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Gatineau has given up on trying to save its ash trees and has contracted with a private firm to cut them all down, sick or not, in the next three years.
This will remove another 40,000 trees from the city, in addition to close to 30,000 trees (including some elms) that are already gone.
The city has concluded there’s just no way to stop the emerald ash borer, an invasive insect with no North American enemies that has eaten its way across the U.S. Midwest, then much of Ontario, and now Gatineau.
The city said dead elms are a danger to people and infrastructure. The trees become brittle after the ash borer kills them, and their trunks and branches tend to snap.
Gatineau had adopted a management plan for the ash borer, but concluded in a document last fall that “all the ash trees will become infested and will die.”
It had tried to cut all of the ash trees near walking and cycling trails, a measure to keep people safe from falling branches.
But this did not take into account the fact that people do not always stay on paved paths. Gatineau’s wooded areas sometimes have “informal” paths through them, and these too can pass close to dying ash trees.
There are also trees along streets, and as the ash borer spreads, the city concluded the only answer is to cut them down.
The ash borer was identified in Gatineau in 2011, but likely arrived there earlier.
In Ottawa, the city has been cutting trees that sicken and die, leaving those that are healthy for the time being. It has also inoculated some of the larger trees, particularly those in valuable locations such as big trees that shade playgrounds.
But inoculation (with a chemical called TreeAzin that kills the ash borer) is costly — roughly $200 per treatment, depending on the tree’s size, and repeated every two years. And it does not always work.
Ottawa still advises woodlot owners not to cut all their ashes right away, but to wait until they die.
“There is no immediate need to remove an infested ash tree from your property. A tree, even in decline, can offer shade, produce extra oxygen and contribute to a better environment. But if you want your tree removed or if you feel the tree in your yard has become unstable and could fall and damage either property or people, please contact an arborist immediately,” the city’s website on the ash borer says.
So far, no state or province has come up with a way to save most of the ash trees that once formed about one-quarter of the forest canopy in Ottawa. Ash was widely planted in many cities in eastern North America in the 1970s, replacing elms that had been killed by Dutch elm disease.
Green ash is considered more susceptible to the ash borer than white ash. Unfortunately, green ash is the dominant species here.
Gatineau said it will spend about $2.3 million over the first two years of the three-year cutting program. The wood can’t be used for much, but the city says it can be burned.
Meanwhile, there’s a new tree-killing disease on Ontario’s southern border. Oak wilt, caused by a foreign fungus, is on the U.S. shore of the Detroit River, a few hundred metres from Windsor.
tspears@postmedia.com
twitter.com/TomSpears1
查看原文...
This will remove another 40,000 trees from the city, in addition to close to 30,000 trees (including some elms) that are already gone.
The city has concluded there’s just no way to stop the emerald ash borer, an invasive insect with no North American enemies that has eaten its way across the U.S. Midwest, then much of Ontario, and now Gatineau.
The city said dead elms are a danger to people and infrastructure. The trees become brittle after the ash borer kills them, and their trunks and branches tend to snap.
Gatineau had adopted a management plan for the ash borer, but concluded in a document last fall that “all the ash trees will become infested and will die.”
It had tried to cut all of the ash trees near walking and cycling trails, a measure to keep people safe from falling branches.
But this did not take into account the fact that people do not always stay on paved paths. Gatineau’s wooded areas sometimes have “informal” paths through them, and these too can pass close to dying ash trees.
There are also trees along streets, and as the ash borer spreads, the city concluded the only answer is to cut them down.
The ash borer was identified in Gatineau in 2011, but likely arrived there earlier.
In Ottawa, the city has been cutting trees that sicken and die, leaving those that are healthy for the time being. It has also inoculated some of the larger trees, particularly those in valuable locations such as big trees that shade playgrounds.
But inoculation (with a chemical called TreeAzin that kills the ash borer) is costly — roughly $200 per treatment, depending on the tree’s size, and repeated every two years. And it does not always work.
Ottawa still advises woodlot owners not to cut all their ashes right away, but to wait until they die.
“There is no immediate need to remove an infested ash tree from your property. A tree, even in decline, can offer shade, produce extra oxygen and contribute to a better environment. But if you want your tree removed or if you feel the tree in your yard has become unstable and could fall and damage either property or people, please contact an arborist immediately,” the city’s website on the ash borer says.
So far, no state or province has come up with a way to save most of the ash trees that once formed about one-quarter of the forest canopy in Ottawa. Ash was widely planted in many cities in eastern North America in the 1970s, replacing elms that had been killed by Dutch elm disease.
Green ash is considered more susceptible to the ash borer than white ash. Unfortunately, green ash is the dominant species here.
Gatineau said it will spend about $2.3 million over the first two years of the three-year cutting program. The wood can’t be used for much, but the city says it can be burned.
Meanwhile, there’s a new tree-killing disease on Ontario’s southern border. Oak wilt, caused by a foreign fungus, is on the U.S. shore of the Detroit River, a few hundred metres from Windsor.
tspears@postmedia.com
twitter.com/TomSpears1
查看原文...
