Dennis Nola sees the oak trees that tower over McKeldin Mall as cathedral-like. The willow oaks planted in 1941 line the green space, their branches curved toward the sky.

“You’re outdoors but you’re indoors,” said Nola, the assistant director and coordinator of the undergraduate landscape architecture program. “Our alumni say this is their No. 1 memory; they remember the oaks on the mall. Countless people walk up and down through these trees. Some people fall in love here.”

In the spirit of appreciation of the University of Maryland’s trees, a crowd of about 20 gathered to watch university Arboretum and Botanical Garden staff celebrate this state’s Arbor Day Wednesday by planting a new oak tree in front of Symons Hall.

Officials, including Provost Mary Ann Rankin, agriculture and natural resources Dean Cheng-i Wei and College Park Mayor Andy Fellows, shoveled dirt to commemorate the new tree. Afterward, attendees joined in the digging, as did a few students walking by.

The new tree, brought from a nursery in Laytonsville, replaces an older oak that stood in the same spot but died this past fall, said university arboretum volunteer coordinator Carin Celebuski. While the new tree is 10 years old and about 15 feet tall now, she said, it will quickly grow to about 100 feet.

The old tree died from root damage caused by the heavy foot traffic, Celebuski said. To help prevent the same damage to the new trees, the arboretum officials fluffed out the soil and discouraged students from walking across the roots.

Beyond aesthetics, the trees provide shade and wildlife habitats and improve the environment, said Nola, who also gave a short speech before the ceremonial digging.

“We leave a legacy when we plant for future generations,” Nola said. “It helps us to understand the nature of the space and why this space is so instrumental and so important, and it gives us a history and a culture.”

The philosophy behind Arbor Day is similar to a Chinese philosophy, Wei said. When we plant trees, we do so for future generations to enjoy, not ourselves.

“I know some of the trees, they have disease, they need to be removed,” he said. “But it is so good to see it being replaced. This place, a lot of times, my wife and myself we walk here.”

Facilities Management and landscape officials commonly replace trees in the way of construction or dying trees like the oak, university arborist Richard Jones said. This was done this semester with trees near Marie Mount Hall.

As the growing season begins, Jones said they will look into replacing trees removed for construction near the Pocomoke Building and the Landmark apartments, as well as trees damaged by snowstorms. They will also be researching and treating trees to stop damage caused by invasive emerald ash borer beetles.

Recent problems with tree preservation in College Park stress the importance of the state Arbor Day even more, Fellows said. Many citizens are angry at electricity company Pepco for cutting down trees near power lines, and construction crews needed to cut down some trees to build a new Whole Foods Market in Riverdale Park, he said.

“There are health effects, but there is also just a normal appreciation of trees,” Fellows said. “People really love trees. They are so important for our immediate community and here in College Park or on campus, but also in the county and the United States.”