See elsewhere on this page – another round of ice storms is hitting the Upper Midwest this week, following similar events from last year.
Extreme events and changes in seasons and hydrology are provoking concerns about the composition of forests, how they may be changing, and whether humans can mitigate or assist in adaptations.
As humans continue to heat the planet with greenhouse gases, potentially locking the Earth into a “hothouse” trajectory, according to new research, scientists worry that nature won’t be able to keep up with climate change.
“Forests have migrated and adapted to long-term changes in climate over thousands to millions of years; however, natural migration rates and adaptive responses of tree populations cannot match the rapid pace of current climate change,” according to a U.S. Forest Service study published in 2024. Relying on locally sourced trees for planting “may no longer be adequate.”
In Louisville, assisted migration involves planting tree species native to the area, such as the mighty bur oak, which can grow to over 100 feet tall, but sourcing them from further south and west in their North American range. Some species are different there, more suited to a hotter and harsher environment.
Assisted migration in Louisville can also mean planting tree species that are not native locally, such as the smaller but beautiful Lacey oak, with its delicate bluish-green foliage, from seed sources in Texas.
In either example, the idea is that these Southern-sourced trees from hundreds of miles away are likely to be better suited to the climate conditions anticipated in Louisville’s Ohio River Valley in 50 to 100 years.
Experts have said that Louisville by 2100 could be much more like today’s northeast Texas.
Sixty years out, average summer temperatures in Louisville could be nearly 8 degrees warmer, the New Jersey-based nonprofit science and communication group Climate Central has projected. In such a climate, trees will be increasingly important for the many ways they benefit communities, including shade, said Cindi Sullivan, the executive director of TreesLouisville.
“One of our adages is, it’s not just about the trees, it’s about the people and improving the quality of life and the health of this community,” she said.