Work has begun to treat trees for Hemlock Woolly Adelgid (HWA) at Kejimkujik National Park and National Historic Park.
“We have treated about 150 hemlocks using stem injection of imidacloprid pesticide,” reported Matthew Smith, a Parks Canada ecologist and co-chair of a task force working to fight HWA. “We started this on the hemlocks and hardwoods trail, treating some of the most majestic trees in the park.”
He said work is being done by Parks Canada staff while some technicians from the Canadian Forest Service have helped. Work to treat the trees will continue until freeze-up along the Hemlocks and Hardwoods trail, plus a few other areas such as the campground and in some of the back country sites as well.
The tiny adelgid was discovered in Kejimkujik in the summer of 2018. It attaches itself to the needles of Hemlock trees, sucking the life out of them. It’s identified by the white woolly covering it creates.
To combat this, imidacloprids are injected into the base of a tree and the circulatory system of the trees takes it up through the trunk and limbs and kills the insect. The treatment could last up to seven years.
According to Smith, the treatment is quick acting and highly effective with a tree obtaining better health within a year or so. Otherwise, once HWA takes hold of a tree it can kill it within three years.
Smith is glad they are doing this early in the process for much of the hemlock stand along the trail.
“We’ve caught some of these trees early, so if you look at many of the trees they are definitely infested with HWA, but they’re not at the point where they’re as bad as many other spots in the province,” he said. “I think we caught it early enough that we should see a big difference in the treated trees and the untreated trees soon.”
Parks Canada is working with partners including the Mi’kmaq of Nova Scotia to identify other priority stands within the park and undertake a triage-style of approach when identifying stands that need to be treated based on size, age health and their ecosystem.
He admits that they won’t be able to save every tree, considering that an estimated nine per cent of the forest stands in Keji are hemlocks.
“It’s a big area and doing this type of treatment takes time and we’re really up against it considering how fast the infestation is moving,” Smith warned.
This is the third year of a five-year project that started in 2019. The project has been provided $2.1 million over the five years to protect the hemlock forest.
Along with the treatments, some silviculture and some planting is being done to help the hemlock stands be more resilient. The plan is to plant about 5,000 trees over the next two years to shift the forest away from the hemlock trees.
Hemlock stands in Nova Scotia play an important role in the Acadian Forest. They are very old, some up to 400 years of age, and they’re unique in terms of being exceptionally tall and large in diameter.
“They serve species that like bigger trees like nesting owls, pine marten and even species like moose and deer that like overwintering under these huge, towering hemlocks,” said Smith. “They are also found along rivers and streams shading the rivers and making them cooler for cold-water fish like trout and salmon and other species that like cool, dark and moist environments like lichens and fungi,” he explained further.
Kevin McBain, Local Journalism Initiative Reporter, LighthouseNOW Progress Bulletin