When Kim Steiner created an ash plantation on the edge of Penn State's University Park campus in 1978, few Americans thought about "climate change," no one had heard of the emerald ash borer, and the Yankees beat the Dodgers in the World Series, swinging primarily bats made from ash.
For ash trees, those surely were the good old days.
Steiner, professor of forest biology in Penn State's College of Agricultural Sciences, who is also now director of The Arboretum at Penn State, had collected seeds from wild green ash trees in 27 states and Canadian provinces in the fall of 1975. He grew the seedlings for two years before methodically planting 2,100 of them, all 12 feet apart, in a seven-acre plot.
Steiner was conducting a provenance trial, also called a common-garden test — basically moving trees that had evolved in different climates to one location and carefully monitoring their growth and other characteristics. The goal was to understand how species adapt to their environments. Fortunately, in the last few decades, the plantation was maintained because of the opportunity it provided to study the effects of climate change on trees.
"I knew that I couldn't get everything I wanted when I sent out two graduate students with funding on a two-week swing through the Midwest and South to collect seeds in wild populations of green ash," he said. "So I also mailed hundreds of letters to federal and state forestry employees, park supervisors, fellow scientists — anyone I could get a name and address for — asking for help in collecting ash seeds from local wild populations."
It turns out that the little-known ash plantation off of Porter Road near the University's Swine Research Facility — the largest collection of green ash germplasm in one location in the world — likely will play a significant role in saving the species, which is being decimated by an insect from Asia.
The emerald ash borer, often referred to as EAB, is a half-inch long, metallic green, wood-boring invasive insect that feeds exclusively on ash trees. EAB larvae feed under the trees' bark, and they eventually girdle and kill trees within four years of infestation. They first were identified in North America in Michigan in 2002 and showed up in Pennsylvania in 2007.
The borers have killed tens of millions of ash trees across North America, and their devastation is so complete that forest scientists worry they will essentially wipe out our native ash species, all of which appear to be susceptible. Highways through much of the mid-Atlantic and Midwest regions are now lined with the skeletons of dead ash trees.
In Penn State's ash plantation, in forests across Pennsylvania, and in a growing portion of the East, the emerald ash borer is killing nearly all ash trees. The relatively few that survive or escape — "lingering ash trees," as scientists are calling them — may hold the key to rescuing the species, and Penn State tree geneticists and other forest scientists are focusing on them.