VANCOUVER -- Climate change is expected to drive lodgepole pine, the backbone of the central Interior forest industry, from most of its range in B.C. by 2080, says a study by researchers at the University of B.C. and Oregon State University.
The study, to be published in the journal Climate Change, measures how trees respond physiologically to changes in their environment, resulting in precise forecasts for researchers Nicolas Coops at UBC and Richard Waring at OSU. Although lodgepole pine will be mostly gone by 2080, as early as 2020, its habitat will begin shrinking. It is expected to move northward into the Yukon.
The researchers used NASA satellite maps to trace changes in tree physiology, using sophisticated techniques that, for example, can measure the impact of drought by changes in the reflectivity of a tree’s needles as seen from space. It is the first time such precise modeling has been undertaken to measure tree response to climate change.
The satellite images show climate-change induced drought is already affecting lodgepole pine. Coops said drought stresses the tree, making them more susceptible to disease and pests like the pine beetle.
The researchers say that lodgepole pine will be gone from almost all of the Pacific Northwest and wiped out in 83 per cent of its range in B.C. by 2080. That’s within the lifetime of seedlings now being planted in the wake of the mountain pine beetle epidemic.
“Even though lodgepole pine is a hardy species, it’s very susceptible to climate change, so it is going to be pushed out of the space where it grows very well,” Coops, a professor at the UBC Faculty of Forestry, said in an interview.
New species that are more drought tolerant and prefer warmer weather will move in, Coops said. The forest will also be more open because of increased forest fire activity. Ponderosa pine, Douglas fir and larch will replace pine, he said, but they will likely be less productive than the current pine-dominated forest.
“This is a bit of a problem because we keep planting lodgepole pine as our species after harvesting. But we are planting it in places where we know, over the next hundred years, the climate is going to be less and less suitable for them.”
The scientists based their modeling on a scenario developed by the Intergovernmental Panel on Climate Change that shows a three-to- five degree Centigrade temperature hike by 2080 if carbon emissions are not controlled and if the population continues to expand. It’s a “business as usual” scenario, Coops said.
B.C. Chief Forester Jim Snettsinger said in an interview that the new methods used by the researchers have produced results “a little more drastic” than other studies up to this point.
Based on existing research, he said it is well known that climate change will affect the province’s forests.
“Where it’s tough now, it’s likely to get tougher as the climate gets drier and warmer and in some of the areas where it is colder, as it warms up, it might be more favourable,” Snettsinger said.
The ministry of forests is conducting both long-term and short-term experiments to determine which species will survive in a warmer future.
Already larch, one of the species the study suggests will do better, is being planted in former pine stands in the Prince George region, Snettsinger said. Up to 10 per cent of a site can now be planted in larch, a species that turns golden in the fall and loses its needles over winter, after Snettsinger approved amendments to seed transfer policies last June.
He also said B.C. is taking part in a much larger experiment, called assisted migration adaptation trial, where seedlings from 15 different species that grow in B.C. are being planted in 48 different sites in this province, the Yukon and the American Pacific Northwest.
“This is long-term research but we will be able to watch these trees, measure them at various intervals to see how they have grown. We will also get some early results: the ones that die right away give you some information. The ones that do successfully establish themselves, we can measure.”
Where it’s tough now, it’s likely to get tougher as the climate gets drier and warmer and in some of the areas where it is colder, as it warms up, it might be more favourable.
“What this really means is you’ve got to have some research going on that models what you think is going to happen, you’ve got to have feedback loops to find out exactly what is going on — and that’s what our assisted migration adaptation trial will do — and in the meantime you have to allow for some changes in your seed use to make sure you don’t wait 20 or 30 years for something to happen,” Snettsinger said.
ghamilton@vancouversun.com