Adirondack forests could see major changes in the coming decades as a result of forest pests, according to experts who attended a forest pest summit in North Creek recently.
Both the hemlock woolly adelgid and the emerald ash borer have been found south of the Adirondack Park, and the balsam woolly adelgid appears to be causing more damage to balsam firs inside the Blue Line in recent years.
“(Hemlock woolly adelgid) will surely take out all the hemlock trees slowly over a period of trees, unless some bio-control effort is successful, and I would say the emerald ash borer is quite likely to remove all the ash trees also,” said Gary Lovett, a forest ecologist with the Cary Institute of Ecosystem Studies in Millbrook.
Lovett was the keynote speaker recently at the Adirondack Forest Pest Summit held in North Creek. He was one of numerous experts who addressed the threat of forest pests to Adirondack forests. The event was organized by the Adirondack Park Invasive Plant Program, Adirondack Mountain Club, and state Department of Environmental Conservation.
Emerald ash borers have been found in 35 counties statewide, including a recent discovery in Oneida County. There are 900 million ash trees statewide, with many of them being found within communities. The loss of the trees in the Adirondacks would be serious, but scientists say their disappearance wouldn’t impact ecosystems as much as the loss off hemlocks.
“I can’t express my concern enough for the Adirondack forests because of this bug,” said Mark Whitmore, a forest ecologist at Cornell University, about the hemlock woolly adelgid.
Hemlock wooly adelgid was first found in the lower Hudson Valley in the 1980s. It is believed that it came to the eastern United States from southern Japan. In recent years, it has been found as far north as Schenectady, to the west in the Finger Lakes, and throughout New York City region and Long Island.
The tiny insect looks like a ball of cotton because it produces a dense mass of waxy hairs to protect itself. They are found on the underside of branches and needles. The insect injuries the tree when it uses its long teeth to extract sap and nutrients from the needles, which prevents tree growth.
The severity of the impacts of the adelgid are varied. They have little visible impact on some trees and appear to kill others over a period of a few years. In places like the Great Smoky Mountain National Park, thousands of hemlocks have died because of the adelgid.
Scientists are particularly worried about the loss of hemlock trees because they are a foundation species. That means they play a major role in defining and creating ecosystems. Hemlocks that die would likely be taken over by species that aren’t capable of playing the same role in the ecosystem, such as hardwood species. This could be problematic for stream systems that rely on hemlock forests to regulate water flow in soils, provide shade, and stabilize banks. Whitmore said one key characteristic of hemlocks is they provide shade that allows snow to melt slower in the spring, allowing streams to stay replenished for longer. In turn, this would hurt brook trout and salamander populations.
Forest composition maps of the Adirondacks show that hemlocks are extremely prevalent along the southern and eastern borders of the Park.
The Adirondack Mountain Club has taken a leadership role in trying to prevent the spread of the hemlock woolly adelgid with the formation of a backcountry forest pest monitoring program. In 2015, there were 44 volunteers enrolled. The volunteers took part in surveying more than 22 areas in and around the Adirondack Park.
But even with the volunteer efforts of groups like the Adirondack Mountain Club, it may be difficult to stop the spread of the insects. That’s because one of the main ways it travels is with birds.
“It has birds carrying it,” Whitmore said. “It’s going to be hard to stop.”
When the insect is found early, there are methods for eliminating it from trees. Foresters have used both pesticides and predator beetles for this purpose.
But the battle against forest pests shouldn’t just be fought and understood locally. Lovett said people need to understand the root of the problem. The pests are entering the United States on wooden packing crates and non-native plants used for landscaping. Overall, about 25 pests enter the United States every decade, Lovett said.
“The biggest pathways are wooden packing material, like crates and pallets, and also live plants that are brought in for the nursery trade,” he said. “If we can do something about reducing the pests on those pathways, then we can solve the problem in terms of getting new pests in. It’s not going to help us with pests that are already established, but it will help us with the next pests.”
Lovett said one way that people can help is to buy only native plants and encourage elected officials to pursue federal legislation that deals with the problems associated with global trading. For instance, he said wooden packing materials should be replaced with new materials that aren’t capable of hosting wood-boring beetles, such as the Emerald Ash Borer.
Photo provided: Hemlock woolly adelgid.