2021-09-08

Parks Canada seeking public input on a plan to fight Hemlock Woolly Adelgid at Keji

Local Journalism Initiative Reporter

There's just a day left to have your say about a Parks Canada plan to battle the Hemlock Woolly Adelgid (HWA), which is taking over the hemlock tree stands in Kejimkujik National Park and National Historic Site.

"It is quite a concern once you start looking into it and see the devastation it has caused in the U.S.," said Matthew Smith, Parks Canada Ecologist and co-chair of a task force working to fight HWA. "It is not good for Kejimkujik. The beautiful stands provide a lot of ecological services for plants and animals and it is a big draw for people."

As part of a five-year project, Parks Canada has put together a plan to combat HWA and is asking for public input. All comments must be submitted September 10 by email to pc.LetsTalkKejimkujik.pc@canada.ca." target="_blank">pc.LetsTalkKejimkujik.pc@canada.ca. Comments will guide Parks Canada in its next steps.

Parks Canada is part of a task force, the Hemlock Woolly Adelgid Working Group, that is working closely with several stakeholders such as the Medway Community Forest Co-op, the Canadian Food Inspection Agency, the Nova Scotia Department of Natural Resources and the Canadian Forest Service. The department is also working closely with the Mi'kmaw community, considered to be co-managers of the forest.

Native to Asian countries, HWA has been in the United States since the 1950s and is believed to have been brought to the country through a Japanese garden located near Washington, D.C.

The tiny, poppy see-like insect makes its home at the base of hemlock needles. Encapsulated by a white, woolly substance, it has a long straw-type appendage that it uses to suck the nutrients out of trees. This causes the tree to starve and eventually die.

HWA can be spread by wind, as well as people moving firewood from one region to another.

The battle against this invasive pest has been going on in Nova Scotia since it was discovered in the Yarmouth area in 2017. By 2018 it had moved to trees in Kejimkujik, a place that has some of the oldest and largest hemlock stands in the Maritimes, with some trees dating back 400 years.

Once infected, trees can die within three years.

According to Smith, there are three ways to fight HWA: silviculture, insecticide and a more of a long-term solution, the introduction of predators such as beetles.

Set to begin in October if approved, the plan will see Parks Canada staff use a combination of silviculture (removing about 3,500 hemlock trees with the majority in Jeremy's Bay campground) and an injection of neonicotinoid (imidacloprid) pesticide into 1,500 trees.

"It's known that this systematic insecticide is effective against HWA and helping hemlock trees survive," said Smith.

He added that the insecticide would have no negative impact for plants or terrestrial species. Soil and aquatic invertebrates and arthropods may be impacted, but there will be efforts to mitigate this.

The imidacloprid treatments last between five and seven years and further treatment may be required.

Treated trees will be marked. Members of the Mi'kmaw community often use parts of the tree for traditional healing methods in teas and health treatments.

Silviculture to thin out trees would bring more sunlight into the tree stands. Smith noted there has been some evidence that the extra light can decrease HWA, which like a more shady environment.

Along with control of the HWA, the plan also is to plant 5,000 trees over the next two years to shift the forest away from the hemlock trees. Hardwoods native to the area, such as red oak, yellow birch, sugar maple and red spruce, would be planted to work along with the softwood trees that are doing well on the forest floor.

Now is the time to act against HWA, said Smith.

"Time is running out ... Once they're infested, we really have just a three-to-10 year range before they die. As they become more infested and decline they'll be less responsive to any use of insecticide," he said.

The aim is to use the five-year project as a "restoration-type" effort that hopefully will restore some of hemlock forest in the park, while knowing not all the hemlock trees will be saved.

"We're working to slow the spread and understand the impact of our ecosystem if we lose the trees. We know we can't protect them all. But if we can protect some of this old-growth forest for future generations it will serve as a way to show people a bit of what hemlock forests once were," said Smith.