Preservation effort planned for trees threatened by insect at Flight 93 site
Over the next three years, National Park Service staff, partners and local contractors will work to preserve a grove of “witness trees” at the Flight 93 National Memorial, which are threatened by a nonnative, invasive insect.
When United Flight 93 barreled from the sky and crashed in a Somerset County field on Sept. 11, 2001, the aircraft plowed into a hemlock grove.
Referred to as witness trees, the grove contains the remains of the 40 passengers and crew, who died after terrorists wrested control of the plane. It crashed in Stonycreek Township instead of hitting a target in Washington.
Those trees are under attack by the hemlock woolly adelgid, park service officials said Wednesday. The staff discovered the insects' presence by their egg sacs, which resemble small tufts of cotton clinging to the underside of hemlock branches.
Infected hemlocks can change from a healthy green color to a grayish-green.
In a news release, officials said the park service and U.S. Forest Service scientists this week began a project to suppress the insect population's spread and preserve the hemlock grove.
Workers will treat 1,351 selected mature trees, along with many seedlings and saplings.
A combination of soil-buried tablets, soil injection, low-pressure tree injection, bark spray and horticultural oil spray are among treatment methods.
“We hope that these treatment methods will protect the hemlock trees and help us preserve the crash scene,” said Jeff Reinbold, superintendent of the National Parks of Western Pennsylvania.
The hemlock woolly adelgid was accidentally introduced to North America from Asia in 1924, according to the park service.
Its earliest record in Pennsylvania was in 1967, and it has become established in 19 eastern states from Georgia to Maine. As of 2007, 50 percent of the geographic range of eastern hemlock has been impacted by the insect, park officials said.
What remains of the grove in Stonycreek Township, which was damaged as the plane exploded, includes a gap where those trees were removed. A boulder at the base of the grove marks the impact site, considered a sacred burial ground.
When family members visit the memorial, and on annual 9/11 observations, they are escorted to the site to privately pay their respects.
Mary Pickels is a staff writer for Trib Total Media. She can be reached at 724-836-5401 or email@example.com.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.
Subscribe today! Click here for our subscription offers.