Thursday, 9 August 2012

Winnipeg's Urban Forest and the Dutch Elm Battle

Skyline of Trees !
Yes, that's the West End under there !

On today's Winnipeg Internet Pundits radio show on UMFM we were asked to talk about something that makes Winnipeg a great city (vote for yours at the website !) I chose the topic of our incredible urban forest.

Whether at street level looking up or peering down from on high, the city's 8 million trees, 280,000 of which are on boulevards, are an impressive and important part of our city.

Here's a bit of history about our trees and the arrival of the disease that is slowly killing them off.

March 17, 1905, Manitoba Free Press

In 1900 Winnipeg's parks board created a boulevard committee with Alderman, lumber magnate and future mayor John Arbuthnot as its first chair. Its role was to create boulevards along city streets and to green them.

In the 1904 - 05 budget year the committee added 11 miles of boulevard, bringing the city's total to 60. They also planted 6,000 trees and budgeted for 3,000 more in 1906.

April 10, 1905, Manitoba Free Press

The tree of choice, not surprisingly, was the American Elm. They were natural to the region, especially plentiful along our riverbanks, and had long been favoured by both the parks board and private property owners for their heartiness and wide canopy.

Right up until the mid 1950s the elm made up 90% of the parks board's annual tree plantings, (the rest were ash.) By 1975 the city boasted a population of 250,000, North America's largest urban elm forest.

May 20 1970

In 1970 alarm bells rang when Dutch Elm Disease was found in the Red River watershed south of the border. Experts predicted that it was just a matter of a couple of years before it would arrive in Winnipeg.

Dutch Elm was not a new disease. Reports began appearing in the 1920s about the fungal infection, believed to have originated in Asia, that was ravaging Europe's elm population. (Named Dutch because it was Dutch scientists that identified the disease in the late 19-teens, similar to how "Spanish" flu got its name.)

In 1930 the disease arrived in the New England states and in 1944 it appeared in Montreal.

March 28, 1956, Winnipeg Free Press

In the mid 1950s the city was on high alert for the disease and exploring treatments and alternative species.

In 1956 residents of Oak Street, which had a newly installed boulevard, petitioned the parks board to plant a mix of species rather than one that might be killed off in a few years. The board originally rejected the request but Thomas Hodgson, the city's park superintendent, went to bat for them and its boulevard became a test case for to see how other species of trees survived and grew on Winnipeg's boulevards.

January 2, 1976, Winnipeg Free Press

Dutch Elm Disease was first discovered in Manitoba in 1975.

It was thought that American campers brought it up with them as the initial outbreaks took place around campsites. One group fingered by the Canadian Forestry Service as a likely source was the Wally Byam Caravan Club of Airstream enthusiasts. Thousands came from across the U.S. to Brandon in the summer of 1975 for a get-together. They then split up and travelled around the province.

In 1976 the city put a $200,000 battle plan in place. It consisted of a 40 man crew that inventoried public trees and pruned those that were ailing and thus most at-risk of succumbing. The province picked up about half of the tab and agreed to pay the cost for removing trees from private property.

That summer there were three new outbreaks in the province, the worst in East Selkirk. In the park adjacent to the hydro generating station 2,000 trees were burned to prevent it from spreading to the riverbank. Brandon's Curran Park was also infected.

In Winnipeg, between 25 and 35 diseased trees were found in Wildwood Park and a handful of isolated cases were found elsewhere in St. Vital before the summer was over.

Broadway's four rows of elms ca. 1902 (source)

In August 1976 the city and province began working on an $800,000 strategy for 1977. This involved an accelerated inspection and pruning schedule, fungicide spraying, public education and an expansion of a tree disposal program. In April 1977 a citizens advisory committee made up of representatives from each of Winnipeg's eight horticultural societies was struck to help designate priority areas for treatment.

By 1980 the city was spending about $1.5 m annually on Dutch Elm eradication, an amount that remained unchanged through the decade and the city was soon losing about 1,000 trees per year.

August 26, 1989, Winnipeg Free Press

In summer 1989 the disease rate exploded three to five fold. In Southern MB there were 12,000 confirmed cases found and in Winnipeg 5,600 trees were slated for removal compared to just 1,200 the year before.

There was an initial funding boost but in 1991 and 1992 both the federal and provincial governments cut their funding to the city to fight the disease citing the need for restraint in recessionary times.

In 1992 the city got help from a new citizens group called the Coalition to Save the Elms (now called Trees Winnipeg). The group was credited as being a difference maker in stemming the spread of the disease and raising citizen awareness.

Last year the city spent about $3.6 million fighting Dutch Elm Disease. Still, Winnipeg loses between 4,000 to 5,600 elms every year.

There's also a new threat coming, this time to our ash trees. The emerald ash borer is an insect killing of ash trees. It hasn't been found in Winnipeg yet but has taken root in cities like Toronto.

Winnipeg Tree Facts City of Winnipeg
Dutch Elm Disease Program City of Winnipeg
Dutch Elm Disease Program Province of Manitoba
5th Canadian Urban Forest Conference Proceedings (search 'Winnipeg')
Coalition to Save the Elms (Trees Winnipeg)

City Welcomes new tree preservation group Canstar
City to draft new strategy to protect elm trees Free Press (2012)
Vaccine for Dutch Elm gets OK from Ottawa Free Press (2009)
Dutch Elm Disease: An old enemy returns CBC Archives (2004)
Winnipeg brings Dutch elm disease under control CBC Archives (1992)


Paul Clerkin said...

From my house in Crescentwood there's noticeable gaps now in the Elm coverage. I look out back and there's a missing one on the next street, and the one next to it looks dead. And one further down. Out front, there's several been removed in last five years. If it keeps up like this on our street, we could be mature treeless in 20 years.

John Dobbin said...

The green bands along major streets have also seen trees and other vegetation devastated by salt from winter snow clearance.

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