Building a better forest

Mark Hendricks, Contributor Ω

Guest lecturer Sally Aitken from UBC spoke to TRU students about how modern science is helping our forests adapt to climate change. - Photo by Mark Hendricks

Guest lecturer Sally Aitken from UBC spoke to TRU students about how modern science is helping our forests adapt to climate change. – Photo by Mark Hendricks

University of B.C. forest science professor Sally Aitken’s presentation Can genetics help climate-proof our forests? was titled to inspire some controversy. Could the answer to the Feb. 7 environmental science seminar presentation be that simple? It wasn’t. Aitken’s presentation would have been much shorter if that had been the only question.

“I could have just stood here and said ‘no’ and you could have gone home,” Aitken said to the audience of 40. “There is no gene for climate change.”

The speech continued to explain how genetics helps determine what makes certain trees within a species thrive in certain climates.

Also discussed was assisted population migration, the act of moving trees to a new climate faster than they would naturally move due to the spread of seeds and pollen.

Genetics has allowed scientists to identify which trees within a species are already adapted to warmer or colder climates.

This is possible due to modern advances in science that are allowing us to look at single nucleotide polymorphisms, which is the change caused within a single building block of DNA, called a nucleotide.

The reason this has become a necessity is that human actions have caused climates to change faster than trees naturally spread. Climates are shifting 70 times faster than the ranges of the trees. Based on pollen records, the range of trees shift by a maximum of 100 metres a year. Climates are shifting at a rate of 7,000 metres a year.

“We’ve got the wrong trees in the wrong place,” Aitken said. “All of a sudden local is no longer best.”

Aitken does not believe in moving trees outside of their natural range, but she said moving trees within their natural range to accommodate changing temperatures could be beneficial.

“It appears as if there’s potential there, that is not the same as saying should we do it,” Aitken said. “The question of ‘should we?’ is a societal question, the question of ‘can we?’ is a biological question.”

Aitken admits there are risks involved in assisted population migration, but believes it is better than the alternative.

“We can’t just look at the risks of what we do,” Aitken said. “We’ve got to look at the risks of not doing as well.”

The risks of action as identified by Aitken are altered ecosystems, potential invasive species and adaptations to non-climactic factors.

The risks of not doing anything include low forest productivity, loss of ecosystem services and slower adaptive responses to changing climates.

Assisted population migration is a temporary solution to an on-going and external problem — climate change. Unless the environment becomes more stable, the need for assisted population migration will arise again.

“We have to put the brakes on climate change, we have to put the brakes on greenhouse gases,” Aitken said. “We appear as a country to be doing absolutely nothing on that front.”