The trees that make maple syrup will struggle to survive climate change, a new study reveals.
Researchers had thought that pollution from cars, factories, and agriculture might buffer sugar maples against an increasingly warm and dry climate by supplying soils with fertilizing nitrogen.
The new analysis, which examined 20 years of tree and soil data in four Michigan locations, finds that extra boost of nitrogen won’t be enough. They ran two climate change scenarios specific to the region.
In the second, more extreme case based on current emission trends continuing into the future, temperature would rise by more than 5°C, and 40% less rain would fall in the summer.
In both scenarios, the trees didn’t grow as much as they do now, but tree growth in the second scenario nearly stopped, even with a bump from extra nitrogen.
The researchers say sugar maples will eventually disappear if conditions from the second case hold true.