Dead or dying trees, also called snags, are sometimes viewed as an eyesore, but a B.C. scientist is warning that if they don't present a safety hazard, it's important to leave them be.
"There's systematic elimination of those roost trees and habitat trees because of forestry and safety concerns, residential and agricultural development 鈥� we have so few snags in our environment and so many species require them," said wildlife conservation biologist Christoph Steeger at a presentation this month in Nanaimo.
Steeger has spent a career researching wildlife trees, and his work has included a
"Because of forestry and other forces there are hardly any left and that's of grave concern."
His talk at the Beban Park Social Centre on Dec. 3, hosted by Nanaimo and Area Land Trust, was titled 'the importance of wildlife trees for bats,' but according to Steeger, bats are just one drop in a much larger bucket that includes martens, fishers, black bears and birds. Even caribou rely on the lichen from dead trees for food.
Among B.C. bats, 14 of 15 species roost in trees, 11 roost in dead trees and eight of them roost exclusively in dead trees. Often the maternity nests are made out of unused woodpecker holes in recently dead trees. Other species, like chickadees and nuthatches, require trees that were dead for even longer, so their beak can penetrate the 'spongy' wood.
"In British Columbia, at one point it became clear there was a systematic elimination of snags from our forests. I say systematic because when you have a clearcut, everything goes, and people were getting injured and the workers compensation board by law demanded that all snags be cut down before every harvest," Steeger said.
Combined with residential removing of trees, snags began disappearing en masse.
A solution was the , developed as a partnership between the B.C. government and the University of Northern B.C., which teaches professionals to identify the differences between a safe snag and a dangerous one. These factors include the tree's root system and the direction the tree may fall.
However, Steeger said the problem persists. The consequence of not having enough wildlife trees, he warned, is extinction. One example he gave was the ivory-billed woodpecker, which can no longer be found in the southern United States because its nest trees no longer exist.
The biologist noted just because a tree may be dead, its use in the ecosystem isn't over.
"When it's assessed properly, and there's people who are certified to do so, you can leave a snag behind 鈥� you don't have to cut it down."
