Weather killing Edmonton birch trees, researcher says
Researcher says Edmonton has lost 60 per cent of birch trees since 2008
A study is looking into why birch trees are dying off in the prairies and British Columbia, but a researcher says they can be saved.
Natural Resources Canada started the study in 2008 to focus on the state of birch health. The study has examined over 300 birch tree plots in urban centres.
David Langor, a research scientist working on the study, noticed birch trees were starting to die off at a rapid rate in 2003 and set out why.
Langor says Edmonton has lost 60 per cent of its birch population since 2008. So far he's found that the deaths are climate related. He speculates it's a combination of drought and more frequent freeze-thaw periods in the winter.
"Birch is a very shallow rooted species, so it's likely to show impacts of drought soonest," said Langor.
Birch is a very shallow rooted species, so it's likely to show impacts of drought soonest,- David Langor
"We get sap movement, and that's followed by freeze-up. That's likely causing some damage to the conductive tissue. This all manifests in the death of the top of the trees."
That's where a beetle — the bronze birch borer — works its way into the dead part of the tree and continues to slowly move through the trees.
Some birch trees show no sign of death at all. Langor is still trying to find out why those particular trees aren't threatened.
Birch trees can be salvaged
Langor says that even if the tree is dying, there still is hope.
Often the lower branches of birch trees are still alive while the top branches are dead. The trees can be cut above the live branches and inspected for insects.The still standing portion of the tree is expected to survive.
"The live branches below that cut will take over leadership and will continue to grow," said Langor. "The tree will look beautiful within three or four years."
He says dead branches and other parts of the tree can make for firewood, but if not burned immediately the insects inside the wood may be spread to other trees.
Langor also recommends pruning off dead branches as they are a safety risk during high winds.
A report on Langor's findings is expected to be published early next year.