KITCHENER -- Close to two dozen ash trees will be removed from Royal City Park in Guelph this week due to hazardous conditions.

The emerald ash borer, an invasive beetle, is to blame.

"Can't climb the trees to cut the tops off and it's the safest way to remove them," said Timea Filer with the City of Guelph.

Once designated trees are down, they're broken down into smaller pieces.

"Then they'll take them to be chipped for wood to be used in our parks on trails," Filer said.

Crews will remove 21 trees from the park and it's part of a larger plan to remove hundreds of trees in natural areas.

"This is our ninth year of our emerald ash bore plan," Filer said. "We've been removing about 300 to 500 trees every year."

Filer said leaving them standing is hazardous.

"They become a danger once they die," Filer said. "They become dry and brittle."

The dead trees could fall at any moment.

"They get root tot and butt rot, which means they basically rot from the ground up," said Stephen McQuigge with the Grand River Conservation Authority.

The GRCA is also dealing with dead trees along sections of trail in Paris, Glen Morris and Cambridge.

"We want to get them on the ground so we can control where they come down and when they come down," McQuigge said.

New trees will be planted to replace the ones lost.