Researchers discover 30-million-year-old hidden forest on 'treeless island'

Spread over an area of 4,700 miles, the Falkland Islands boast of tranquility that is interrupted only by the melody of birds basking in the sun, golden bushes scattered along its white-sand beaches, and sparkling water bodies. This picturesque beauty thrives even though the landscape remains treeless due to its acidic grass and the South Atlantic’s cool climate. So, when Dr. Zoë Thomas heard that there were huge tree trunks buried in the soil of the Falkland Islands, she was naturally curious.

In a study published in the journal called Antarctic Science, she and her team of researchers revealed that the rugged Falklands were once home to a lush rainforest. Back in 2020, Thomas was out for a field investigation for a project in the Falklands when a fellow researcher sent her word that a tuft of tree trunks had been unearthed at the Tussac House, a living facility for the elderly. The building stands at the foreshore of Stanley Harbour, the capital of the eastern Falklands islands. “We report the discovery of a buried lignitic deposit during excavations for the foundations of the Tussac House,” the researchers wrote in the study.

“These were so well preserved, they looked like they'd been buried the day before, but they were in fact extremely old,” Thomas, who is a physical geography expert at the University of Southampton, described in a statement. She added that this unexpected discovery immediately piqued their interest because the Falklands are known as a treeless and barren place.

Lying 335 miles east of the coast of South America, the volcanic Falklands Islands were first formed during the breakup of the supercontinent Gondwana. It took shape when the waters of the Atlantic Ocean broke up and gave rise to the South Atlantic tectonic plate, where the Falklands Plateau emerged. Given the influence of cool Atlantic waters, the climate here remains cool with low precipitation throughout the year, in which acidic white grass and tussac grass make it impossible for timber-sized trees to grow from the soil. Hence, finding the pile of wooden tree logs on the islands was quite unusual.

After receiving the information, the team reached the Tussac House site and drilled geotechnical boreholes to unearth peats underlaid by sediments that comprised “thick blue-grey clay overlaying the lignitic organic deposit.” The wooden fragments and deposits were collected from the site and samples were sent to Australia for laboratory testing at the University of New South Wales. This excavation was carried out with the help of the South Atlantic Environmental Research Institute (SAERI) in Port Stanley.

In the laboratory, the tree samples were investigated using electron microscopes. The fragments however proved too old to be tested by radiocarbon dating which can date a relic up to only 50,000 years old. So, the team turned to microscopic pollen and spores to unleash the age of these buried trees. Their work revealed that the fossilized tree trunks and branches discovered were an estimated 15 million and 30 million years old.

“The age limits for the study site were estimated based on age ranges of pollen species from Patagonian rocks and comparisons with similarly aged floras from southern Patagonia and Antarctica,” Michael Donovan, paleobotany collections manager at Chicago’s Field Museum, told CNN. Similarities with Patagonian forests suggested that the Falklands had a warmer and wetter climate millions of years ago.

“Most of the fossil pollen and spores preserved in the Tussac House forest bed closely resemble pollen and spores produced by plants in the modern floras of South America and other landmasses in the Southern Hemisphere,” researchers noted about the antiquity of the Tussac House forest bed, and added, “This study affirms that the South Atlantic region hosted diverse rainforests during the mid to late Cenozoic period.” They concluded that all fossil pollen and spores recovered from the site represent the same cool temperate rainforest scrub that burst through the earth of the Falklands millions of years ago.