Canadian tundra was once covered in thick forest

Dec. 13 (UPI) — Today, Canada’s Ellesmere and Axel Heiberg islands are treeless. The tundra’s grasses and shrubs rise no more than a foot or so off the oft-frozen ground.

New research suggests the island weren’t always quite so barren. Analysis of some 5,000 fossil samples from the Canadian Arctic — the largest such survey — showed Canada’s northernmost islands were once covered in rich temperate forest.

“It’s very surprising how similar these ancient polar forests were to some of our modern forests,” paleobotanist Christopher West, who recently received earned his doctorate at the University of Saskatchewan, said in a news release. “I identified fossil plants related to many modern temperate trees: birch, alder, elms — even plants belonging to the grape family. Some of the fossils are related to trees now found only in East Asia.”

West and his colleagues described the results of their fossil survey this week in the journal Palaeontographica B. According to the study’s authors, the research can help climate scientists better understand the influence of rising temperature on forest ecosystems.

“If we are able to understand how ecosystems long ago responded to global warming, we may be able to better predict how our own modern ecosystems will respond to our own rapidly warming climate,” West said. “This research will also help climate modelers as they use data from the past to better understand our own climate.”

West conducted much of the research while working as a doctoral student, one of many who have assisted Jim Basinger, professor of geology at the University of Saskatchewan.

“This research is the cumulative effort of almost 40 years of work on fossil plants of the Canadian North undertaken by me and my students, including 20 field seasons on Ellesmere and Axel Heiberg islands,” Basinger said.

The unprecedented survey of Arctic plant fossils helped scientists confirm the presence of 83 different plant types in Canada’s high Arctic latitudes during the early Eocene, some 56 million years ago.

During the early Eocene, Earth was even warmer than it is today. For much of the year, the Ellesmere and Axel Heiberg islands would have endured long periods of darkness, the sun hidden behind the horizon. Buoyed by warmth, the forests grew anyway.

“We won’t see a return to a forested polar region in our lifetimes, but it is important to remember that we as humans have become agents of climate change, and that our warming climate will have potentially dramatic effects on our modern ecosystems,” West said.





Source link