Oldest Tree in Chicago Reaches End of Life Cycle, Slated to Come Down for Public Safety

As the oldest tree in Chicago, has reached the end of its life cycle, the said sentinel will be cut down for the sake of public safety.

From Friday to Sunday at the Lincoln Park Zoo, visitors paid their respects to a centuries-old oak tree that has reached the end of its life cycle.

Before the bur oak tree is taken down on Monday, the zoo encouraged people to write "thank-you" letters to it.

This was announced through local media outlets like KissFM Chicago.

Oldest Tree in Chicago

The tree, which is about 70 feet tall and is located across from the enclosure for white-cheeked gibbons, is thought to be between 250 and 300 years old and has come to the end of its life cycle.

Thought to be among Chicago's oldest trees, possibly even predating the city's founding in 1837, its age can only be determined by taking coring samples.

Maureen Leahy, the vice president of animal care and horticulture for the zoo, said that although they are heartbroken to see a part of Chicago history depart the zoo, they are driven to preserve its legacy by forming meaningful partnerships that will benefit both the community and the zoo.

The zoo organized several activities for Arbor Day last Friday, including leaf identification tests, tree ring counting games, and writing letters to the tree, among others.

Free tours of the arboretum-accredited zoo were also provided, and they were led by horticulture professionals.

End of Life Cycle

Last fall, Katrina Quint, the director of horticulture at the zoo, estimated that the bur oak was about 80% dead.

Given that it is close to a wide sidewalk, its removal is required.

According to Quint, bur oak trees are a native species of Illinois and can live up to 400 years if they are growing in a savannah environment.

The lifespan of this tree has been shortened, however, by urban pressure.

The age of this tree was determined by measuring its diameter at a height of four feet, while the diameter of this tree was 46 inches.

Quint claimed that taking a core sample of the tree was the only way to determine its true age.

At that point, professionals use a unique tool to drill into the tree and bring out a complete cross-section of the tree.

The exact age will then be determined by counting the rings.

Preserving a Legacy

The Morton Arboretum and the zoo collaborated to graft 36 of the tree's scions onto rootstock for propagation to preserve its genetics, ensuring that the tree's legacy would continue.

Additionally, the Illinois State Archaeological Survey will receive pieces of the tree to help with dendrological and climate research in Cook County as well as the Forest Preserve.

The extent of the tree's trunk degradation will, however, determine whether it can continue to exist in other ways, according to zoo leaders.

Slices of the tree will be dried, ground, and preserved by officials for use as memorials, educational resources, and play areas at the zoo.

According to zoo leaders, local woodworkers and craftsmen have shown interest in working with the tree's remnants to make other goods and artwork.

As noted in a previous statement by Quint, the tree is part of a cluster of bur oaks that have produced offspring.

Over time, one of those young trees might be moved into the bur oak's location.

Bur Oaks in Lincoln Park Zoo

Quint added that while the loss of one of the zoo's oldest trees is very sad, the team is pleased to note that there are several other bur oak trees that are quite large, sporting over 100 years of age in the zoo, Block Chicago Club reported.

The long-lived bur oak grows thick bark that can withstand the once-common prairie fires and has branches that spread widely.

Its large acorns, which can reach a length of 1.5 inches and have a fringed burry cup, are a vital source of food for numerous birds and small mammals.

The tree has large, green leaves with round lobes that turn amber in the fall.

The tree's bark stems, and foliage serve as shelter for a variety of insects, birds, and squirrels.

According to the Lincoln Park Zoo, there are 40 recorded bur oaks within its boundaries.