LAKE GEORGE — The state Department of Environmental Conservation and private organizations dedicated to eradicating invasive species will use satellite images to try to to detect hemlock wooly adelgid sooner, after a large infestation of the tree-killing insect was found on the eastern shores of Lake George.
The goal of the Save Our Lake George Hemlocks Initiative is to identify future infestations through infrared images before a decline in tree health is visible to the naked eye, so threats to the hemlock population can be identified and treated early.
Satellite images will also allow a large area to be surveyed for potential trouble spots, so that field crews can be efficiently deployed to assess possible infestations.
“With approximately 80% of the forested area in the Lake George watershed made up of eastern hemlock, the time for action is now,” said Eric Siy, executive director of The Fund for Lake George. “Our consortium has developed an aggressive early detection and rapid response program to help seek and stop the spread of HWA.”
The hemlock wooly adelgid, which is already found in much of the Capital Region, was first detected in August at the Glen Island Campground. An investigation then determined that HWA had spread — without previous detection — to nearly 250 acres of state-managed land on the east side of the lake, in the towns of Fort Ann and Dresden. It was also previously detected in 2017 on Prospect Mountain in Lake George, but only three trees were impacted.
“The infestation is larger than we had hoped, and older than we had hoped,” said Rob Davies, DEC’s director of the bureau of land and forests. He estimated the infestation had been spreading undetected for five years or more.
The new initiative will augment work being done by DEC, Cornell’s New York State Hemlock Initiative, and others to confirm the extent of and treat the current infestation.
Partners in the initative include the Fund for Lake George, the Adirondack Park Invasive Plant Program, the Lake George Land Conservancy, City University of New York’s Advanced Science Research Center, the U.S. Forest Service, Adirondack Research, and others. A total of $125,000 is being committed to the project, which may become a model for the Adirondack Park and potentially, the entire state.
“Hemlocks are a critical component of the ecosystem in the Lake George watershed and HWA is a threat to the health and stability of the region’s hemlock forests,” said DEC Commissioner Basil Seggos. “Early detection of invasive species is an important tool when responding to these threats and protecting New York’s treasured natural resources.”
Until now, identification of a HWA infestation around Lake George depended on its discovery by someone on the ground who happened to spot the tell-tale signs on the exterior of the tree: white wooly masses on the underside of branches, gray-tinted needles, and needle loss and branch dieback.
Using advanced remote sensing technologies and computer modeling, HWA damage can be detected before significant defoliation or mortality occurs, experts say. Trees can be treated if the problem is caught early enough.
Satellites that produce aerial photographic images also capture infrared or near-infrared data that can reveal the level of photosynthetic activity taking place within a forest stand. The level of photosynthetic activity can provide evidence of declining forest health before that decline is apparent to the naked eye.
Later this month, the initiative’s experts will begin reviewing five years of remote sensing imagery and data for an approximately 4,400-square-mile region, from the northern portion of the Lake George watershed south to Troy. Changes over time can be used to determine areas that ground crews should check. The pilot program is expected to last until next spring.
The hemlock woolly adelgid is a small, aphid-like insect that damages hemlocks by inserting its piercing-sucking mouthparts into a tree’s twig. As adelgid populations grow and more insects feed on a single tree, the flows of water and nutrients are impacted,eventually resulting in tree death.