Science, color contrast behind beauty of fall foliage

Every year, as the month of October winds down, hues of golden yellow, orange and red foliage fill the campus, giving the university an aesthetic autumn backdrop of Newark’s fall at its prime. Though student observers note the natural beauty autumn has to offer, professor John Frett, director of the university’s Botanic Gardens, says these leaves do not change just to “look good.”

Frett says the process of autumn leaves exposing their various hues primarily involves chlorophyll, a pigment found in leaves. As the days grow shorter and the nights grow longer, chlorophyll production slows down, which begins to strip the leaves of their green color. This process is what first brings out the yellows, which Frett says is the most predominant color of fall foliage.

“Trees salvage nutrients and it begins to leave yellow [pigments],” Frett says. “Everything first turns yellow.”

As chlorophyll breaks down, two other pigments, carotenoids, which produce yellows and oranges, and anthocyanins, which produce reds, begin to maintain a presence in leaves, according to the Department of Agriculture.

Frett says warm days and cooler nights are the most ideal for this process to produce the most vibrant colors.

Though all trees undergo this process, not all trees are created equal, Frett says. Certain trees provide different hues and shades for onlookers. He says there is “tremendous diversity” of sweet gums, “brilliant scarlets” of black gums and “bright reds” of red maples.

Frett says while certain trees primarily feature certain colors, variation in colors provides contrast that is quintessential to a proper autumn experience.

“Changes in color are what appeals to people,” Frett says. “Having one color is like taking a canvas and just painting it bright orange—you have to have contrast.”

Frett says that while New England’s foliage does not change faster or for a longer duration than Newark’s fall, its contrast of leaves is what makes New England’s autumn more striking. The evergreen leaves provide an opposing green backdrop to the orange, yellow and red colors presented by the other trees, which is naturally appealing to onlookers.

Senior Victoria Cosgrove, who is originally from Glastonbury, Conn., says although fall in Glastonbury is beautiful, Newark’s fall still has much to offer. She says she especially enjoys the foliage around White Clay Creek State Park and the trees on The North Green around Gore Hall.

“It’s nice to feel the crisp air, look around and see trees,” Cosgrove says. “It’s much more enjoyable with the foliage.”

She says one advantage of living in Connecticut was that it was more wooded than Newark, which made fall very distinct.  
Cathleen Grimes, president of Students for the Environment, says Newark’s weather is at its peak when it is shifting from summer to fall. With this shift brings Grimes’ favorite aspects of fall—the crisp autumn air, color variations in leaves and sweaters.

“For me, fall signifies a changing in season,” Grimes says. “It’s one of the best parts of living in the Northeast.”  
Though onlookers often revel in autumn’s beauty, many questions are raised about what to do with leaves once they have fallen. According to the Environmental Protection Agency, leaf burning, a practice previously used by homeowners throughout the country, often leads to health problems, air pollution and fire hazards. In the state of Delaware, the practice of burning leaves has been banned since 1995, as the ban reads it is “important to protect people, animals and plants from harmful chemicals that are produced by open burning.”

In an attempt to be sustainable, the Delaware Solid Waste Authority also has a yard waste recycling program, in which residents can drop off their yard wastes, which are then recycled.

The university also recycles its leaves, according to Frett. Frett says the natural leaf-dropping process is important and that because leaves have nutrients, it’s important to let them decompose naturally in a compost pile. Many leaves on campus are taken to compost piles, some of those leaves being used to provide nutrients to plants in the Botanic Gardens.

“Burning leaves wastes good resources,” Frett says. “It removes substantial amounts of nutrients that would end up being replaced by fertilizers.”

Though fall has much to offer aesthetically, Frett says each season provides us with different qualities, making it impossible for him to pick a favorite season.

“Every season has a unique quality plant-wise,” Frett says. “There’s always something going on.”