Hemlock, Pennsylvania state tree, worth a special fight


Forestry scientists are engaged in a frustrating but important fight to save Pennsylvania’s state tree, the Eastern hemlock.

The hemlock woolly adelgid continues to lay siege to the commonwealth’s hemlocks, literally sucking the life out of the trees. The adelgid’s destructive effects wax and wane, but these damaging insects have taken an ever-deadlier toll in recent years. Pennsylvania Bureau of Forestry’s Forest Pest Management group is wise to pursue remedies to protect the 300,000 to 500,000 hemlocks within the Delaware Water Gap National Recreation Area.

More than principle is at stake in the battle to save the state tree. Property owners use hemlocks as landscape trees, but in the wild hemlocks commonly grow along steep slopes, shading rocky streams where trout thrive. Even in the dog days of summer, their dense shade creates a microclimate that keeps the swift-running water – and the air – deliciously cool. The Pocono Mountains have served as a mecca for trout fishermen for more than 100 years thanks in no small part to the canopy of deep-green hemlocks that stand vigil over the rushing streams.

When the adelgids suck their way through the trees, they weaken them. Especially heavy infestations can kill them. Sunshine reaches the forest floor and shines into these pristine waters, warming them. The result for Pocono trout streams is an ecological and aesthetic tragedy. Hemlocks form an important part of our region’s natural landscape. They deserve our vigilance.

Unfortunately it’s neither safe nor practical to spray insecticides over wide swaths of Pennsylvania’s hemlock forests. So the woolly adelgid has continued to make inroads, and Forestry scientists are working hard to study the pest and control it. They have introduced beetles to try to control the adelgid, but results have been disappointing. Recently student interns with the Student Conservation Association spent time with the Bureau injecting insecticide at the base of hemlock trees near Bushkill. Experts say unless they discover an effective treatment, as many as three-fourths of the park’s estimated 500,000 hemlocks will die over the next decade or so. Extend that to forests all across Pennsylvania, and imagine the devastation should the hemlocks disappear.

Individual property owners can help by being vigilant about their own hemlock trees, checking for infestation and treating them for the adelgid using approved methods such as insecticidal soap or horticultural oil.

Meanwhile scientists deserve support in their efforts to save these beautiful and useful trees on public lands. A healthy and diverse forest benefits everyone.

Copyright © 2009 Pocono Mountains Media Group

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Student Conservation Association