Boreal forest adapts to development—to a point

(Edmonton) Northern Alberta’s boreal forest shows a surprising resiliency to human intrusion, but University of Alberta researchers warn the landscape has a definite breaking point.

The research team, led by graduate student Stephen Mayor, found that up to a certain point, plant life in the boreal forest responded to intrusions such as roadways and farm fields by actually increasing its biodiversity.

The researchers counted plant species in sites across the whole of northern Alberta—an area larger than Germany. They then used satellite and aerial photos to compare the numbers of plant species with the percentage of human-disturbed land versus the percentage of natural, undisturbed boreal landscape.

“It might be expected that the more disturbance, the fewer kinds of plants we would find,” said Mayor. “But we actually found more species were growing as the percentage of disturbed land rose.”

However, Mayor says, there is a tipping point when more than half of an area is visibly changed by human use. “When the amount of disturbed land in a study area began to exceed 50 per cent, a threshold was reached and we found fewer and fewer plant species.”

“Our research findings mean that the variety of plant life in the boreal forest can tolerate farms, forestry, even oil and gas extraction—but only in moderation,” said Mayor. “There are real and predictable limits to how much intrusion nature will allow.”

The researchers believe their study area, which encompassed all of northern Alberta including the oilsands, was the largest ever used in a study of this kind—an opportunity Mayor says he wouldn’t have had at another university.

“The University of Alberta enabled me to start answering questions about how humans alter the natural world, that might not be possible elsewhere.”  

The research was published Oct. 16 in the journal Nature Communications.