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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 thousands of
grandchildren they check in with their
neighbors sharing food supplies and
wisdom gained over their long lives they
do all this rooted in place unable to
speak reach out or move around the
secret to their success lies under the
forest floor where vast root systems
support the towering trunks above
partnering with these roots a symbiotic
fungi called mycorrhizae these fungi
have countless branching thread-like
HiFi that together make up the mycelium
the mycelium spreads across a much
larger area than the tree root system
and connects the roots of different
trees together these connections form
mycorrhizal networks through mycorrhizal
networks fungi can pass resources and
signaling molecules between trees we
know the oldest trees have the largest
micro eyes or networks with the most
connections to other trees
but these connections are incredibly
complicated to trace that's because
there are about a hundred species of
micro fungi and an individual tree might
be colonized by dozens of different
fungal organisms each of which connects
to a unique set of other trees which in
turn each have their own unique set of
fungal associations to get a sense of
how substances flow through this network
let's zoom in on sugars as they travel
from a mature tree to a neighboring
seedling sugars journey starts high
above the ground in the leaves of the
tallest trees above the canopy the
leaves use the ample sunlight up there
to create sugars through photosynthesis
this essential fuel then travels through
the tree to the base of the trunk in the
thick sap from their sugar flows down to
the roots mycorrhizal fungi encounter
the tips of the roots and either
surround or penetrate the outer root
cells depending on the type of fungi
fungi cannot produce sugars though they
need them for fuel just like trees do
they can however collect nutrients from
the soil much more efficiently than tree
roots and pass these nutrients into the
tree roots in general substances flow
from where they are more abundant to
where they are less abundant or from
source to sink that means that the
sugars flow from the tree roots into the
fungal hyphae once the sugars enter the
fungus they travel along the HiFi
through pores between cells or through
special hollow transporter HiFi the
fungus absorbs some of the sugars but
some travels on and enters the roots of
a neighboring tree a seedling that grows
in the shade and has less opportunity to
photosynthesize sugars but why does
fungus transport resources from tree to
tree this is one of the mysteries of the
micro eyes'll networks it makes sense
for fungus to exchange soil nutrients
and sugar with the tree both parties
benefit the fungus likely benefits in
less obvious ways from being part of a
network between trees the exact ways
aren't totally clear
maybe the fungus benefits from having
connections with as many different trees
as possible and maximize its connections
by shuttling molecules between trees or
maybe plants reduce their contributions
to fungi if the fungi don't facilitate
exchanges between trees whatever the
reasons these fungi pass an incredible
amount of information between trees
through the mycorrhizae trees can tell
when nutrients or signaling molecules
are coming from a member of their own
species or not they can even tell when
information is coming from a close
relative like a sibling or parent trees
can also share information about events
like droughts or insect attacks through
their fungal networks causing their
neighbors to increase production of
protective enzymes in anticipation of
threats
the forest health relies on these
intricate communications and exchanges
with everything so deeply interconnected
what impacts one species is bound to
impact others so trees can sound the
alarm during an emergency but how
exactly do they defend themselves check
out this video for the mind-boggling
answer
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