Satellites may track invasive pests
The approximately 250-acres of sick hemlock trees on the eastern shore of Lake George were likely infected by the invasive hemlock woolly adelgid for five years or more, experts said last week.
The timeline is leading some to ask how to detect infected trees sooner, and the answer could be sky high.
A camper at the Glen Island Campground reported the declining hemlocks last month. The state and partner organizations followed up with surveys of the Fort Ann and Dresden area.
“The infestation that we are finding is older than we had hoped and larger than we had hoped, obviously,” said Rob Davies, the state’s forester.
The invasive bug has the potential to completely change the landscape around Lake George. The forest in the watershed, Davies said, is 80 perfect hemlock trees.
As it tackles this infestation, the DEC and partner organizations are looking at ways to spot hemlock woolly adelgid besides boots on the ground.
The DEC, the Adirondack Park Invasive Plant Program and The Fund for Lake George announced during a virtual press conference on Tuesday the creation of the “Save Our Lake George Hemlocks Initiative.” The Lake George Land Conservancy, City University of
New York’s Advanced Science Research Center, Cornell University ’s New York State Hemlock Initiative, the U.S. Forest Service, Adirondack Research and others are also taking part.
The initiative will use satellite imagery to detect changes in hemlock trees and deploy field crews more strategically, said Andrew Reinmann, an environmental scientist and assistant professor at CUNY. While the imagery won’t be the highest of resolutions, Reinmann said it could help detect changes in the greenness of hemlocks.
Davies said the 250 acres already identified along Lake George is made up of rugged terrain and steep cliffs. Surveying takes a lot of manpower and hours, but satellites could narrow down where field crews need to take a better look.
First, the initiative plans to use imagery from NASA’S Landsat satellites and the European Space Agency ’s Sentinel satellites, covering about 4,400 square-miles from Troy to the north end of Lake George. Staff will review the last five years of satellite imagery to see if they can spot the decline in hemlock health.
Other satellite, infrared and aerial technology may be brought in over time to enhance the survey efforts. Ultimately, said Eric Siy, “the intent is to create
something ready-made that can be applied parkwide,” to detect the invasive bug. Siy is the executive director of The Fund for Lake George.
The initiative will cost $125,000 for on-theground surveys and reviewing and interpreting the satellite imagery, at least through the spring of 2021.
“This is a marathon,” Siy added. “We want to be fully equipped to finish this marathon eradicating hemlock woolly adelgid and showing others how it can be done through partnership, through science and through an unrelenting commitment to success.”
In the meantime, DEC and partners will treat the already detected infected trees on Lake George with two kinds of pesticides, applied at the base of the trees. That is expected to start in the next week or so.
Woolly adelgid are tiny aphids that feed off of
hemlock’s twigs. The small bugs are often transported by birds and other wildlife. The 250 acres on Lake George is the second recorded infestation in the Adirondack Park. In 2017, a couple of infected trees were spotted on Prospect Mountain in Lake George and successfully treated with the same pesticides.
Zachary Simek, conservation and GIS analyst with the Adirondack Park Invasive Plant Program, said there is good news. Most of the infected hemlocks haven’t experienced a significant decline in health, he said, giving experts hope that the pesticide will work and save the trees. Davies said the applications will be over the course of years, however.
Davies also said the DEC is in discussion about bringing in a biological control — that is a fly or a beetle that eats hemlock woolly adelgid — to the fight.