Researchers rediscovered a 22-million-year-old mangrove forest that was swept away by a massive volcanic eruption. The forest that once thrived with huge trees and lush green grasses on an island in the Panama Canal fell prey to natural disasters that triggered complete destruction.
The rediscovery was made by the scientists at the Smithsonian Tropical Research Institute, who found the fossilised remains of trees on the Barro Colorado Island. Not just one or a dozen, but a total of 112 preserved fossilised pieces of wood were unearthed.
Scientists rediscover long-lost forest
The fossils found indicated that some huge volcanic eruption triggered a lahar that eventually swept away the entire forest land. A lahar is a violent flow of water with mud, ash, and rocks. When it flows it almost flows like wet concrete at lighting speeds that can instantly cover an area into a whirlwind.
A lahar leaves plants and animals no opportunity to rot or decompose and instantly destroys the entire land. What is more destructive is that lahar comes with silica-rich waters that seep deep into living matter and expunge their tissues, which results in well-preserved fossils locked in a moment in time.
How did such a huge mangrove forest originate in ancient times?
As per the scientists, this old mangrove forest would have originated in the early Miocene Epoch, which existed about 23 million years ago. The great land masses of South America and the Caribbean plate collided with each other forming the landscape of Panama and the rest of Central America.
This was when the hill that would eventually become Barro Colorado Island rose from the ocean. Around its edges grew a mangrove forest, whose trees rose as high as 130 feet into the air, wrote the study’s authors.
Sediment samples show that the forest grew in the brackish zone where salty and fresh waters meet, ideal conditions for mangroves. But the brackish water wasn’t the only thing that made the conditions ideal for a massive mangrove forest.
Atmospheric carbon dioxide concentrations were much higher during the Miocene than now – over 500 parts per million (ppm) as compared to about 419 ppm today.
Since trees consume carbon dioxide to grow, the scientists concluded that these ancient species would have been able to reach heights much greater than current-day mangrove trees.
These ancient remains revealed a lot about the forgone forest but the study is still in its incipient stage. The findings of the study will be published in the March 2024 issue of the Palaeogeography, Palaeoclimatology, Palaeoecology journal.
(With inputs from agencies)
