Mummified Forest Shows Effect of Changing Climate
Posted by Kelly Greig
on Monday, January 17, 2011
Photo: Joel Barker.
It all started with a log. Joel Barker, an earth scientist from Ohio State University, was researching carbon dioxide emissions on Ellesmere Island, Nunavut, when he was told about an odd log sticking out of the snow. Since trees only grow sparsely and to a few feet high on the tundra, it was definitely out of place.
"I knew that was a rare thing and I was interested in seeing it," Barker tells CG, "I knew there was a possibility of forests up there in the past. When they told me they found logs I suspected that’s what we were dealing with."
Barker’s hunch was right. It turned out to be the discovery of Canada’s most northerly mummified forest. Now, just two years later, we're beginning to discover what this forest can tell us about our future.
What is mummified wood?
Mummified wood is created when trees are totally cut off from oxygen and sunlight. In this case, the researchers suspect that a landslide buried the forest, thereby preserving it. "It’s just like any wood you’d find out there today — it still burns," explains Barker.
The main difference between this and petrified wood is the effect of water perforation leaving dissolved minerals behind. In petrified wood, over time these minerals harden and transform the wood into rock.
"Here we can do all these analysis on it because it’s not rock, it’s wood," says Barker. "And as a result, we can get an idea of what was happening in the ecosystem."
History repeats itself
Barker’s research now consists of determining how the vegetation was affected by temperature. "We’re looking at stable isotopes in carbon and oxygen from individual trees to get an idea of how the water, temperature and global carbon levels were changing," he says. "By looking at the physical tree rings we’ll get an idea of how the trees were responding."
The forest existed during a cooling period around two to eight million years ago. A low diversity of plants and only five different types of trees indicate that this is was already a forest that was being affected by the change. "We interpret this as a site where the forest was just on the edge of collapsing completely," says Barker. "If you want to examine the effects of a changing climate on an eco-system, you want to find a site like this — one that’s just on the edge and will respond very dramatically to just subtle changes in climate."
This ancient forest could give us clues about the effects on vegetation if the current warming trend continues, explains Barker. "We’re answering a question about climate change and it doesn’t matter if it’s cooling or warming it’s about the ecosystem’s response to any change."