Every year, thousands of tourists flock to New England to catch the iconic changing of the seasons, complete with pumpkin picking, apple cider sipping, and the perfect Instagram moments. Estimated by the U.S. Forest Service to bring in $8 billion in tourism revenue annually, autumn New England is a staple of the East Coast. But while residents and tourists enjoy the yearly spectacle, many scientists worry about our forests’ future.
With 2023 being the warmest October on record and October 2024 on track to rank among the driest in New England, environmental scientists are already seeing the effect of the changing leaves. This transition between summer and winter marks the final stage of the leaves’ life, known as leaf senescence.
Typically, earlier sunsets in August and September bring cooler evening temperatures, signaling to deciduous trees—trees that lose their leaves—to cut chlorophyll production. However, as warmer temperatures encroach further into these transition months, the trees are not prompted to begin senescence until much later.
Chlorophyll is the green pigment that absorbs sunlight through photosynthesis and gives trees their verdant hue. When trees feel the drop in temperature and cut chlorophyll, they leave behind the blazing reds, oranges, and yellows of autumn. Red anthocyanins are particularly found in red and sugar maples and help fend off the cold for a little while longer.
Weather extremes also have the potential to affect leaf coloration. Droughts can lead to less vibrancy, and cause leaves to fall earlier due to physiological stress, but extreme rainfall can be just as detrimental, putting equal stress on trees. For instance, in 2023, fall foliage was dampened in the wake of an El Niño in the Pacific Ocean.
These extreme weather conditions can also lead to other dangers for trees; in 2022, extreme rainfall and a wet season led to an outbreak of leaf fungus, which was disastrous for the sugar maple trees in New England. In addition, Ash Borers, a pest notorious for decimating ash tree populations, have significantly benefited from global warming, now estimated to wipe out 95% of ash trees in New England over the next 20-30 years. As the once frigid winters that would have normally culled these insects have steadily warmed, these once manageable fiends are now a significant threat.
“You need a Goldilocks zone of rain, too little rain and too much rain – bad for trees, bad for fall foliage colors,” says Stephanie Spera, an environmental scientist at the University of Richmond
Spera and her team have been recording and studying the change in fall foliage in Acadia National Park; Spera predicts that the park’s peak now occurs two weeks later than it did in the 1950s. Spera projects that by 2060, peak foliage could happen as late as October 30- November 2, in contrast to this year’s peak of October 7-17.
While the climate crisis may evoke helplessness and sorrow, it is important to see how nature evolves and adapts. As temperatures change, species such as sugar maples will begin to move northward, and some scientists predict that the New England palette will shift more golden.
It is not too late to preserve the picturesque autumns we love. Still, as residents of New England, it is more important than ever to stay updated on how our ecosystems are affected by the climate crisis. These statistics and signs should remind us of the fragile beauty of our planet. As this fall draws to a close, set aside some time to walk through the woods or just sit outside admiring the leaves, remind ourselves not to take our environment for granted, and to appreciate the spectacle while it’s here.
