By Stephanie Schupska
University of
Georgia

The GPS signal bounced from earth to space to earth in a matter
of seconds. And when enough satellites lined up the
coordinates, David Berle had pinpointed another tree to add to
his inventory.

The horticulture professor with the University of Georgia
College of Agricultural and Environmental Sciences spent a
Maymester term teaching his students how to hunt trees and add
them to a geographic information systems database. And although
it was a class project, the study also helped Clarke County,
Ga., foresters.

“We mapped trees that already have significance,” Berle
said. “The county had all the trees inventoried, but didn’t
have a good map of them.”

The timing was close to perfect. During that early summer term,
a new Athens-Clarke County tree ordinance was finalized that
included a landmark tree inventory. It went into effect Sept.
1.

Many Georgia counties – including Fulton (Atlanta), Richmond
(Augusta), Thomas (Thomasville), Berrien (Nashville) and
Chatham (Savannah) – have similar ordinances.

The Athens-Clarke County ordinance calls for two full-time
foresters, as do others in the state. “This opens up a lot of
positions for students,” Berle said. “It’s a good link in
preparing students for the job market.

“I teach it as a chance to learn technology,” he said. “And
this technology has real world application.”

The yellow hand-held global positioning systems that his class
uses are accurate within one meter. The funds to purchase the
devices – which cost $5,000 each – came from a UGA Learning
Technologies Grant.

“It helps sometimes when you’re teaching to have something that
looks like a Game Boy,” he said in reference to the GPS. “One
of our long-term goals is to go online with this information,”
much like a person can go online, map out road directions and,
now, view the area’s geography. “It’s a lot of ‘wow, gee whiz’
practical stuff.”

It’s practical because mapping trees isn’t just about building
inventory. Realtors, planning committees and other
organizations throughout the state compare this information,
such as an area’s tree canopy, to the property value of a home.
Having that information readily available, and giving
significant trees “a unique point on the map,” would speed up
the process. Mapping landmark trees also helps contractors know
which trees to protect when they are developing land for
residential or commercial purposes, Berle said.

The class of eight students didn’t spend the three-week term
mapping every single tree in the county. Instead, they hunted
champion trees, historic trees and trees that have cultural
significance.

A champion tree is the “largest tree of a particular species …
it helps citizens in the county to keep looking for the next
big tree,” Berle said. Trees with historical significance
include those in a former slave cemetery that started in an
open field and over the centuries turned into a dense forest.
Culturally significant trees include the Moon Tree, a pine tree
whose seed was taken on an Apollo mission.

Once a tree has been pinpointed on a geographic information
systems map by several of the 23 American satellites orbiting
the earth, Berle checks an Internet site 24 hours later for
variances. The U.S. government put these safeguards in place to
deter others from using GPS technology against Americans.

Access to such satellite technology has only been available to
the public since the early 1990s. It was developed for defense
purposes in the 1970s. And now it’s being used by
horticulturists, foresters and students to keep an eye on trees.

(Stephanie Schupska is a news editor with the University of
Georgia College of Agricultural and Environmental Sciences.)