Volunteers aim to save centuries-old hemlock trees from invasive insect

A group of volunteers has been working to save a rare stand of centuries-old eastern hemlock trees from a potentially devastating invasive insect.

The massive conifer trees are located on the central island of Sporting Lake within the Tobeatic Wilderness Area, and they're at risk of being infested by the hemlock woolly adelgid.

To give the trees a fighting chance, Nova Scotia's Environment Department issued a permit to the group, allowing them to inject the trees with an insecticide that's often used to treat fleas on pets.

The adelgid has been wreaking havoc on hemlocks in eastern North America — including Nova Scotia — for years.

The tiny bugs, native to the Pacific Northwest and Japan, kill trees by attaching themselves to the base of hemlock needles and feeding on sugars, starving the tree of nutrients. While feeding, they produce a woolly-looking substance visible on the underside of the needles.

The volunteers are working to prevent an infestation that would devastate the trees on the island.

"I paddle the Tobeatic a lot, and if I came here and the trees were all dead — which is certain to happen if they're not treated — I just couldn't deal with that," Scott Robinson, the group's operations chief, told CBC Radio's Information Morning on Tuesday.

Robinson said the trees are part of one of the last intact old-growth forests in the Maritimes, and the volunteers are desperate to save the lush, mossy landscape canopied by the towering hemlocks.

"It's just a magic, magic place. It feels like church to me," he said.

The volunteers even raised more than $125,000 to cover the costs of the insecticide.

Robinson is among dozens of volunteers that have been injecting the trees by drilling holes into their base and then inserting a nozzle connected to a pressurized canister filled with the insecticide.

Matt Miller, a forester from Pictou County, has been working on the trees. He said he understands that some people might be concerned about the use of insecticides.

However, he said it's a proven treatment that has worked in forests in the United States.

"Within a couple of minutes. It's all delivered directly into the tree. Very targeted, very safe and effective," Miller told Information Morning.

He also said it's incredibly necessary. 

The hemlock woolly adelgid has been in Nova Scotia since 2017 and has been killing trees from Digby to Yarmouth.

"I think the group feels we're a little bit behind the 8-ball, even four years into this outbreak. A big part of why we're here is to try to raise awareness about the pest [and] raise awareness about the options that we have to protect our forest," Miller said.

Donna Crossland, a retired biologist from Kejimkujik National Park and National Historic Site, said she has a "deep concern" for the eastern hemlock on the island.

"It's such an interesting conifer tree because it's the conifer that grows with the greatest girth, and yet it's the most delicate," Crossland told Information Morning. 

"It has the tiniest needles, and so it has this lacy, feathery, delicate appearance and yet you have these big lateral branches coming off these stout trunks. It's absolutely breathtakingly beautiful."

Crossland said she hopes the group's efforts will allow the next generation to visit the island and appreciate its beauty.

"I feel that we owe this forest to do our best to protect it," she said. 

"And I think many Nova Scotians would — even if they never get to see this place, but they get to see some photos of it — I think many of them would give this forest their blessing."