How British Columbia Is Moving its Trees
And why other provinces have yet to follow suit.
Image: Richard Droker/Flickr
The Western Larch can live for hundreds of years and grow to over 200 feet, but the oldest Larch trees in northern British Columbia's Bulkley Valley are only about four feet tall. In fact, the nearest full grown Western Larch is nearly 900 kilometers south by the US border, which has been the Larch's natural range for thousands of years. These are the first trees of their kind to be planted so far north.
If the disastrous history of invasive species has taught us anything, it's that it's often difficult to predict the consequences of such a change. Ecologists and conservationists generally caution against moving a species outside of the areas they naturally live—a process known as assisted migration—and governments generally agree with this take. Across North America there are strict prohibitions against the large scale movement of living populations.
But for the past seven years the province of BC has allowed millions of trees to be planted toward the northernmost reaches of their natural range and beyond. The government is working with scientists who predict that our climate is changing so quickly that, 50 years from now, when the trees are fully grown, the conditions in the trees' new homes will actually be more like their old ones.
"It restores the tree to the environment for which they are best suited," said Greg O'Neill, an adaptation and climate change scientist with the BC government, who helped design and implement the province's assisted migration program. But while BC scientists think that they've acted just in time to prepare their forests for the future, no other province appears ready to adopt assisted migration as a strategy anytime soon.
Many trees are what ecologists call foundational species—organisms whose removal would cause enormous disruption in the ecosystem. Trees are a sort of infrastructure for forests; they bind the soil, retain water, and provide food and shelter. Just like the infrastructure unpinning cities, it takes years to establish a tree population, and they are virtually impossible to move.
And yet, because BC's northern regions are warming at nearly twice the average rate, much of the province's 55 million hectares of forest may find that their homes have moved north without them. A 2006 paper from the University of British Columbia applied a climate based model to forest ecosystems and showed that some species ranges could shift by up to 100 kilometers each decade.
It's difficult to overstate how deeply rooted the aversion to moving nature is for many biologists
Rules in BC require that, as trees are cut down, planters use seeds from the same area to re-plant, preserving the genetic character of the forest. O'Neill and his colleagues produced a forestry report in 2008 that drew on the projected range expansions due to climate change, and their own extensive experiments testing various tree species in different climates. They suggested that the province instead expand the distance seeds could be moved uphill, to track with global warming. Later that year the Chief Forester's Standards for Seed Use were changed for the majority of BC's commercial tree species to reflect the suggestions in the report.
According to O'Neill, "these were the first policy changes that addressed climate change in forestry."
Then, in 2010 the standards were changed again, to allow Western Larch to be planted hundreds of kilometres away from its current range. "That had been a long-standing paradigm that no-one dared transgress," said O'Neill. One ecologist had even called BC's migration plans "a little scary."
It's difficult to overstate how deeply rooted the aversion to moving nature is for many biologists. In 2009 assisted migration was called "planned invasion" in a report that listed our really awful, truly just stupendously bad track record with species that unexpectedly turn invasive.
Climate change, though, has a way of changing how people think about risk, and the need to adapt is often framed in urgent terms. But a 2015 report from McGill University found that while the 117 nations participating in the United Nations Framework Convention on Climate Change have reported over 4,000 adaptation initiatives underway, from infrastructure and technology to flood warning systems, progress has largely consisted of planning and groundwork. "Progress on actual adaptation interventions […] is limited," it concluded.
There simply isn't much happening yet, despite the urgency. Some of the proposed plans, like Rotterdam's floating dome neighbourhoods, have a wonderful sort of Jetsons appeal—life in an inhospitable environment which proceeds largely unchanged, supported on platforms of wondrous technology. But BC's assisted migration program isn't like that at all. It involves risk, and huge changes to the natural world. Unlike most of the technology-reliant solutions though, it's ready to work now.
And while other provinces have taken note of what BC has been doing for the past five years, that's about all they've done.
A representative for the Alberta government said that current rules allow for a limited transfer of seeds to higher latitudes and elevations, meaning that in some cases trees can be moved to the northern edge of where they currently grow. Andreas Hamann, a biologist at the University of Alberta, says the province has been receptive to further climate policy changes, but hasn't yet committed to a systematic approach like BC's.
"I think we're as ready as BC has ever been. As far as research goes, the science is solved," said Hamann, who worked on some of the original research that led to BC's assisted migration policy, and is confident it would work elsewhere.
A statement sent by Andre Rainville at the Ministère des Forêts, de la Faune et des Parcs in Quebec—home to Canada's next-largest forestry industry after BC—said that their guidelines work on a case by case basis, some of which are based on climate models. They are currently working on an adaptation strategy and said that "assisted migration could be one of our tools."
Meanwhile in BC, where 200 million trees are planted in the province every year, the upper range limit has already been extended by up to 400 km in some cases to allow the steady northward march of large populations—and in the case of the larch, an unprecedented thousand kilometer leap.
All the government officials I spoke with stressed that they were well aware of the potential for catastrophic habitat losses over the next century. Yet, none have yet committed to moving species beyond their natural range.
"There was a clearly crafted effort [in BC] to define assisted migration in a way that would distance it from exotic species"
So how did BC end up so far ahead on adaptation? Nicole Klenk, an environmental scientist and science policy researcher at the University of Toronto recently interviewed 46 scientists and policy actors across the country about the gap in adaptation efforts.
A dizzying array of answers were given: BC is facing more rapid climate change; BC had a commercial incentive to save the forestry industry; they were working with better trial data; the mountainous landscape prevents the gradual natural movement of species. Some interviewees grumbled about a lack of support, and "apathy and cynicism" within government elsewhere.
But, the paper argues, BC largely owes its success to presentation. It notes that scientists took great care to frame the changes as "business as usual," and "an opportunity to help nature," by expanding a tree species to an area it would be well adapted to in the future. "There was a clearly crafted effort to define assisted migration in a way that would distance it from exotic species," Klenk told me .
This isn't misinformation, says Klenk, but a very different view of the forest. "They had shifted from an ecological perspective to a genetic perspective, one that stresses population viability and adaptability," she told me. With this approach, the forest's ability to survive future challenges, like a changing climate, is prioritized over maintaining historical boundaries and ranges. BC was committed to this view, and avoided the conservation debates that have stalled efforts elsewhere.
However you frame it, the question may be whether we do it now, or continue to wait until later—and as global warming threatens more species, it's likely even the most staunch conservationist will want to see their favorite species head north before long. In a recent survey nearly 90 percent of ecology and conservation biologists said they would support assisted migration if it would save a species from extinction. Those decisions though, will have to be made soon.
BC looks very progressive, but in O'Neill's view they acted just in time. "We're only now planting for the changes in the next few years," he told me. People have different ideas about how urgent the need for action is, but most agree it's in in the next decade or so.
"We are even behind with some species," Hamann said. "I'd say now is the right time to make large scale changes."