• 3 days ago
Some of them attack trees, others fuse with them. And even if most of them cannot be seen by the naked eye, fungi are essential to the proper functioning of the forest.
Transcript
00:00We have three large groups of mushrooms in the forest,
00:02and now I'm going to take you to the mushroom forest,
00:05behind, in this wood, to convince you that these mushrooms are essential for the good functioning of the forest.
00:3199% of the mushrooms are microscopic filaments that colonize the soil or the dead branches.
00:37And at certain times of the year, when the conditions are full,
00:40in the fall in particular, when there is a lot of humidity,
00:43they form this sexual apparatus, where the formation of spores takes place.
01:00In fact, it is not a root that we have there, it is a mushroom root.
01:04And it is these little roots there, these millions of little roots,
01:07these hundreds of millions of little roots, that will absorb these nutrients.
01:11The tree pumps phenomenal quantities, tons of water every day,
01:15but it also needs considerable quantities of nutrients.
01:23This network of mushrooms, which we have here,
01:27this mycelium network can cover square kilometers.
01:30So if we try to calculate roughly,
01:33half of the mass of the forest is mushroom,
01:37but not the mushroom that we pick up in the fall.
01:39This network is an underground net that colonizes the entire litter,
01:43which is around us, and which connects the trees to each other.
01:57This dead tree is already badly degraded by the decomposing mushrooms.
02:02You will see, if I remove this part there, which is already terribly degraded,
02:07we see, we guess, a part, a whitish area there.
02:10In fact, it is the mushroom filament network that is consuming the tree.
02:16So this network, which looks a lot like cables,
02:21is mushroom, which is made up of microscopic filaments,
02:25but which are capable, which have the ability to assemble
02:29to form much more rigid structures.
02:32And thanks to these structures, it can go very far,
02:35explore all the parts of the tree and digest.
02:38It is thanks to these decomposing mushrooms
02:41that the cycle of nutrients in the forest will be ensured, looped.
02:45It recycles carbon, but it also recycles all the other nutrients
02:49of dead trees and plant debris.
02:52And that's what's going to make the soil rich and fertile.
03:04We probably have a tree that was attacked
03:07by the third group of mushrooms that live in the forest,
03:11parasitic, pathogenic mushrooms, which attack living plants,
03:15which will colonize them and eat them on foot, devour them.
03:19I call them the truants.
03:21And we, the foresters, we don't like them very much
03:24because they cause significant damage in the forests.
03:34Mushrooms could help us in at least three ways
03:37to fight climate change.
03:39The first is to select symbiotic mushroom species
03:42that help trees fight drought.
03:45The second way is to do everything to promote the development
03:49and growth of this mushroom network in the soil
03:52because 50% of the carbon is stored in this mushroom network
03:56in the forest soil.
03:58And the third way is to promote the interaction
04:01between symbiotic mushrooms and trees
04:04because it is these symbiotic mushrooms that stimulate
04:07the growth of trees.
04:09And by stimulating the growth of trees,
04:12they make wood and wood stores carbon.