Mindful Awareness of Shifting Baselines
By Judy Yi, Director of Education, Trees Atlanta
Trees Atlanta and our volunteers have planted over 113,000 trees; most of them are about six feet tall when they were planted. They’ll grow and stretch their limbs into broad canopies. Compared to some of the grand old trees standing guard in our Atlanta neighborhoods, these new trees look pretty small.

Judy Yi, Director of Education, Trees Atlanta
What if there was a different scale? Could you imagine our grand old trees looking puny next to even taller, larger giants?
There was a time not too long ago, when trees in Georgia were as big as those shown in the historical photograph below. Before the impact of massive logging and chestnut blight of the early 20th century, these giants were common throughout the Piedmont region. It’s said a squirrel could jump through the chestnut canopy from Georgia to Maine and never touch the ground.
Our perspective of what is common is relative to what we know.
Having never experienced a landscape of chestnut giants, we see the oaks and pecan trees in Atlanta as the new giants. For some children in the Metro-Atlanta area, it’s not peculiar for them to have no trees in their yard or even at the neighborhood playground. They may see only smaller trees planted along the street.

Lumberjacks in North Carolina around 1910 are dwarfed by old-growth chestnut trees (photo credit: Forest History Society, Durham, North Carolina).
There’s a bittersweet nostalgia to this. It’s similar when I see children who delight to see a blink of a firefly in the fading light of dusk. To these children, seeing a few fireflies dancing in the dark is magical. Today they see two, and one day if they see none, will they notice and ponder the change? I remember fields of hundreds of glowing lightning bugs – if not thousands – twinkling in summer nights. This is my baseline; there may have once been millions in a field. It’s equally as hard to consider that the estimate of American chestnuts lost in our Piedmont region may have been over four billion trees.
These types of transitions happen over time, and they are illustrations of the “Shifting Baseline Syndrome” (phrase coined by scientist, Daniel Pauly). It describes a failure to accurately assess change when new reference points are accepted as the norm. Each successive generation of change moves the baseline.
Through my work in the education programs at Trees Atlanta, I see first-hand signs of shifting baselines in our relationships with trees and nature. Some of the students we teach in our in-school Urban TreeTracker program are wary of walking off the sidewalk into the woods. Not infrequently, adults who join us on a tour of the Atlanta BeltLine Arboretum or on a city Tree Walk see the natural succession of native wildflowers and perennial plantings as unkempt. These responses are reflections of our shifting baselines, gradual changes as we become more acclimated to a cultivated, man-made environment rather than a natural ecosystem.
Trees Atlanta is working to shift the baseline in our favor. We plant trees near the grand old giants, as well as places where trees are currently absent. Along the Atlanta BeltLine, Trees Atlanta’s work in the Arboretum intentionally includes native plants that improve the soil condition and create a welcoming pollinator corridor. The amazing show of colorful blooms and changing foliage through the seasons is a demonstration of how a Piedmont prairie would repair itself in nature. These moments and experiences help to push the shifting norms toward greater awareness and a reconnection to natural environments – particularly in our urban communities.
One clear evidence of the City of Atlanta’s commitment to protecting our “city in the forest” is the commission of an ongoing study of the actual state of the tree canopy in Atlanta. In collaboration with the Center for GIS at Georgia Tech, the city published the first “baseline” in 2015. Analysis of a massive dataset of infrared satellite scans of Atlanta for 2008 shows our canopy coverage to be 47.9% of the city’s total land area. The city’s goal is to ensure no net canopy loss as set by this 2008 baseline – a city average of vastly diverse urban landscapes.
Trees Atlanta is also applying this information to make the data easily available via an online interactive tool called the Atlanta Canopy Tool.

Atlanta Canopy Tool
This visual resource allows anyone to objectively understand the current state of canopy coverage by council district, NPU, neighborhood, or local street (limited to the City of Atlanta boundaries). Some neighborhoods measure over 80% canopy coverage, while Downtown Atlanta is lowest at 3%. We’re excited that the City of Atlanta and Georgia Tech are already working on analyzing satellite data of the 2014 state of the canopy. Trees Atlanta’s Canopy Conversations series of community meetings are offered to help residents have intentional conversations about the baselines, shifts, and actions we can take to make the changes important to us.
Our work to protect and improve the urban forest is more important than ever. Where once squirrels traversed the land on tree tops without touching the ground, our new baseline could become tree-lined streets where pedestrians could traverse the city without ever leaving the shade of a tree!