An orange-vested man marched along Old Archer Road. Diligently counting his paces, Ross Barreto stepped over a jumble of roots to photograph his subject: a beastly oak. The tree seemed to watch him unspool a sunny yellow measuring tape, as if waiting for his embrace.
The “mind-numbing” task went like this: snap a picture, reach around to record diameter, trek to another tree. Barreto, 24, a University of Florida graduate student in forest systems, tucked the tape into his tool belt and moved along.
He won’t stop until Gainesville’s millions of resident trees are counted and cataloged.
“It’s tedious,” he said. “But to me, it’s the highlight of my day.”
Beginning last summer, a crew of students and professors fanned out across the city for a project expected to be finished in 2026. It will yield a full inventory of Gainesville’s trees at eight or more inches in diameter and calculate what’s known as their ecological services, like utility savings from shade. UF Forest Systems Associate Professor Michael Andreu and Arboriculture Associate Professor Ryan Klein lead the study, emulating a similar project completed in 2016.
The idea is to help the city update its tree goals and better understand local needs and perceptions of plant life, Andreu said.
The 2016 inventory found that Gainesville had 47% canopy coverage – just shy of the city’s long-term target of 50%. The resulting shade saved residential homes an estimated $7.7 million in heating and cooling costs that year.
In comparison with similar urban forestry studies across the state, Tampa had only 32% tree cover. Orlando and Miami lagged behind at 22% and 21% respectively.
Nine years later, the new study will see how far Gainesville has come. It’s funded by the city’s tree mitigation fund, a pool of fees paid by developers who take out trees and their canopy. Though in the early stages, Andreu said the team has already noticed several areas with fewer trees than in 2016.
“We’ve been developing,” he said. “And we know when that happens, trees start disappearing.”
With most people in Florida and across the globe settling in cities, Andreu said humanity has become an “urban species.” A stronger alliance with trees could keep development “functional and livable and sustainable” in a warming world, he said.
While Barreto – the crew leader for a group of graduate students – measures and photographs in the field, Andreu and Klein run digital analyses of species adaptability, carbon storage, costs and more.
Cooler areas, happier people
Trees are Earth’s built-in air conditioners. Without their shade, heat is amplified in paved areas. Called the urban heat island effect, think of this swelter like bolting across hot asphalt in the summer. The blacktop can be roughly 40 to 60 degrees hotter than the air in direct sunlight, easily searing bare feet. But shade and transpiration, or evaporation from leaves, gives trees the ability to cool their surroundings.
On the east side of the city, Samuel Schatz pedals his bike, noting which roads need more shade as he glides along. Then, as Gainesville’s Urban Forestry Division program coordinator, he sends trees.
“Wherever you have trees that are providing a lot of shade, you’re going to have much cooler areas,” Schatz said. “Much happier people.”
He said the east side has been historically underserved and houses less canopy cover than the west side, thus the recent focus for plantings. City officials also respond to district requests. As a result, about 70% of Gainesville's tree mitigation fund has been directed to the east side for the past four years, with most sent to the northeastern portion of town in District 1, Schatz said.
Most municipalities have developed codes to regulate where and what kind of trees can be planted. As climate change brings stronger storms and extreme heat, Schatz said city codes need to add resilient species and remove those with temperature sensitivity and short lifespans.
Loblolly and slash pines, with their needle-like leaves and prickled cones, were the dominant species recorded in the 2016 inventory. The next most prevalent were laurel oaks, water oaks and red maple.
Laurel and water oaks were more common than live oaks. The former two species are narrower and survive only about 70 years. But their wizened counterparts have a several-hundred-year lifespan with more resistance to damage and decay.
Considering such factors is essential given the unpredictable climate future, Schatz said.
“Trees take years and years and years and years and years to grow,” he said. “It’s something you have to proactively think about ahead of time.”
Trees also have another gift: They trap excess carbon that would otherwise aggravate global warming. In 2016, the city found that its resident trees sequestered the equivalent annual carbon emissions of over 30,000 automobiles.
Yet, this “carbon capture” is on the decline globally. That’s one reason the UF team will reexamine Gainesville’s sequestration in the new study, said Klein, the second researcher leading the inventory.
“That shouldn’t necessarily decrease unless there’s a decrease in the health of the trees in an area,” Klein said. “But when you start talking about climate change, it’s very possible trees are going to become more stressed in the future… that could be an issue we run into down the road.”
Relief from the heat on a local level will still require mechanical air conditioning. But by planting more trees, Gainesville can reduce A/C use and the related carbon emissions, Klein said. And with lower emissions comes the possibility of a naturally cooler world.
Trees as "second-class citizens"
The turbulent state of home insurance also poses challenges for the tree canopy by requiring residents to cut branches that extend over their homes. Though the policies are well-intentioned, Klein said they can lead to greater tree instability, making trees even more likely to collapse during storms.
In the mayhem of hurricane preparation and rapid development, Klein said trees are to some extent treated as “second-class citizens.”
Micanopy resident Pierce Jones said nearby hickory trees left him concerned for the safety of his home, especially as branches began to grow closer.
“I got great shade,” he said. “But just the combination of hearing those hickory nuts fall on my metal roof and nervousness about storms, I took that tree out.”
As a retired UF professor, he also specializes in resource efficient communities, including the “spectrum” of ensuring tree security and reaping the benefits of their natural cooling properties. He said residents can have both by choosing sturdy species like magnolias or live oaks over cheaper alternatives.
In addition to building taller homes with reflective roofs, he said canopy coverage could be the difference between unbearable heat and a pleasant microclimate in the Sunshine State.
“Get more trees,” he said. “Get more shade.”
