them like rows

of corn plants, basically.

This new understanding that we suddenly had;

that Mother Trees were linked to all these seedlings

and other trees below ground and favoring her kin,

completely turned the idea of how

we manage forests upside down.

Now, instead of rows of trees,

it's families of trees.

How you treat a family of trees

is going to be very different

than how you would treat individual rows of trees.

As a forester, you like to think

that you are helping the forest,

but in fact it's comparable

to a small child that fiddles with a clockwork,

thinking that it can make it run smoother afterwards.

That means we need to keep out

of such an ecosystem if we want it to function.

We can take something, every once in a while.

But once we start to destroy things,

we will eventually reach a point of no return.

We as humans make great demands.

We want to be warm during the winter,

so we heat our homes with wood.

We want furniture, we want to use paper.

That is OK, but obviously this clashes

with the idea of an intact forest.

We should be aware that when we use a chainsaw,

we can't be doing any good.

We pretty much slaughter a tree.

As long as there is a certain limit to it,

the forest will be able to cope.

But if we take too much, it will be destroyed.

What every single one of us can do

to take better care of the forest,

is simply to reduce consumption.

With over seven Billion people,

we can't keep going on at this level.

Is this a Survival of the Fittest after all?

We use trees to provide wood

for our homes, which we then build

where once these trees used to be.

Our cities grow and displace the forests.

Have we unwillingly turned to enemies

who compete for the same ground?

Is there an alternative to how we treat forests;

so that we are able to coexist

and preserve what is still left?

In the world of forestry,

Foresters generally don't pay any attention to it.

They either don't know about it

or they're so wrapped up in the traditional ways

of practicing forestry.

They've become so rigid in how they do things,

that the idea that things can be connected below ground

and therefore, to conserve those connections

would mean doing forestry in a very different way.

We need to change terminology.

We shouldn't claim

that we are tending to the forest,

when we are in fact utilizing wood.

Just as a butcher is not an animal-keeper,

a forester is no forest-keeper.

Once we realize that we always destroy something,

when we use a chainsaw,

we might start to treat the forest more carefully.

I think that there is an enormous opportunity

to transform how we practice forestry,

so that our forest are more wise,

have their language intact,

have their families intact.

They'll be around in the future.

Where as the planted forests that we are putting back,

where we don't conserve those features,

or those qualities of a community,

will be way more at risk.

Just like, if we become isolated in our societies,

we are more at risk.

It's not any different than forests.

The Municipality of Hümmel,

where I am forest ranger,

has placed all of their remaining

old Beech-forests under protection.

That's very rare in Germany.

At over two-hundred, these beech-trees,

are comparatively old.

Here, they can live their social lives entirely undisturbed.

Only in forests like this,

can one observe the intact social life of trees.

It is possible to manage forests so gently

that they can emulate pristine forest processes.

That means removing only single trees

here and there and leaving the rest

of this social community alone.

Planting, tending, producing great wood-qualities:

Trees can manage this all by themselves.

We can pretty much sit back.

When people hear about connections below ground

and that there is mothering going on in forests,

people immediate say:

Of course, I see this all the time.

I knew this all the time.

I am so glad that you've done

the science that validates

what I've always felt about a forest.

To me, that's hugely powerful.

There's already a sense out there.

We as humans are part of that forest

and what we'e perceiving is really valuable.

We should be paying attention to that,

because it's true. It's true in our hearts

and it's true in the forest.

To me that's a super-important message

that this is a natural fit.

It's a natural fit in forests

and it's a natural fit with how we interact

with forests. It's something we

can learn from forests to bring

to our own sense of community and family as well.

Hopefully scientists like Suzanne Simard

and observers like Peter Wohlleben

are able to change the way we look at trees.

Looking at nature has often helped engineers

to find inspiration for groundbreaking inventions.

Looking at the forest might inspire us to live

in a healthy human community that appreciates

the natural processes surrounding us.

Next time we take a walk in the forest

and ask ourselves if trees can talk,

the answer lies below the surface:

Trees do talk!

What they want to tell us remains

yet to be uncovered.

Maybe all they say is:

Let us be.

Can you imagine, being a tree

living by yourself?

Without neighbors?

Without others around to care for you?

Trees don't do well when they're by themselves.

They blow over, or they get too much sun

or too much water

or they're more at risk of getting a disease.

But when they are in a community

and they have neighbors around

that protect them;

really, they are caring for each other.

They're making sure that they

are a productive, healthy, vibrant,

diverse community of trees.

Families of trees.