It may be hard to visualize, or even believe, but a forest used to thrive in the expanse that is now Antarctica. Recently, however, researchers discovered the fossilized remains of some of the trees that made up this ancient forest.
Antarctica was once covered in forests.
Summer in Antarctica isn’t a lot like summer anywhere else. Summer elsewhere may have a lot of sunlight, but summer in Antarctica means sunlight for 24 hours. Of course, there’s also the subzero temperatures and cruel winds. Summer in Antarctica may seem daunting, but a team of researchers had a job to do.
These researchers spent November 2016 to January 2017 trekking through snowy slopes, braving freezing winds, and examining the sedimentary rocks of Transantarctic Mountain. By the end of their search, the researchers found a total of 13 fossilized fragments from trees as old as 260 million years, which meant that the trees were alive around the time of the greatest mass extinction event in history.
A 260-million-year-old fossil of a prehistoric tree [Photo by Erik Gulbranson]
Around 252 million years ago, the Permian Extinction event occurred, resulting in up to 96% of the species on the planet going extinct. Before the Permian Extinction took place, however, a single type of tree populated the forests in the south pole. These trees belonged to the Glossopteris genus, and they were able to grow to 20 to 40 meters tall. At the time, Antarctica was much warmer than it is now.
"Antarctica preserves an ecologic history of polar biomes that ranges for about 400 million years, which is basically the entirety of plant evolution," said paleoecologist Erik Gulbranson, one of the researchers. He also stated that the forests didn’t actually disappear after the Permian Extinction. However, they did change. "What we're trying to research is what exactly caused those transitions to occur, and that's what we don't know very well.”
Though the trees inhabited Antarctica back when it was warmer, they still had to be quite resilient. They would have had to live through months of darkness, and experts think that these trees may have gone dormant in the winter. If this is true, then the fossils may provide answers as to how the trees were able to hibernate.
Fossilized Glossopteris leaves from Australia, which are the same as the ones found in Antarctica [Photo by Wild Horizons/UIG via Getty Images]
According to the researchers, the large prehistoric trees were able to transition easily and quickly from one season to another. They could go from summers in which the sun never sets, to winters in which the sun never rises. Gulbranson says that they don’t fully understand how the trees were able to cope with these transitions, “just that they did”.
Scientists also aren’t sure what caused the Permian Extinction. Theories range from an asteroid impact to volcanic activity that released massive amounts of greenhouse gases, leading the planet to get warmer in a short period of time. Examining the fossils, however, may give researchers answers or at least clues to these questions.
The trees had been preserved in volcanic ash down to their cellular level, which is likely to make it possible for researchers to find the answers they’re looking for. The findings of the rest of their research can also give us a preview into the effects of rapid climate change, especially if volcanic activity did indeed cause the Permian Extinction.
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