Howard Neufeld is known as the Fall Color Guy. It’s his Facebook page – facebook.com/fallcolorguy – his twitter handle (@fallcolorguy) and it’s the role he’s adopted. This biology professor at Appalachian State is one of the few scientists worldwide to study the hows and why of fall color. His color forecasts are as accurate as they get, and he’s worked with everyone from the N.C. Division of Tourism to Explore Asheville to get the word out about Western North Carolina’s fall leaves. Why? Because he loves fall, has a passion for the science behind the beauty, and because he wants you to get out and enjoy nature in all its glory.
After I got a job with Appalachian State in 1987, I was introduced to this little plant that grows in the woods here called galax. It was obvious that this was an interesting plant because in the fall, the leaves would turn a bright red if they were in the sun. I realized no one had studied it much, so I kept an eye on it, looking for a research opportunity. A student was interested, so I asked her, “Why does galax turn red in the winter? And does it turn back green?”
She took it and ran with it, and we published a major article in the International Botanical Journal that showed that the red seemed to act as a light screen, protecting those leaves in the winter because they are susceptible to high light when they’re cold. Right about that time, two independent sets of researchers came out with the same hypothesis – that the red color may protect those leaves from getting too much light in the fall and help the plants retranslocate nutrients from the leaves back into the twigs so they can store them and use them for next year’s leaves. That made me start to look more closely at fall color.
Word of my research got out, and people started calling me saying, “What do you think the color’s going to do this fall?” And I started telling them what I thought. It wasn’t based on much beyond experience, but as it turns out, there wasn’t a lot of science out there on what makes for a good fall color season.
The other thing in North Carolina is the incredible elevation gradient. We’ve got the highest point in the Eastern U.S. at Mount Mitchell and the second tallest in Clingman’s Dome; then you go all the way down to Charlotte where you’re only 750 feet above sea level. The fall colors start earlier at the higher elevation – it gets colder sooner there – and you can watch this wave of color move down the mountains at about 1,000 feet every week to 10 days. That means our fall colors can be spread out over a month and a half whereas in New England it’s about a two-week period; then it’s gone.
For visitors, this means you could see fall color on five or six consecutive weekends.
When you have sunny days in the fall, the trees can do photosynthesis and make those sugars. The cool temperatures tend to slow down the movement of the sugars out of the leaf, so the sugars build up, which triggers a lot of anthocyanin production. That’s why if it’s rainy or cloudy or warm in the fall, the colors look a little duller.
That’s what makes August and September important for good fall color: That’s when the trees are determining how much anthocyanins they make. If it’s rainy in August and September, you get fewer anthocyanins and dull color. If it’s sunny and cool, as it was this year, that’s the perfect set of conditions to make this pigment. August and September were ideal this year.