The secret language of trees - Camille Defrenne and Suzanne Simard
-
0:11 - 0:14Most of the forest lives in the
shadow of the giants -
0:14 - 0:16that make up the highest canopy.
-
0:16 - 0:17These are the oldest trees,
-
0:17 - 0:21with hundreds of children and
thousands of grandchildren. -
0:21 - 0:24They check in with their neighbors,
sharing food, supplies, -
0:24 - 0:27and wisdom gained over their long lives.
-
0:27 - 0:34They do all this rooted in place, unable
to speak, reach out, or move around. -
0:34 - 0:37The secret to their success lies
under the forest floor, -
0:37 - 0:41where vast root systems support the
towering trunks above. -
0:41 - 0:46Partnering with these roots are symbiotic
fungi called mycorrhizae. -
0:46 - 0:50These fungi have countless branching,
thread-like hyphae -
0:50 - 0:53that together make up the mycelium.
-
0:53 - 0:57The mycelium spreads across a much larger
area than the tree root system -
0:57 - 1:00and connect the roots of different
trees together. -
1:00 - 1:04These connections form
mycorrhizal networks. -
1:04 - 1:05Through mycorrhizal networks,
-
1:05 - 1:11fungi can pass resources and signaling
molecules between trees. -
1:11 - 1:14We know the oldest trees have the
largest mycorrhizal networks -
1:14 - 1:16with the most connections to other trees,
-
1:16 - 1:19but these connections are incredibly
complicated to trace. -
1:19 - 1:24That’s because there are about a hundred
species of mycorrhizal fungi– -
1:24 - 1:28and an individual tree might be colonized
by dozens of different fungal organisms, -
1:28 - 1:32each of which connects to a
unique set of other trees, -
1:32 - 1:36which in turn each have their own unique
set of fungal associations. -
1:36 - 1:39To get a sense of how substances flow
through this network, -
1:39 - 1:41let’s zoom in on sugars,
-
1:41 - 1:45as they travel from a mature tree to a
neighboring seedling. -
1:45 - 1:48Sugar’s journey starts high above
the ground, -
1:48 - 1:51in the leaves of the tallest trees
above the canopy. -
1:51 - 1:55The leaves use the ample sunlight up there
to create sugars through photosynthesis. -
1:55 - 1:58This essential fuel then travels
through the tree -
1:58 - 2:01to the base of the trunk in the thick sap.
-
2:01 - 2:04From there, sugar flows down to the roots.
-
2:04 - 2:07Mycorrhizal fungi encounter the
tips of the roots -
2:07 - 2:10and either surround or penetrate
the outer root cells, -
2:10 - 2:13depending on the type of fungi.
-
2:13 - 2:17Fungi cannot produce sugars, though they
need them for fuel just like trees do. -
2:17 - 2:18They can, however,
-
2:18 - 2:22collect nutrients from the soil much
more efficiently than tree roots— -
2:22 - 2:26and pass these nutrients into
the tree roots. -
2:26 - 2:27In general,
-
2:27 - 2:30substances flow from where they are more
abundant to where they are less abundant, -
2:30 - 2:32or from source to sink.
-
2:32 - 2:36That means that the sugars flow from the
tree roots into the fungal hyphae. -
2:36 - 2:38Once the sugars enter the fungus,
-
2:38 - 2:41they travel along the hyphae through
pores between cells -
2:41 - 2:44or through special hollow
transporter hyphae. -
2:44 - 2:47The fungus absorbs some of the sugars,
-
2:47 - 2:50but some travels on and enters
the roots of a neighboring tree, -
2:50 - 2:53a seedling that grows in the shade and
has less opportunity -
2:53 - 2:56to photosynthesize sugars.
-
2:56 - 3:00But why does fungus transport resources
from tree to tree? -
3:00 - 3:03This is one of the mysteries of the
mycorrhizal networks. -
3:03 - 3:07It makes sense for fungus to exchange soil
nutrients and sugar with a tree— -
3:07 - 3:09both parties benefit.
-
3:09 - 3:13The fungus likely benefits in less obvious
ways from being part of a network -
3:13 - 3:18between trees, but the exact ways
aren’t totally clear. -
3:18 - 3:20Maybe the fungus benefits from
having connections -
3:20 - 3:22with as many different trees as possible,
-
3:22 - 3:26and maximizes its connections by shuttling
molecules between trees. -
3:26 - 3:29Or maybe plants reduce their
contributions to fungi -
3:29 - 3:33if the fungi don’t facilitate exchanges
between trees. -
3:33 - 3:34Whatever the reasons,
-
3:34 - 3:39these fungi pass an incredible amount
of information between trees. -
3:39 - 3:43Through the mycorrhizae, trees can tell
when nutrients or signaling molecules -
3:43 - 3:46are coming from a member of their
own species or not. -
3:46 - 3:50They can even tell when information is
coming from a close relative -
3:50 - 3:52like a sibling or parent.
-
3:52 - 3:55Trees can also share information
about events like drought -
3:55 - 3:58or insect attacks through their
fungal networks, -
3:58 - 4:01causing their neighbors to increase
production of protective enzymes -
4:01 - 4:03in anticipation of threats.
-
4:03 - 4:08The forest’s health relies on these
intricate communications and exchanges. -
4:08 - 4:11With everything so deeply interconnected,
-
4:11 - 4:15what impacts one species is bound
to impact others.
- Title:
- The secret language of trees - Camille Defrenne and Suzanne Simard
- Speaker:
- Camille Defrenne and Suzanne Simard
- Description:
-
View full lesson: https://ed.ted.com/lessons/the-secret-language-of-trees-camille-defrenne-and-suzanne-simard
Most of the forest lives in the shadow of the giants that make up the highest canopy. These are the oldest trees, with hundreds of children and grandchildren. They check in with their neighbors, share food, supplies and wisdom gained over their lives, all while rooted in place. How do they do this? Camille Defrenne and Suzanne Simard explore the vast root system and intricate communication of trees.
Lesson by Camille Defrenne and Suzanne Simard, directed by Avi Ofer.
- Video Language:
- English
- Team:
closed TED
- Project:
- TED-Ed
- Duration:
- 04:18
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Elise Haadsma approved English subtitles for The secret language of trees | |
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Elise Haadsma accepted English subtitles for The secret language of trees | |
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lauren mcalpine edited English subtitles for The secret language of trees |