Staff Writer

Written in 1913 and first published a year later, that’s poet Joyce Kilmer’s most famous work and certainly expresses his regard for a particular type of flora.

City of Jacksonville Urban Forester Don Robertson speaks in more technical terms but has an equally intense appreciation for trees and what they contribute to the urban landscape and environment. He has a degree in arboriculture and park management. For the past 12 years Robertson has been the person responsible for the well-being of Jacksonville’s trees living on right-of-ways or other City property.

“Twenty percent of the urban forest is under control of the City,” he said. “But Downtown is the highest density in terms of the City’s control.”

Robertson can quote a lot of statistics about the value of trees. He said without trees, Downtown would be what he called a “heat island,” meaning temperatures would soar any time the sun is shining. Trees also absorb carbon dioxide and release oxygen, so an environment with high levels of vehicle exhaust is made much healthier by having trees in the landscape.

“Trees can also reduce crime because they create a more pleasant environment and cause people to take ownership. That puts more eyes on the street,” said Robertson.

All that being said, he added that the Downtown environment puts its almost 1,000 trees under a lot of pressure.

“The soil is lacking in nutrients and since trees are planted in pits Downtown, the amount of water available is limited. It’s probably the toughest environment for a tree,” said Robertson.

Due to the stress, trees planted Downtown don’t live as long as they would in the suburbs and it’s a constant job to maintain the tree canopy.

When choosing trees for the Downtown streetscape one of the most important considerations is the species. Trees that develop very shallow roots can buckle the sidewalk, for instance. Trees that grow low branches can conflict with traffic like trucks and buses. Narrow streets also call for trees that grow with more of a vertical than overhanging habit, one of the reasons palm trees are common.

“We also plant Florida-friendly trees. We don’t use exotic or invasive varieties,” said Robertson. It’s important to avoid what he called “monoculture” and choose a variety of tree species in order to prevent substantial losses due to diseases that usually affect some species more than others.

The urban forester also knows the history behind many of Downtown’s trees. While most of the specimens in Hemming Plaza are laurel oaks, the 20-foot-tall “Andrew Jackson southern magnolia” growing near the corner of Hogan and Monroe streets is special. It’s about 20 years old and there’s an interesting story about its ancestry.

“On the back of the $20 bill is a picture of the White House. That magnolia in the plaza was grown from a seed taken from the tree on the left in the picture, so it’s a direct descendant of that tree,” said Robertson.

mmarbut@baileypub.com

356-2466