Study suggests Alaskan tree refuge existed

August 1, 2006

U.S. scientists say they've found strong evidence an Alaskan tree refuge existed during the last glacial period, 17,000 to 25,000 years ago.

University of Illinois researchers said a genetic analysis of living spruce trees suggests that trees cannot migrate in response to climate change as quickly as some scientists have thought.

"One view is that trees were restricted to areas south of the continental ice sheets covering North America, and then migrated extremely rapidly as the climate grew warmer," said Feng Sheng Hu, an ecologist at Illinois and corresponding author of the paper. "The other view is that there was a refuge in the ice-free areas north of the ice sheets, and spruce trees expanded within those areas as the climate warmed.

"It now seems clear that a glacial refuge existed, and the trees advanced from at least two directions," he said, noting the data also suggest it is likely the migration rate was lower than previously thought.

The research appears in the early online edition of the Proceedings of the National Academy of Sciences in advance of publication.

Copyright 2006 by United Press International

Explore further: Global warming and coral bleaching in the Great Barrier Reef

Related Stories

What does it mean to be human?

March 7, 2017

The Rock of Gibraltar appears out of the plane window as an immense limestone monolith sharply rearing up from the base of Spain into the Mediterranean. One of the ancient Pillars of Hercules, it marked the end of the Earth ...

Forest 'islands' offer refuge to wintering birds

February 7, 2017

The polar vortex of 2013 and 2014 brought the coldest winter many parts of the Midwest had experienced in decades. In Dane County, Wisconsin, it was the coldest it had been in 35 years.

Recommended for you

NASA discovers a new mode of ice loss in Greenland

May 26, 2017

A new NASA study finds that during Greenland's hottest summers on record, 2010 and 2012, the ice in Rink Glacier on the island's west coast didn't just melt faster than usual, it slid through the glacier's interior in a gigantic ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.