
Exploring How and Why Trees ‘Talk’ to Each Other - bryanrasmussen
http://e360.yale.edu/features/exploring_how_and_why_trees_talk_to_each_other
======
two2two
If you're interested in this subject, Peter Wohlleben published a book in 2015
called The Hidden Life of Trees, What They Feel, How They Communicate. One
excerpt from the book relevant to this article:

"The fungus not only penetrates and envelops the tree's roots, but also allows
its web to roam through the surrounding forest floor. In so doing, it extends
the reach of the tree's own roots as the web grows out toward other trees.
Here, it connects with other trees' fungal partners and roots. And so a
network is created, and now it's easy for the trees to exchange vital
nutrients and even information--such as an impending insect attack" (51).

I look at groups of trees, and trees in general, very differently than I had
before I read this book. I'm happy to see this Yale article make it to HN.

~~~
dmix
Do you know how far from the tree do these network travel? Do the other trees
it 'communicates' with have to be right next to it or can they be some
distance?

As someone who has a passing interest in mycology I find this as much
interesting in how important fungi is to the world as are trees. It has many
proponents who believe fungi doesn't get enough credit for fueling the world's
ecology as plants and trees. Possibly due to mushrooms perception as being
harmful to humans.

Thanks for the book recommendation (Amazon link
[https://www.amazon.com/Hidden-Life-Trees-Communicate-
Discove...](https://www.amazon.com/Hidden-Life-Trees-Communicate-
Discoveries/dp/1771642483)).

~~~
gehwartzen
Yeah, I was just thinking how some of our seemingly established forestry
principles of thinning out overgrown portions of forests to keep it 'healthy'
or engaging in selective logging could be disrupting some of these networks.

------
bane
I think we have to consider using higher levels of abstraction when discussing
how organisms so far removed from our neighborhood of the tree of life deal
with experiencing the universe.

Instead of "talking" \- communicating

Instead of "feeling" \- sensing

Instead of "thinking" \- processing

And so on. We risk anthropomorphizing other living beings we can't possibly
relate to. Just as it's important we gain better understanding of how other
living things live, it's just as important to not apply how we live to them.

At worst we should talk about "analogs" instead of euphemisms. Does a tree
feel "pain" or does a tree feel a "pain analog"? The first is ascribing
something that may not even make sense, the second grounds us in comparisons
and looking for cause and effect analogs.

Do trees talk? No, they have no mouths. Do trees communicate? As we understand
these things more and more, it appears that there's some kind of analog there.

Do trees feel? Maybe that's the wrong question. Do trees respond to stimuli?
Of course!

~~~
dredmorbius
Fair suggestion, though "feeling" might be confused with _emotional_ response
rather than senses. _Perception_ is the general term in psychology AFAIU
(e.g., "perceptual psychology" \-- among my more surprisingly fascinating uni
courses).

But the breakdown is a good one.

It also brings to mind the _trivium_ from the mediaeval academic curriculum:
grammar, logic, and rhetoric.

 _Grammar_ is the process of _acquiring_ (and making sense of) information.

 _Logic_ is the process of _interpreting_ and _processing_ information.

 _Rhetoric_ is the process of _transmitting_ information.

Or: it's an input, logic, output sequence.

This can be applied to much of information-systems or information-theory work.
Perhaps with the addition of some endogenous or exogenous information storage
and retrieval system.

As for talking: the deaf speak, with their hands.

Symbolic representative abstract communication is just that. I'd argue that
the relevant element of _talking_ is the _interactivity_ of the conversation.

Take the old Unix "talk" command. It was contrasted to "write", "wall", or
"mail", in that _both parties could talk at the same time_.

Myself and my girlfriend, 800 km apart. That in the 1980s was mind-blowing.
And _much_ cheaper than long-distance telephony.

------
maxander
Carbon- and mineral-sharing between trees makes good game-theoretic sense. Any
two neighbouring trees could easily be neighbours for upwards of a century,
effecting and relying on the same soil; its an iterated "game" of extreme
duration and no option of escape. Cooperation is the overwhelmingly better
strategy in those kinds of situations.

~~~
roceasta
Exactly. Whereas cooperation between the trees and the pine beetles won't
happen because the beetles migrate.

------
thewayfarer
Absolutely fascinating work! However, I'm not entirely sold on the usage of
the term "mother tree." While Simard says

> That’s how we came up with the term “mother tree,” because they’re the
> biggest, oldest trees, and we know that they can nurture their own kin.

the interview doesn't reference any work that specifically states these mother
trees will preferentially nurture kin over other species. For example, when
she describes the more controlled greenhouse experiment with Douglas firs and
Ponderosa pines, an injured mother tree Douglas fir dumped carbon into the
network and the ponderosa pines still absorbed it. She may have other work
that describes some kind of kin preference, but I don't see it cited and I
don't quite understand what the mechanism to make this happen would be.

Rather, (as a layman without any knowledge of the work and published papers
around this topic), I see this phenomenon not as the result of "mother trees"
but from "farmer fungi." The fungi, because of their large networks and
relationships with the trees, become "resource managers" of the forest. The
fungi have an incentive to make sure that the trees are healthy and will
continue to provide nutrients for the fungi. When younger trees are injured,
that is a threat to the fungi's survival, and therefore one possibility is
that they have evolved this mechanism that transports resources from older
trees to the younger ones to help the younger trees survive. The relationship
between these fungi and trees are normally symbiotic, but the older trees
"tolerate" (or fail to evolve some immune response to) this mildly pathogenic
behavior because it _likely_ benefits its nearby offspring or close kin.

I think the concept of the "mother tree" _might_ be slightly anthropomorphic,
assuming that a large, multi-organ plant must be more intelligent and possibly
be even more caring than small fungi that must only be able to perform simple
functions. In reality, the fungi are the organisms in the best position to
evolve this beneficial behavior.

Again, I'm a non-expert with zero knowledge on this topic. If anyone could
provide a reference to a free online paper that describes these "mother trees"
as preferentially nurturing kin, I could be persuaded. And that would be a
very interesting read!

~~~
schiffern
These networks also transport signalling and defense molecules, which seem to
transmit kin selection information. They also (as you might expect) work
better on plants of the same species.
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4497361/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4497361/)

> _The relatedness of neighbours in mono-specific plant communities can also
> influence whether MNs will elicit adaptive behavioural changes. For example,
> foliar nutrition in AMF_ Ambrosia artisifolia L. _improved when it was
> integrated into an MN with related plants but not conspecific strangers
> (File et al. 2012). Likewise, in mono-specific pairs of EMF interior
> Douglas-fir grown in greenhouse conditions, foliar micronutrients were
> increased in kin compared with strangers grown with older conspecifics (Asay
> 2013). This appears to be linked with mycorrhizal association of this system
> as mycorrhizal colonization was also elevated in kin seedlings (File et al.
> 2012; Asay 2013). These findings reveal that MNs can play an integral role
> in kin selection, but the exact mechanisms by which they do this are
> unclear. However, there is strong evidence that biochemical signals derived
> from mycorrhizas or roots are involved. For example, Semchenko et al. (2014)
> showed that root exudates carried specific information about the genetic
> relatedness, population origin and species identity of neighbours, and
> locally applied exudates triggered different root behaviour responses of
> neighbours. This included increased root density, achieved through changes
> in morphology rather than biomass allocation, suggesting the plants limited
> the energetic cost of their behaviour._

> _Because the overwhelming majority of plants are predominantly mycorrhizal_
> in situ, _any root exudates involved in kin recognition are likely to be
> filtered through mycorrhizal fungi. In a recent study using stable-isotope
> probing, we found that MNs transmitted more carbon from older ‘donor’
> Douglas-fir seedlings to the roots of younger kin ‘receiver’ seedlings than
> to stranger ‘receiver’ seedlings, suggesting a fitness advantage to
> genetically related neighbours (Pickles et al. unpubl.)._ ...

An additional selection process could be as simple as spatial proximity.
Daughter trees are more likely to germinate close to their mother, and the
mycorrhizal network can be expected to conserve energy by transporting
nutrients no farther than needed.

Besides that, there's other evidence of kin selection in plants, in the form
of reduced root competition.
[http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12121/p...](http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12121/pdf)

But there's a broader point here. You're reading the word "mothering"
narrowly, only w/r/t/ the selection of individual organisms. But selection can
also take place on the whole plant community. Eugene Odum, widely considered
the father of ecology, points this out:
[https://www.youtube.com/watch?v=6P9V6h2z79w&t=3m15s](https://www.youtube.com/watch?v=6P9V6h2z79w&t=3m15s)
Plants can't get up and walk away, and polyculture plant communities are
healthier than monocultures. So I would argue that even in the hypothetical
absence of kin selection, "mothering" could take the form of encouraging a
diversity of species in a tree's immediate surroundings, making a favorable
local environment for their offspring.

~~~
thewayfarer
Brilliant and fascinating!

I thought the sentences following your second quotation from the first paper,
hypothesizing on the mechanism for kin selection, to be quite interesting:

> This may have been facilitated by the greater mycorrhizal colonization of
> kin than stranger seedlings (Asay 2013), creating a stronger sink in the MN,
> an effect also noted in the study by File et al. (2012). The greater
> colonization of kin seedlings may have arisen from complimentary genetics of
> the fungal genet and tree genotype (e.g. Rosado et al. 1994a, b).
> [...]although the mechanism through which the MN elicits the behavior
> response remains to be resolved.

This genetic mechanism makes sense to me.

The first paper talks about many rich, complex relationships. Two topics I
thought were very interesting:

> A fungus can express a mutualism with one plant, while simultaneously
> exploiting a different plant. Mycoheterotrophic plants are perhaps the most
> extreme example of this type of exploitation, where a plant acquires all of
> its carbon by parasitizing fungi through the MN (e.g. Leake 1994; Massicotte
> et al. 2012). These plants link into the MN of a nearby tree and siphon off
> photosynthate, enabling them to survive and grow. Importantly this reveals
> the existence of a mechanism by which plants can acquire nutritional levels
> of carbon from mycorrhizal fungi. The fitness of all participants in this
> scenario is increased by the existence of the MN: (i) the mycorrhizal fungus
> acquires carbon from the tree (or multiple trees) and may use the
> mycoheterotroph as the staging ground for long-distance exploration and
> colonization, (ii) the mycoheterotroph acquires carbon from the fungus and
> (iii) the tree gains access to a wider pool of soil resources, and
> potentially connection to other trees facilitating the detection of defence
> signals.

> There is evidence for both tit-for-tat and reciprocal altruism in MNs in
> forests, both which would be resistant to cheaters (i.e. individuals that
> benefit without reciprocating). Tit-for-tat, distinct from mutualisms, is
> evident in bidirectional transfer between paper birch and Douglas-fir
> (Simard et al. 1997a, b; Philip et al. 2010) and between unrelated Douglas-
> fir (Teste et al. 2010). This cooperative bidirectional exchange occurs over
> a period of a few days and appears to be related to the behaviour and
> possibly fitness of the individuals involved in the network. However,
> reciprocal altruism, or repeated prisoners dilemma, occurs over longer time
> periods, and this explanation is more congruent with the highly variable
> disturbances and hiatus in forests. There is some evidence for reciprocal
> altruism through the switches in the direction of net carbon transfer
> between paper birch and Douglas-fir (Philip 2006) or maple and trout lily
> seedlings (Lerat et al. 2002) in response to differential changes in plant
> phenology over a period of several months.

Your second paper on kin selection appears to be mainly theoretical on the
topic of competition theory, not an observational study of plants or fungi. It
makes weak conclusions like "It is reasonable to hypothesize that traits
expressed only in the presence of strangers may indicate competition or
selfishness, while traits expressed in the presence of kin may indicate
cooperation or altruism (Murphy & Dudley 2009; File et al. 2012)" and "It is
too soon to know if plant kin recognition responses will demonstrate the
breadth that has been found for kin selection in animal behaviour."

> But selection can also take place on the whole plant community.

No doubt.

~~~
schiffern
Crap, wrong link. This is the kin recognition root growth study:
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2104794/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2104794/)

PBS's _Nature_ did a whole documentary on plant behavior, which includes the
author of that study: [https://www.youtube.com/watch?v=CrrSAc-
vjG4&t=38m00s](https://www.youtube.com/watch?v=CrrSAc-vjG4&t=38m00s)

------
valarauca1
Prediction:

As we start to approach a true AI, I have a feeling a side effect will begin
to understand there multiple sentient organisms we simply dismissed due to
_some_ standard.

Much like how earth retreated from the center of the universe, to just a wet
rock orbiting a slightly above average brightness yellow dwarf.

~~~
ddebernardy
One big standard is the ability to recognize oneself in a mirror and, insofar
as I'm aware, humans are the only ones who have yet to pass it consistently.
(Perhaps a few great apes have done so since.)

~~~
hacker_9
No? The 'mirror test' has been passed by a range of animals, including apes,
elephants and dolphins.

~~~
seszett
But anyway it's obviously meaningless when we're talking about plants.

Blind humans cannot recognize themselves in a mirror either, but it doesn't
mean anything about their sentience.

~~~
rectangletangle
It becomes further confused when animals like dogs are introduced into the
equation. They fail the visual mirror test, primarily because vision isn't
their primary sense.

------
carapace
Living in harmony with Nature-- on a _scientific basis_ \--is pretty much the
most crucial challenge facing our (global) civilization right now.

I was just reading about Muir and his communication with the living Nature
around him. This isn't "mystic" mumbo-jumbo: many of the chemicals being used
in these tree+fungus networks are also used in our "internal" systems. We
speak tree on the chemical level.

\-------------------------------

I want to report on some events in a backyard here in San Francisco.

The western part of the city, from Twin Peaks to the ocean, is mostly built on
sand. Before the houses were there it was scrub and beach for more than a
mile.

The backyard in question consisted of this very sandy soil, with just enough
organic matter to bind it a little and turn it tan-brown. Some plants had been
set in years earlier, a couple of rose bushes, lilacs, some calla lilies.
Grasses and oxalis and some other things were doing their best, but there were
patches of bare dirt, and by dirt I mean of course just dirty sand.

So I went to the store and got a bunch of bags of organic hummus/mulch and
just plastered every open space with it an inch thick. It was rife with
mycelium and the fungus lost no time in binding and sealing itself together in
a single mass over the sandy soil. Realizing this I made sure to connect all
the patches together by thick bands of mulch so the whole yard could
communicate.

The specific thing I want to mention is this: After a few weeks, maybe less, I
was watering a patch of the mycelium mulch one day when I stopped and stuck my
finger into the ground to check absorption depth. While the surface was
completely wet, even drenched, imagine my astonishment when I found that just
under the surface less than a quarter of an inch down it was bone dry.

I watered that patch for a solid minute until puddles has formed in every
slight depression. Still it was completely dry just under the surface. But the
puddles vanished in seconds!

I watered it again, just dumping water on it from the hose. A certain amount
would puddle up, but the bulk of the water simply vanished. Gallons of water
and still the soil was bone dry just below the wetted top layer.

I poked around a bit more and found that the mulch had become nearly solid
mycelium bound around the little wood chips and other media in it. It had a
glossy sheen and was forming a sort of sheet or membrane rather than just
strands. The point is: that fungus had sealed the water off from the sandy
very-high-drainage dirt underneath and was channeling it somewhere.

There is much still to learn about how Nature works.

~~~
etplayer
> Living in harmony with Nature-- on a scientific basis --is pretty much the
> most crucial challenge facing our (global) civilization right now.

Social anarchist and proponent of ecological anarchism Murray Bookchin has
written about the challenges facing our current society and indeed produced by
it with regard to the earth's ecology. He writes,

>Social ecology is based on the conviction that nearly all of our present
ecological problems originate in deep-seated social problems. It follows, from
this view, that these ecological problems cannot be understood, let alone
solved, without a careful understanding of our existing society and the
irrationalities that dominate it. To make this point more concrete: economic,
ethnic, cultural, and gender conflicts, among many others, lie at the core of
the most serious ecological dislocations we face today—apart, to be sure, from
those that are produced by natural catastrophes.

Although I haven't started to read anything about his social ecological
theories, I have found him to be a good writer even if I do not completely
agree with him. I thought you would be interested. There's a bibliography on
his Wikipedia page:
[https://en.wikipedia.org/wiki/Murray_Bookchin#Selected_bibli...](https://en.wikipedia.org/wiki/Murray_Bookchin#Selected_bibliography)

~~~
carapace
I'm not unfamiliar with Bookchin, but his politics are not to my personal
taste

I really liked "The Ecology of Commerce" by Paul Hawken
[http://www.ecobooks.com/books/ecommerc.htm](http://www.ecobooks.com/books/ecommerc.htm)

To my mind it's well established that any political system that is out of
harmony with Nature fails eventually. Contrary-wise, ecological sanity is a
necessary (but perhaps not sufficient) condition for any political system to
succeed.

I dream of buying a large piece of land and living more-or-less in Nature, but
I also want to be able to call the sheriff or the ambulance for help if I
really need them, so I can't be completely immune to political considerations.

As a thought experiment, I've tried to come up with a "Minimum Viable
Civilization"...

~~~
philippnagel
Would you be willing to share some of your toughts on a "Minimum Viable
Civilization"?

~~~
carapace
Why certainly, how kind of you to ask. :-)

Pretend for a moment that you didn't like anything about modern civilization
and you wanted to go back to a neolithic existence. This isn't a stable state
though: after thousands of years people would forget about how bad things were
and start civilization over again. Put another way, it happened once, so what
would prevent it from happening again?

So we can't just set the clock back to an earlier idealized age. (Not least
because it would imply the deaths of billions of people who are today
dependent on the existing system.) Somebody somewhere would eventually
rediscover steam power and the feedback loop would begin all over again.

So we are stuck with it, and by "it" I mean technology. At the level I'm
talking about the details of the civilization hardly matter, it's the
technology that defines our ability to even contemplate living not-in-harmony
with Nature.

The Neolithic hunter-gatherer has a pretty sophisticated science and
technology for dwelling in the way they do: it is becoming more and more
widely recognized that such folk affect and adapt their habitat over time, in
effect gardening their world.

But they don't build skyscrapers, they don't launch rockets.

What is the essential difference between the technology of long-term
ecologically sustainable hunter-gatherer societies and the modern technology
we take for granted today?

Two things: Power, and motive.

Power, capacity to do work, I don't need to define. We burn trees, fresh or as
petrol, and eventually we harness the atom. Power is an unqualified good. It
has to be used wisely. (Ask the Aral Sea what happens if you fail.)

 _Motive_ on the other hand can be good or bad. The "motive" of the neolithic
society is to carry on in an eternal fashion, part of Nature, and so timeless.

The "motive" of current society, in contrast, is consciously or unconsciously
a movement from "the past" to "the future" which by definition is different
than now, and better.

Now, obviously, you can't maintain "progress", as it's called, forever. For
society to last it has to attain some sort of stable state (even if that
"state" is more of a dynamic "strange attractor", like the rise and fall of
empires.) On the individual level the psychology of being future-fixated runs
counter to the sanity of peace which implies contentment in the here-and-now.

But we do not want to forgo science, nor the obvious benefits that accrue to
industrial, scientific technology. (Rockets, computers, materials, medicine,
etc.) I don't imagine a world of navel-gazers in stasis.

SO, a Minimum Viable Civilization has to contain the core of our technical
know-how, it has to allow for continuation of scientific investigation, and it
has to look superficially like a combination of neolithic hunter-gatherers and
Jeffersonian agrarian republic (economically if not politically) together in a
stable mode: The farmers can't take new land without they leave the old to the
wilderness. And the wilderness is actually high-touch horticulture over much
of its area, although true wild lands would be set aside (for the spirits and
whatnot.)

You would still have your Large Hadron Collider but no plastic in the oceans.

The rest of this is an excerpt from a bit I wrote in 2013, in the context of a
"Future History" fictional projection. (I was very encouraged when I saw E. O.
Wilson's "Half Earth"!)

In the future the surface of the Earth has been divided into two kinds of
zones or areas: "Inside" and "Outside".

Inside: Artificial, Safe, Immortal

There is a single city but it's discontinuous, not connected. It's like
islands and archipelagos of built area embedded in a "sea" of wild land and
water. The city is ultra-tech, nano and beyond. People there do not age, or
age and rejuvenate as they please. All the transhumanist techno-utopian dreams
are come to fruition within the City. Barring accidents you live as long as
you want and it is Christmas every single day.

Outside: Real, Dangerous, Reproductive

The rest of the world is one giant Nature reserve. All of the oceans and the
great majority of the land masses are kept in a Natural state and evolution is
permitted to continue without interference from our human institutions within
the City. People live Outside too, in tribes and homesteads, and although
there is first aid and basic medicine and surgery, they voluntarily endure the
"slings and barbs of outrageous fortune". Transhuman modifications and forms
are not "worn" Outside. This is also where all new people are conceived,
gestated, and born. If you want to have a baby and raise a child you have to
go Outside.

This is Humanity's grand compromise with our technology. In order to maintain
a normative baseline, a "control group", for our wild forays into the
Transhuman realms Inside we have to permit our own natural evolution to
proceed Outside.

Graduation

I hadn't figured out what form it would take (it's an ongoing story idea I'm
still playing with) but there would be some sort of "intake" or "graduation"
process for bringing new humans into the City for the first time. I have no
idea, I'm just mentioning it. ^_^

~~~
carapace
This is from another old thing I wrote:

If you hang out with plants and help them then you are a _Grower_.

If you are making something with your hands that involves protons and neutrons
then you are an _Artisan_.

If you are making something that can be transmitted through photons and
electrons then you are a _Designer_.

If you are helping people to feel better then you are a _Healer_.

If you are helping people to grow then you are a _Teacher_.

I think that just leaves _Artist_ and _Scientist_? I'm going to say that both
of those roles are concomitant of the others to a greater or lesser degree per
ones own personal tastes and nature.

    
    
        Grower
        Artisan
        Designer
        Healer
        Teacher
        Artist
        Scientist 
    

Every other role will be eliminated or fulfilled by machinery. Go take out the
phone book, if you still have one. Flip though it and see what I mean, nearly
everybody in there is about to made obsolete by automation.

As for the structure of the economy I foresee three "levels" or "strata".

The first layer is made up of locally grown and consumed food and other
wholesome organic products. On the primary physical level we'll live quite
close to the way our "stone-age" ancestors did (and no, billions will not have
to perish to let it happen) only with nice houses.

That original organic economy will form the basis or substratum for the other
two layers.

There will be an "information" layer where most economic activity takes place
that involves people creating wealth in digital form. More than enough has
been said about that.

The last layer is relatively sparse and consists of whatever physical
transactions are needed to support the two other layers but that are not
strictly "of them", meaning non-purely-digital and not ecological or organic.
This involves things like extracting particular elements from the Earth for
specific experiments and projects.

~~~
mponw
I think this is a beautiful role playing game indeed :) Thanks for sharing, I
am inspired!

~~~
carapace
That's one of the nicest things anyone has ever said to me. Cheers!

------
dmix
I'm curious how much of an effect the forestry industry has on these mycology
networks as long as the trees get replanted. After coming across this quote:

> In Sweden, scientists studied a spruce that appeared to be about 500 years
> old. They were surprised to learn that it was growing from a root system
> that was 9,550 years old.

> In Switzerland, construction workers uncovered stumps of trees that didn’t
> look very old. Scientists examined them and discovered that they belonged to
> pines that lived 14,000 years ago. Analyzing the rings of their trunks, they
> learned that the pines that survived a climate that warmed 42°F, and then
> cooled about the same amount — in a period of just 30 years! This is the
> equivalent of our worst-case projections today.

------
daxfohl
Ever since reading the recent HN-highlighted article "Aliens in our midst" re
ctenophore brains, [https://aeon.co/essays/what-the-ctenophore-says-about-the-
ev...](https://aeon.co/essays/what-the-ctenophore-says-about-the-evolution-of-
intelligence), I've been wondering if something similar happens among plants.
This article shows definitely _something_. I'm interested to see how far it
goes.

------
dredmorbius
I'm starting to lean toward the notion that trees don't _have_ nervous
systems, but that forests _are_ nervous systems.

A complex, largely chemically-mediated, environmental-response mechanism.
Typically operating at rates far slower than those of animal neurology.

Trees don't have brains: forests _are_ brains.

------
bitwize
Insert Derrick Jensen quote about how the science of the dominant culture has
discovered that trees have souls and can talk only now, after it has nearly
ruined everything.

------
frogcoder
here is her ted talk

[https://www.ted.com/talks/suzanne_simard_how_trees_talk_to_e...](https://www.ted.com/talks/suzanne_simard_how_trees_talk_to_each_other)

