On savait déjà qu'un cataclysme majeur survenu à la fin du Permien (il y a environ 250 millions d'années) avait causé des extinctions massives: 95% des espèces marines et 70% des animaux terrestres furent complètement anéantis.
Une récente étude semble indiquer que les forêts elles-mêmes furent détruites:
Massive volcanic eruptions wiped out the world's forests about 250 million years ago, leaving the planet teeming with wood-eating fungi, according to a new study. The finding confirms that even hardy trees didn't survive the Permian mass extinction, one of the most devastating losses of life Earth has ever known. (...) But the new study confirms that vegetation also suffered heavy casualties. (...) And trees remained a rarity for the next four million years. But fungi, which could cope with the newly acidic world, survived.
L'étude est accompagnée d'un avertissement pour l'avenir:
On a global scale, human activity is altering the balance of gases in Earth's atmosphere "faster than anything we see in the geological record," Sephton added. In addition, the drop in species diversity today mirrors the early stages of the Permian event. "This is mankind's great unnatural experiment," Sephton said, "and we just don't know how it is going to end."
Photo trouvée ici.
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