As fall break approaches, so does the peak of both the fall season and the changing leaves.

The Pennsylvania Department of Conservation and Natural Resources issues a regular fall foliage report that shows Greene County getting ready for the seasonal color. 

According to the 2024 Fall Foliage Report for week three at the DCNR website, Greene County remained in the “starting to change” range for the period of Oct. 10-16. The report showed neighboring Washington County in the same category. Neighboring Fayette County had advanced to the next stage of “approaching best color.”

According to Janet Paladino, the University’s Environmental Sustainability Coordinator, “The peak is usually in the middle of the month or a little bit earlier than the middle of the month, but really it depends.”

Paladino added, “Now is the time when they really start to change. We are having cool crisp nights for the next week or so, and that’s when the leaves say, ‘We’re going to change color,’ and that has to do with the chlorophylls, which affect the pigment of the leaves. After the chlorophylls die, that’s when the leaves begin to change color. They keep leaves green, reflecting green light.”

Different factors affect when the leaves fall, as well as their brilliance, according to Paladino, and the study of these phenomena is called phenology.

Paladino said that the three most important factors which affect leaves’ changes are “…temperature, precipitation, soil and moisture and the most important one is light.”

A fall standout on campus, according to Paladino, is the sugar maple, the leaves of which can turn anywhere from yellow to red. “The sugar maples are a very beautiful, very colorful tree,” she said. “They’re pretty resilient to these problems of climate change and lack of moisture, but there’s been studies done that say the leaves are dropping later and that the brilliancy of the leaves, depending on how much moisture you have or precipitation you have, might change.”

On the topic of colorful leaves, Paladino said, “One of my favorite trees on campus; there’s a tree called a ginkgo, and this ginkgo is in front of Miller Hall, and it’s one of the tallest trees on campus. This is an interesting tree because it was planted in the 1950s. If conditions are right, it will change into a brilliant yellow and fall in a span of two hours. If it’s too dry, the leaves will stay green and drop. It keeps its leaves on for as long as it possibly can.”

However, the University may not see the yellow leaves of the Miller Hall ginkgo this year. According to Paladino, the heat from the summer may cause the tree to drop its leaves without changing their color.

When a tree does succeed in changing its color however, the process is called senescence, according to Paladino, who said, “Senescence is programmed cell death. The trees senesce their leaves every year. It’s the scientific name for leaf drop.” 

She added that one of the reasons trees senesce their leaves is to avoid excess weight on their branches, particularly during snow or ice storms. This helps them avoid breakages.

Some trees can resist this process, though. “The wood on pine trees have evolved to be able to hold snow,” Paladino said. “Rarely pine trees are destroyed by snow.” She added that this is true for many evergreen trees, and not just the pines, which can be seen on campus.

Paladino urged students to stay in touch with nature this fall. “Just enjoy,” she said. “Make a connection with nature. This is a beautiful time of year, and some people forget that.”

The Yellow Jacket welcomes students to share their fall foliage photos for a chance at being published in a future article.