Bald cypress trees established themselves in the swamps of what is now the northern Gulf of Mexico during the last Ice Age, before an unknown cataclysmic event buried ancient forests. Today, divers scavenge trees from sediments under Gulf waters and find them as fragrant as when they were buried in the Pleistocene era.
In 2004, Hurricane Ivan swept through the region and exposed the ancient forest, according to researchers at Louisiana State University (LSU). They dived to find the tree stumps at depths of about 60 feet, eight miles off the Alabama coast.
“We were surprised to find this cypress wood intact, as the wood normally breaks down in the ocean from seaworms and bacteria,” said Kristine DeLong, marine geologist and paleoclimatologist, associate professor in the department of geography. and anthropology of the LSU.
Her grandfather had felled cypress trees in Florida and she reported that the excavated wood “smells like freshly cut cypress”.
Bald cypress (Taxodium distichum) is established throughout the Southeastern United States and was highly prized in the 19th century for its resistance to decay, water rot, and insects. The species is now protected.
DeLong and his team began diving at the site in 2013, when they collected the first cypress specimens for analysis. They found them too old for radiocarbon dating, but through other methods they established that the forest appeared at the start of the last Ice Age, 42 to 74,000 years ago.
The divers then collected sediment cores in the area. They found sand and seashells in the top layers but also organic peat with roots and leaves towards the bottom of the tubes.
“As a marine geologist, we don’t see this type of sediment,” DeLong said. “What was interesting was finding the seeds of St. John’s Wort, Button Bush and Rose Mallow, which are native plants that can be found on earth today.”
The team has collaborated with experts in trees and terrestrial plants, but remain perplexed about the survival of the specimens, even if the low oxygen content of the swamp waters could have stopped their decomposition.