Home  |  Elm Care Products
 
Home > Elms in Winnipeg March 2000 - Part 2

 Last Update 02/04/07  

Main Topics
  How Trees Work
  About Elm Trees
  Caring for Your Elm
  Elm Tree Diseases
  Elm Tree Links
Quick Elm Facts

Part 1   Part 2   Part 3   Part 4

Winnipeg's early planners had a perfect source of planting stock at hand. When the time came to bring trees into the newly laid-out subdivisions on both sides of the Assiniboine and Red rivers, they simply collected native elms from the riverbanks. Each new city park featured a nursery where the trees were grown to sapling size before being transplanted along the generous boulevards. The city charged each homeowner a lot levy and planted an elm in front of every residence, and Winnipeg's splendid urban forest was born. It's a democratic forest, lining not just the tonier streets of southern neighbourhoods but also offering shade and comfort to people in Winnipeg's storied north end, where successive waves of poor immigrants-most recently aboriginal people from reserves-have settled in the rundown streets around Selkirk Avenue.


"Our forest is unique in the world," enthuses chief forester Mike Allen as he surveys the elms that shade Palmerston Avenue in the Wolseley district. "There's no other city anywhere with this incredible natural arch of trees." A tall, thoughtful man with the image of a tree etched on his brass belt buckle, Allen grew up in Toronto at a time when the dreaded Dutch elm disease was obliterating the elm from the city's parks and lawns. "When I was eight," he says, "I noticed workers removing one giant after another along my route to school, and whenever I travelled around southern Ontario, I witnessed the death of elms standing like weird witch's broomsticks." He has vowed not to let that happen in Winnipeg. He points to a four-storey elm and describes the multipronged fight he has waged against Dutch elm disease, explaining that the trees' rough and diverse origins on the banks of the Assiniboine were the key to their survival. 
"They're not high-tech clones cultivated for certain desirable traits," he says. "They were selected purely from native stock, so they had tremendous genetic diversity even though they were all one species. Today, I can show you elm from all over Winnipeg, all American elm, but you might look at one and say, "That's not the bark of an American elm.' " 
As we tour the city's forest, it becomes clear that most Winnipeg elms have the elm's characteristic bark, deeply furrowed and light grey, like a heavy grade of rough corduroy. Some, however, have no fissures or ridges, and the bark is dark or tinged with brown. Sometimes the leaves are enormous; sometimes they're small. Some leaves have sawtooth edges and grow in double rows; sometimes the edges are wavy and the rows are triple. Such variation makes for a more resilient species, because certain variants seem to have an inherent resistance to Dutch elm disease. Not all of them, however. Five years ago, in the biggest single elm infection that Winnipeg has witnessed, the disease destroyed 20 mature elms at Palmerston and Ethelbert. The memory still makes Mike Allen shudder. But the resilient variants survived the infestation, and their genetic material may help save the species.


Dutch elm disease, so named because it was first identified in the Netherlands in 1917 or 1918, likely originated in Asia. It's an infection of the deadly fungus Ophiostoma ulmi, which enters and disrupts the tree's vascular system literally on the back of the elm bark beetle, Hylurgopinus rufipes. The scourge reached the United States in 1930, with the first Canadian outbreak reported in Sorel, Quebec, in 1945. Within a few years, more than 600,000 elms in Quebec had been wiped out. Toronto's population of 35,000 elms was quickly reduced by 80 percent. According to the University of Toronto's Martin Hubbes, a leading Dutch elm disease researcher, "one of the largest mass destructions of trees ever witnessed" accelerated when the Canadian and American disease fronts merged and began to migrate westward, travelling up the Red River from South Dakota into southern Manitoba in the early 1960s, most likely brought in by campers hauling infected firewood. The disease was reported in Winnipeg in 1975 and by 1990 was infecting elms in Saskatchewan. This year, it arrived in Alberta. Today, possession of elm firewood-infected or not-can bring a $5,000 fine in Winnipeg, where they take the threat seriously. Since the disease's arrival, some 34 percent of city elms have been infected and cut down. 


It's a paradoxical story, at least as far as Winnipeg is concerned. The same riverbank forests that provided the city with its rich genetic diversity now offer an ideal host for Dutch elm disease. Because the Assiniboine, La Salle, and Seine rivers empty into the Red near Winnipeg, their rich silt valleys provide both a breeding ground and a highway for the elm beetle. The province has earmarked and sporadically protected a buffer zone surrounding Winnipeg. This is a crucial battlefield in the war to save the city's cherished elms. The idea is to remove infected trees from this zone in an attempt to protect the city proper. Other western cities that depend on the elm for shade, shelter, and beauty are luckier because they are more like isolated islands in the prairie, with little contiguous elm forest.


Another paradox. Despite the devastation of the urban elm forests of Toronto and Montreal, those central Canadian cities are well situated to bounce back. Their relatively moderate climates can support a wide variety of trees, from the colourful red maple to the elegant black walnut. Winnipeg's famously frigid winters mean that few species can thrive there. The American elm, one of the hardiest, is ideal. Not only sublimely beautiful, it's tough enough to resist road salt and devastating cold. What's more, Winnipeg's harsh winters have little appeal for the European elm bark beetle, Scolytus multistriatus, a larger, hairier critter that's a perfect host for the toxic fungus. As long as Winnipeg has only the native prairie variety, its elms have a fighting chance. Yet Mike Allen remains cautious.
"Insects are highly versatile and opportunistic," he warns. "It may well only be a matter of time before we get European beetles reproducing themselves and becoming hardy enough to invade Manitoba."

Part 1   Part 2   Part 3   Part 4

Jamie Swift is a writer and broadcaster living in Kingston, Ontario. His most recent book, Wheel of Fortune, was published in 1995. He is also the author of Cut and Run, a lament for the mismanagement of Canadian forests.

 


Thank you for visiting Elmcare.com!

Site Map  |  About this site  |  Home
www.TreeHelp.com
Copyright