If Fall Disappears, How Can We Respond?
By Alex Beasley, Donor and Public Relations Manager, ISA Certified Arborist, Trees Atlanta
Atlanta’s summers are becoming hotter, drier, and longer. This is the new norm. Much of the world has undergone ‘climate change-induced seasonal creep,’ meaning fall arrives later and spring arrives earlier each year. As the tropics expand by up to .2 degrees latitude yearly, many areas of the world are losing fall and spring altogether. According to the National Oceanographic and Atmospheric Administration (NOAA), 18 of the last 19 years have been the planet’s hottest in recorded history. Our climate is changing. How do we respond?
There are three steps we can take immediately to cope with climate change:
– Review your tree selection. Selecting the right tree in the right place is crucial. As hardiness zones, or regional zones of climate shift northward, some of our most popular trees may no longer be the best choice.
Per a Georgia Tech study, 36% of Atlanta’s native tree species are diminishing due to climate change. Popular species like sugar maple, dogwood, and redbud cannot withstand prolonged heat and little frost-time, thus, they should now be planted sparingly. The simplest solution is to select species similar to those in decline. For example, you might choose a two-winged silverbell as a suitable replacement for dogwood. It’s also possible to source the same species with a stronger genotype, a term used to describe an organism’s complete genetic makeup. Southern-sourced genotypes can often endure drought and higher temperatures more successfully than those specifically native to Atlanta. Plant selection must be considered carefully as non-natives have the potential to cause severe damage to our forest ecology.
-Modify your planting and tree care habits. Even with proper tree selection, long-term care must also be reassessed if trees are expected to thrive in urban areas. Timing is key. Through an analysis of 35 years of urban forestry data, Trees Atlanta has concluded that trees have higher survival rates when planted in consistently low temperatures as they approach or reach dormancy. A two-inch-thick ring of mulch promotes water retention and uncompacted soil while helping eliminate competition from weeds. Changing up your watering schedule can also make a huge difference. Ideally, water should be applied early in the morning or after sunset to avoid evaporation. Less frequent drenchings are drastically more beneficial when compared to numerous, light waterings. The deeper water permeates into the soil, the deeper and more stable a root network forms.
-Advocate for a better Tree Protection Ordinance. Improvements to the Tree Protection Ordinance are necessary to allow trees to thrive in, shade, and cool Atlanta’s vast impervious surface. Through shade and evapotranspiration, canopy trees reduce peak summer temperatures by up to 9°F. When strategically planted, trees combat city-wide heat island effect created by surface lots. In parking lots, trees are rarely given adequate soil volume to even survive more than a few years. The obvious solution to increasing parking lot trees’ soil volume is to plan and construct ample sized planting beds. In post-construction areas or where parking is at a premium, it’s important to consider technologies like permeable pavement and silva cells, modular underground blocks that provide aboveground support, abundant healthy soil, and adequate space for roots to spread.
Change can feel overwhelming, but you can make a difference. Individuals can have a tremendous impact by protecting existing trees and planting more trees on their properties. Trees Atlanta’s Shade Tree Program provides and plants FREE shade trees to residents of Atlanta, Chamblee, Brookhaven, and Sandy Springs. We each have the power to transform our immediate surroundings. The more people who decide to act on this, the more that these changes transform regional and worldwide norms.