Wild bees thrive after forest fires

SAN FRANCISCO: For most people, there is little reason to believe forest fires are good. But an Oregon State University study suggests fires could lead to greater abundance and diversity of wild bees.

Part of the first year of a two-year project, the finding was presented at the annual conference of the Ecological Society of America in Portland.

Field researchers led by Jim Rivers, a university forest wildlife ecologist, began trapping bees at 43 sites burnt by the 2013 Douglas Complex fire north of Grant’s Pass, which affected more than 18 000ha of forest in southern Oregon.

In low-severity spots, flames were confined to low-growing vegetation and did not reach the canopy.

Sara Galbraith, a post-doctoral researcher at the university’s college of forestry, told the conference there was not a lot of evidence of fire in such areas, except for the blackened parts of some tree trunks.

By comparison, at some of the high-severity fire sites there was a completely open canopy. There, Galbraith saw a lot of flowering plants in the understorey because the light limitation was gone.

“It just looks completely different,” she said.

Funded partly by the US Federal Bureau of Land Management, the researchers attracted wild bees by reflecting ultraviolet light which the insects took for a huge flower.

Once the bees got inside, they were unable to fly out from the trap.

As there are more than 500 species of native bees in Oregon that are important pollinators of wild plants and crops, the researchers noted, the findings suggested fires may promote bee populations that in turn influence agricultural productivity and floral diversity. – Xinhua