Frozen whitebark pines emerge from a melting glacier in the Yellowstone region. (Photo courtesy of Daniel Staehle, Montana State University)
Ice melting in the Rocky Mountains has revealed a perfectly preserved forest that had been frozen for thousands of years.
The Beartooth Plateau, at an altitude of over 10,000 feet (3,000 meters), is a barren, tundra-like landscape. However, it was not always like this: beneath the ice lies an ancient forest.
A cooling climate about 5,500 years ago quickly covered this white pine (Pinus albicaulis) forest in ice, preserving the trees almost pristine. Now, as ice patches frozen for centuries are melting due to climate change, scientists are uncovering clues about what this ancient landscape was like and how it was preserved. They detailed their findings Dec. 30, 2024, in the journal PNAS.
“Nobody had any idea that these patches of ice existed for thousands of years,” David McVety, an associate professor of earth sciences at Montana State University and a co-author of the study, told Live Science. “It looked completely different than it does today.”
This ancient forest of whitebark pines thrived for centuries at much higher altitudes than the same tree species found in the area today. This is because the global climate underwent a warm period between the end of the last ice age, about 10,000 years ago, and when these whitebark pines died more than 5,000 years ago.
On the edge of the glacial area on the Bear Tooth plateau there was a forest frozen in time.
This high-altitude forest was once a vibrant ecosystem that likely supported animals and the people who hunted them. From the same icy patch, Craig Lee, an associate professor at Montana State University and a co-author of the study, recovered a 10,000-year-old wooden shaft. The shaft was likely part of a spear used by people for hunting.
“We don’t realize how dynamic this alpine ecosystem was over time: people used it, animals used it,” Katie Whitlock, director of the paleoecology lab at Moscow State University and senior author of the study, told Live Science. “You go there now, and it’s amazing — it’s a very dramatic landscape — but it’s a little bit harsh.”
McVety suggested that the trees probably died because of a gradual cooling of the climate at the end of the warm period. Shortly after their death, a series of volcanic eruptions
Sourse: www.livescience.com
