UNIVERSITY PARK, Pa. -- For generations, nearly every image made of Penn State’s iconic Old Main building -- paintings, sketches, photographs -- has included the two majestic elm trees that grace its front corners. Now elm yellows, a disease that has already claimed many American elms on the University Park campus, has so infected one of the trees that it must be removed.
The University's Office of Physical Plant has scheduled the removal for the week of Spring Break, weather permitting, when the majority of the student and faculty population takes off for a much-needed breather from the semester. Fewer people on campus means that OPP’s crews will be able to carry out the complicated procedure quickly and in a safe manner, said Jeff Dice, supervisor of grounds maintenance.
Dice explained that swift removal of the dying tree is necessary to slow the spread of the epidemic. The elm’s infection was confirmed by Penn State’s Department of Plant Pathology and corroborated by the University Tree Commission. He added that University arborists have been able to impede the disease’s progress across campus, but not to stop it.
“We're talking about a disease with no known cure that caused spectacular regional outbreaks,” said Dice. “Penn State and the surrounding communities -- we're all fighting the same problem. There are a few trees that haven’t contracted the disease yet. It's been a difficult situation for everyone involved. Our efforts have been successful in slowing it down, but that’s all."
Elm yellows is a bacteria-like organism, spread by tiny insects called leafhoppers, which affects the inner bark that carries the nutrients to all parts of the tree, including the root cells. An infected tree cannot receive adequate nourishment and, by the end of summer, its leaves turn yellow and it dies. Elm yellows spreads rapidly from tree to tree and has devastated elms in localized pockets throughout the U.S. The University maintains a website with news and information about ongoing efforts against elm yellows.
"When you add Dutch elm disease into the mix," said Dice, "the combination has resulted in substantial mortality in the elm tree population of the Centre Region. Our plan now is to try to manage the remaining trees to prolong their lives, and also to focus on cooperative efforts to replant the historic core of campus in a more sustainable way."
Dutch elm disease is a fungal disease spread by the elm bark beetle, and is unrelated to elm yellows. Dutch elm has affected native populations of American elms for decades. Though Penn State arborists have effectively combated Dutch elm for over 50 years, recently the threat has increased because trees that have been infected by elm yellows provide ideal conditions for elm bark beetles to spread Dutch elm disease.
Since the onset of elm yellows on campus in 2007, 76 trees have been lost. Add to these the number of trees killed prior and since by Dutch elm, and out of approximately 290 trees, about 100 remain.
In order to avoid a repeat situation in the future, said Dice, the University does not plan to replace the elms with more of the same. Last spring, workers planted more than two dozen trees on the campus' historic core, including an array of shade specimens that grow in Pennsylvania, such as coffee trees, plane trees, bur oaks, white oaks, lindens and zelkovas. Planting different types of trees will guard against a future large-scale loss to disease.
“It’s tragic that we're losing these trees that have been with us for so long,” he said, “but if we plant the same species, the same thing could happen again. The key difference this time is to diversify -- to plant a variety of species to insulate us from potential diseases and insect attacks that we can’t predict.” That way, he explained, a new problem may only affect a fraction of the whole population.
Is the same fate in store for the remaining half of Old Main's matched set? Plans are being formulated for the eventual re-landscaping of the building's façade once both trees are gone. “There’s no evidence at this time that would require us to take down the remaining elm, but with proper care and attention we hope it will live for many years,” said Dice.
In 1933, the University planted a pair of American elms on either side of the entrance of the new Old Main, built just a few years prior in 1929. The new building replaced the original Old Main, which had deteriorated because of age to the point that renovation was not feasible.
Two sizable young specimens were chosen from among the campus’ existing American elm population. The University began planting elm trees in 1890 and continued throughout the years, with the most recent plantings dating from 1996 and 2006.
“These trees have witnessed a lot of Penn State history,” said Michael Bezilla, a University historian. “They have attended every kind of event on Old Main lawn -- student protests, candlelight vigils, public addresses by President George H.W. Bush and then-future President Barack Obama, Gentle Thursday, celebrations of the arts -- the list is really endless. Eight Penn State presidents, looking out from their corner office on Old Main’s second floor, have seen up close how that southwest elm tree has matured and flourished.
"And we can never know the countless personal events they’ve witnessed -- the individual triumphs and tragedies and joys and sorrows of the tens of thousands of students and faculty and others who have walked under their branches,” he added.
Dice noted that assistance has come from several areas of the University to help with tree replacement, no small financial matter. Among these efforts are the Historic Tree Endowment, the gift of the class of 1996, which supports maintenance and replacement of campus elms. “The forethought and generosity of those seniors is now helping us through an extremely difficult time,” he said.
In addition, wood from the removed trees is salvaged and converted into an exclusive line of hand-crafted furniture -- the Penn State Elms Collection -- a partnership between the Penn State Alumni Association and the Office of Physical Plant. A portion of proceeds goes to the Historic Tree Endowment.
“I remember sitting under those trees as a student in the '70s, listening to steel drums at the Arts Festival,” said Dice. “It’s always impressed me that people still recall elms that were removed many years ago, and they’ll remember the matching elms, too. They are part of the permanent landscape in the memory of thousands of Penn Staters.
“It's very sad that we have to do this. But with help we’ll plant a new landscape for the future, one that will witness years of Penn State history to come.”
To watch a video with more information and background on the elm, go to http://www.youtube.com/user/PennState?feature=watch#p/u/6/BRrYJfeC7C4. Go to http://live.psu.edu/flickrset/72157629127017528 to view past and present photos of the elm.