2019-01-12 / Front Page

Can our hemlocks be saved?

There has been at least one upside the wet summer and autumn of 2018. And a certain group of people would like nothing better than a brutally cold winter to follow in suit.

The beneficiary, they say, is the cherished eastern hemlock, Pennsylvania’s state tree. Its storied history and timeless environmental significance and aesthetic appeal in the state’s northcentral region is being threated by a deadly invasive species that has the potential to eliminate it from the landscape.

But just when the march of the hemlock woolly adelgid was gaining strength, its forces were knocked for a loop by this year’s heavy precipitation.

If the region sees extended periods of freezing temperatures – the colder, the better – that insect army will suffer further casualties.

Well aware of the fact that the adelgid army has countless recruits waiting in the wings, hemlock defenders are fighting back. A Potter/Tioga county coalition is in the front lines.

Pine Creek Watershed Council has developed a strategic plan to turn back the aphid-like insect that feeds exclusively on hemlocks and can kill a tree within four to 15 years.

Goal of the Headwater Hemlock Plan is to guide the planting of supplemental hemlocks or similar species as a buffer on both public and private lands. It will determine priority planting locations based on stream classification, level of infestation, and forest stand characteristics and location

There is some disagreement as to which species should be planted, an issue that has been under discussion within the Pa. Dept. of Conservation and Natural Resources, which manages state forest and park land.

“Hemlocks are a foundation species, meaning they serve as the foundation for an entire ecological community,” explained council spokesman Jim Weaver. “Not only is the loss of the aesthetic value of our area a threat to tourism, an increase in ambient temperatures of our headwater streams due to climate-related impacts will affect the quality of the aquatic resources in the region.”

He pointed out that hemlocks provide a thick canopy that naturally cools waterways.

Called the “redwood of the east,” eastern hemlocks can grow more than 150 feet tall on trunks measuring six feet in diameter. Some of the region’s hemlocks are hundreds of years old.

Adelgid infestations have been ravaging the species. In some areas, infested trees have begun to die. The insect is easily dispersed by birds and wind, but travels most rapidly as a hitchhiker on infested horticultural material.

The hemlock woolly adelgid covers itself with a white, waxy “wool” which acts as a protective coating. Adelgid infestations are easily recognizable by the appearance of tiny “cotton balls” at the base of hemlock needles. The “wool” is most conspicuous on the undersides of branches from fall through spring.

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