Trees growing in forests in the eastern United States have proved able to adapt to the local climate, a new study of 14 tree species has found. However, most species thrived in cooler, wetter years.
In the eastern United States, adult trees can adapt and acclimatize to the local climate, a new study has found.
Using data from the tree rings of 14 of the most common species, including sugar maple, red spruce and white ash, the scientists analysed how individual trees had responded to the climate during a 40-year period.
“There is evidence of pervasive local adaptation,” confirmed research leader Charles Canham from the Cary Institute of Ecosystem Studies in a statement.
Cores were taken from trees at more than 7,000 plots in six New England states, as well as Pennsylvania, West Virginia and Ohio.
The team tested alternate models of how much trees grew from year to year to determine whether growth was affected by absolute climate values or better predicted by deviation from the long-term mean climate at a location.
Canham explained: “Trees responded to climate based on deviation from the long-term mean conditions in the location where they were growing. For all 14 species, models that used deviation from the local, long-term mean were superior, with all 14 species showing strong adaptation or acclimation to local climate.”
For most species, growth was highest in years that were cooler and wetter than the long-term average at a site.
While adaptation based on genetic diversity within a population could render trees more sensitive to climate change than expected, acclimatisation arising from phenotypic plasticity, or an ability to adapt to the local environment, could make them more resilient.
The bottom line, said Canham, is that “trees are cleverer than we give them credit for – but we don’t know how they are pulling it off or if they can keep pace with climate change.”
Photo credit: Superior National Forest/ CC BY 2.0