[getsmart-l] Poison Ivy:- "But that policy may have to be reconsidered with global warming."

[John O'Gorman]

" "Which makes the policy (of Toronto Parks Dept.) of keeping poison ivy in a healthy woodland ecosystem up for review. "The government is committed to sustainability [of the ecosystem]," Mr. Bakowsky says, "but what we have today will change and is changing right now. Certain species will migrate more quickly." " Then there is the dog-strangling vine and garlic mustard which have become utterly invasive. Is this the time when we need "spot-spraying" of herbicide?


http://www.theglobeandmail.com/servlet/story/LAC.20071020.IVY20/TPStory/?query=poison+ivy
CREEPING PESTS

High Park gets a rash of poison ivy. Don't worry. Just keep to the path
LAURA LIND Special to The Globe and Mail October 20, 2007

As one wanders through the lovely fall colours of High Park, one sees the sumac, the maple, the ... er ... poison ivy? Yes, poison ivy turns a deep red in late-stage summer and fall, and High Park, apparently, is full of it.

Park management doesn't keep quantitative data on the spread of poison ivy, but, anecdotally, the hot dry summer of 2007 helped Toxicodendron radicans flourish. There are now multiple poison-ivy-warning signs posted throughout the 160-hectare grounds. 

One staff member at the High Park Nature Centre contracted poison ivy four times in two months. "There's quite a bit in the park," another staffer says.

Eighty per cent of the human population reacts to poison ivy. The active component, urushiol, is toxic enough for use as a chemical-warfare agent by the U.S. military. 

At the Nature Centre, the standard advice to park visitors is to stay in the centre of the dirt paths and keep dogs on a leash in the on-leash woodland areas. Otherwise, staffers contend that poison ivy is part of a healthy woodland ecosystem. "It prevents erosion because it prevents people from walking through protected areas, and provides berries for the woodland animals," a staffer says. 

But that policy may have to be reconsidered with global warming. Wasyl Bakowsky, a community ecologist with Ontario's Natural Heritage Information Centre, says that "every year is a good year" for poison ivy, and the spread of the plant has been on an increase for the past 50 years. 

He cites a 2006 Duke University study that tracked the response of poison ivy to rising carbon-dioxide levels. After six years of monitoring ivy in a lab, scientists concluded that poison ivy thrives with higher carbon-dioxide levels and intensifies in toxicity.

Which makes the policy of keeping poison ivy in a healthy woodland ecosystem up for review. "The government is committed to sustainability [of the ecosystem]," Mr. Bakowsky says, "but what we have today will change and is changing right now. Certain species will migrate more quickly."

It's a tough little plant to get rid of. You can't burn it, because it releases urushiol molecules into the air. You have to yank it out, roots and all, because every bit of the plant contains the resin.

Doug Smith, a parks and recreation standards officer, says the presence of poison ivy "to any degree" is considered an emergency. If the ivy is close to a public trail, park staff will either remove the plants or post signs. 

But, he adds, "You go off the beaten track and all bets are off. You're going to get ticks, burdocks, snakes. That's the choice you make. 

"It's a habitat for different things," he adds. "You can't eradicate all of this stuff. "
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