Lack of rain killing Canadian firs, experts say

Globe and Mail (Canada): You won't have trouble finding a pint-sized grand fir on a Christmas tree lot this time of year - it's one of the most popular yuletide evergreens on the market. But tree experts on southern Vancouver Island fear climate change is threatening the giant conifer's survival in the wild.

Chris Paul, an arborist with the Municipality of Oak Bay, said his staff have had to chop down dozens of dying grand firs in recent years, something that in past decades rarely happened. "Five or six years ago we started seeing a decline. We didn't used to have to cut them down," said Mr. Paul, who has worked for the Oak Bay parks department since 1996.

Mr. Paul said the grand firs are showing signs of drought stress. "Usually with drought stress, we're seeing the trees die from the top down... it takes a few years," he said. "If you look at the drier summers we have been getting, I think the climate is making a difference."

Found in abundance in the Pacific northwest, including southeastern Vancouver Island and the Lower Mainland, the grand fir thrives in wet, rainy conditions. Grown extensively on commercial Christmas tree farms, the fragrant conifer can reach heights of up to 75 metres and live to be 300 years old in the wild. Yet many of Oak Bay's grand firs are dying before they hit 100, Mr. Paul said, pointing to a scattering of ivy-covered stumps next to a chip trail winding through scenic Henderson Park.

In neighbouring Saanich, parks staff have removed dozens of middle-aged grand firs from Cuthbert Holmes Park, Knockan Hill Park and other areas in recent years. "Saanich has had quite a lot of grand firs die in our parks. It's generally being attributed to a lack of rainfall," said arborist Brent Ritsom, who has worked for the municipality for 20 years. "We are cutting trees down that are up to three feet in diameter. It's very unusual."

The grand fir can be highly sensitive to development, but Mr. Ritsom said many of Saanich's dying grand firs are located in forested areas where they would normally be expected to thrive.

Richard Hebda, curator of botany and earth history at the Royal B.C. Museum, said the grand fir's plight mirrors that of the western red cedar, another giant West Coast conifer that has been ravaged by changing weather patterns and the lack of summer moisture. "I'm almost certain the same issue is affecting the grand fir. Oak Bay is one of the driest parts of the Island," he said.

…Statistics from Environment Canada show no appreciable change in Greater Victoria's average annual rainfall over the past decade. But Mr. Hebda said the problem for trees like the western red cedar and the grand fir appears to be a change in rainfall distribution, resulting in wetter winters and drier summers.

"You have to think of these trees as humans. You can have water all year round and then if you have no water at all for two weeks, you could die," he said. Sensitive species such as the grand fir and the western red cedar are like a "canary in the forest," warning us that an ecological shift of even greater proportions is afoot, he added. "But this time we're going way beyond where we've been before."