The Grand River Conservation Authority (GRCA) may have to come up with $5 million to combat Emerald Ash Borer (EAB). And although GRCA staff is not pointing to an all out infestation of the ash-killing beetle, they are cautioning that money should be put aside for an anticipated invasion.
Communications manager Dave Schultz said a minor infestation has been found in ash trees on GRCA-owned property in the Cambridge area. It’s estimated six per cent of the trees on GRCA properties are ash trees. The beetle attacks and kills only ash trees.
The concern, particularly on property open for public use, is potential for injury from falling trees infested with the beetle.
“We’re responsible for it on our property,” Schultz said. “We have to maintain them (ash trees) for public safety.”
The Emerald Ash Borer is native to eastern Asia and since its inadvertent introduction around 2000 in the Detroit-Windsor area, its has quickly spread to other parts of Ontario, according to a report from GRCA watershed forester Virginia Gordon presented to the board Aug. 24.
“Ash is a common tree in both urban and rural settings. Ash accounts for approximately 25 per cent of hardwood forests in southern Ontario and about 15 per cent of urban trees, locally,” the report stated. “EAB infestation typically eliminates ash in about a decade, resulting in economic, environmental and social impacts in the community. Affected municipalities in more advanced infestation areas have already incurred substantial costs related to increased tree removal and replacement.”
Some indications are an infestation can kill an ash tree within three years.
Schultz said GRCA staff will be looking at where there is a potential infestation on its properties and how advanced the infestation might be.
The GRCA has not set aside any money to deal with the infestation, but Schultz said it will be something the authority will look at as it prepares its five-year plan.
“EAB does not spread quickly on its own, but rather, through human activities, mainly the transport of infected materials into previously uninfected areas,” the report said. “Firewood movement is thought to be one of the chief dispersal mechanisms, although wooden crating material from Asia was the transport mechanism of the original arrival in North America, and continues to be an issue. Regulatory control has unfortunately not been able to stop the spread.”
Chemical and biological control options have either been approved or are in the development stage.
“Those forests with few ash trees are likely to have a quick, strong rebound after EAB infestation, and retain many of their ecological and social values, despite the loss of ash. In many cases no human intervention will be necessary in order to sustain forest structure, function and ecological integrity,” the report stated
Studying the GRCA’s ash population may require more inspections because of the short life span of infected trees, the report contends.
“To mitigate the negative impact of the substantial amenity tree loss in the parks and other high use areas, an increased amount of tree planting in those areas will be considered. A small number of high-value amenity ash trees may also be selected for injection through a bi-annual insecticide treatment program,” the report also suggested.
