A new discovery made in the Svalbard archipelago has revealed that prehistoric Norway was a year-round sauna—and may have been partly responsible for one of the most radical shifts in the Earth’s climate within the past 400 million years.
As researchers from Cardiff University discovered, this part of Norway contains swaths of ancient fossil forests. But the trees found in Svalbard—which is situated in the Arctic Ocean—are not pine trees, but are actually the remains of tropical forests. According to their paper in Geology, these fossils have now been dated to 380 million years ago.
“Tropical” come as a bit of a surprise, but we can thank continental drift for that: 380 million years ago, during the late Devonian period, what would become Norway was situated right around the equator, allowing lush flora to take root. The area was dominated by lycopod trees, which could reach heights of about 12 feet.
And this newly-found flora may help explain an ancient mystery.
“During the Devonian Period, it is widely believed that there was a huge drop in the level of carbon dioxide in the atmosphere, from 15 times the present amount to something approaching current levels,” explained co-author Chris Berry, of Cardiff University’s School of Earth and Ocean Science, in a statement.
Why’d this change occur?
Of course, no one knew why this change occurred—but many guess it had to do with a sudden increase in plant size.
“The evolution of tree-sized vegetation is the most likely cause of this dramatic drop in carbon dioxide because the plants were absorbing carbon dioxide through photosynthesis to build their tissues, and also through the process of forming soils,” said Berry.
As carbon dioxide levels plummeted, the temperatures of the Earth dropped too, to levels close to what we have today. And plants at the equator probably contributed the most, thanks to the high temperatures and rainfall levels of the region—plants like those fossilized in Svalbard. These fossils now lend weight to the idea that an evolution in plant size changed the atmosphere.
“These fossil forests shows us what the vegetation and landscape were like on the equator 380 million years ago, as the first trees were beginning to appear on the Earth,” said Berry.
Interestingly, Svalbard—the keeper of these ancient tree remains—also hosts the Global Seed Vault. The Vault is a secure, underground, frozen seed bank, meant to provide a safety net in case a global crises leads to a sudden loss of plant diversity.
“It’s amazing that we’ve uncovered one of the very first forests in the very place that is now being used to preserve the Earth’s plant diversity,” said Berry.
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Feature Image: Dr. Chris Berry, Cardiff University
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