Svalbard, Norway is renowned for its harsh Arctic climate, glaciers and polar bears. But the region hasn’t always been like this. UK scientists have discovered ancient fossilised tropical forests preserved in the Earth’s surface.
Identified and researched by Chris Berry of Cardiff University, the forests actually grew near the equator at the end of the Devonian time period but preserved tree stumps have, in fact, been found far away on the Norwegian archipelago of Svalbard, located within the Arctic Circle. So how has this land of tropical vegetation managed to migrate several thousand miles northwards? Continental drift is the answer here, whereby tectonic plates are moved by convection currents powered by the rising and cooling of magma in the Earth’s mantle over millions of years. This means that the islands of Svalbard were indeed located on the equator around 380 million years ago, which is how old the forest has been dated to be by Professor John Marshall from the University of Southampton. That’s 20 million years older than previous estimates!
“The islands of Svalbard were indeed located on the equator around 380 million years ago, which is how old the forest has been dated”
These forests are thought to explain the dramatic drop in atmospheric carbon dioxide levels that occurred 420-360 million years ago, otherwise known as the global cooling event, which inevitably resulted in the currently much colder climate of the region. This can be explained by the forests using the chemical process of photosynthesis to build tissues by extracting carbon dioxide from the atmosphere in order to produce oxygen and glucose using sunlight and chlorophyll in the tree’s leaves. Scientifically categorised as lycopsids, these types of trees are thought to have grown to a height of 13 feet and reproduced with spores so tended to grow within close proximity to each other. This means that these forests would have been densely populated, therefore, absorbing higher volumes of carbon dioxide than smaller plant life that previously grew on the planet.
“Svalbard is known for its Seed Vault, which was built to refrigerate and preserve a variety of seed samples collected from around the world.”
Research suggests that atmospheric carbon dioxide decreased a staggering fifteen times the amount it is today, to measure close to the current level. Not only does this indicate just how unbearably hot this greenhouse gas would have made global temperatures millions of years ago, it also helps scientists to establish what the vegetation and landscapes were like on the equator 380 million years before, just as the first larger trees were beginning to appear on earth.
Nowadays, Svalbard is famously known for its Seed Vault, which was built to refrigerate and preserve a variety of seed samples collected from around the world. “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,” Chris Berry said.
The new findings have been published in the journal Geology.
Last modified: 14th December 2015