It's a fabulous fall - and our expert can explain why all those colors come out this time of year

Oct 24, 2023

4 min

Robert T. Fahey, Ph.D.

Autumn has arrived.  And as we all take time to welcome this wonderous palette that nature delivers year after year, those who are curious about all those colors are looking for answers.


Why there are so many different shades, tints, and tones?


What causes the colors to change?


And where's the best place to find one of nature's finest displays of leaves?


It's a topic that comes up every year, and recently Connecticut Public Radio connected with UConn's Bob Fahey to get some of the answers about autumn in New England.


I ventured into a forest in northeastern Connecticut with two UConn tree experts. We met up at Horsebarn Hill, one of the best viewpoints in the state, surveying a rolling river valley showing off with fall colors.

We see oaks just starting to turn red. Nearby hickories provide a dash of yellow – and, of course, the maples are already stealing the show, even on a cloudy day.

Here’s what I found out:

Our trees are diverse

One reason the foliage is so good is simply due to the number of species we have.

“We have a very diverse hardwood forest in this part of New England,” said Bob Fahey, an associate professor and forest ecologist at UConn. “We have both species that are more southern species and also some of the more northern species.”

“In comparison to say, the Mid-Atlantic or other places that have lots of deciduous species, we have maples, which are just the best,” he said.

“We also have a number of species that have nice yellow foliage,” he said. “Birches and beech. If you go a little bit farther south from here, mostly what you have is oaks. And oaks can have good fall foliage colors, but there are a lot of times they don't and they don't last for as long.”



We have lots and lots of trees

The diversity of species provides a diversity of color, said Tom Worthley, an associate extension professor and a forester at UConn.

He asked me to remember the last time I flew over Connecticut. What did you see, he asked. Lots of trees, right?

“Most of the ground is covered by a tree canopy,” Worthley said, noting that some estimates put that tree canopy cover at around 75% of the land area of the whole state.

“Back where we were standing a few minutes ago, we had some cherry trees,” Worthley said, his eyes scanning the trees enveloping us. “There's a few remnant ash, there's some walnut around the edges here. And let's see, some hickory.”

A walnut tree towers over us – and there are even some white pines.

It’s that varied bioscape that sets New England forests apart.

“Even in my two-acre forest behind my house, I have 22 different species of tree, which is more than some regions of the northern part of the U.S.,” Fahey said.

Travel to the west, and what you’re likely to see are lots of evergreens and aspen trees.

“Not that there aren't others, there are plenty of others, but not in the same abundance and not in the same kind of mix that we have around here,” Worthley said.


Climate plays a role

Across New England are rolling hills with microclimates that can contribute to vibrant fall colors.

“You’ll see ... highly different color in different parts of the landscape, which has to do with temperature differences,” Fahey said.

Combine that with Connecticut’s mix of southern and northern species and the colors here might not be as exciting and bright as what you would see in Vermont and New Hampshire, Fahey said. But our foliage season can sometimes last a little bit longer.

One reason? Oaks.

“We have so much more of that oak component,” Fahey said. “The oaks will hold their leaves until the end of October.”

Moisture, temperature and the amount of daylight all contribute to how long it takes for a tree to shed its leaves. And, for each species, the calculation is different.

“A tree makes an economic decision,” Worthley said. “It decides, ‘Well, it's costing more in energy to keep these leaves going than what they're producing for me and so it's time to shut them off.’”


Why do leaves fall anyway?

It’s when leaves are green that the most important work is happening, pulling carbon out of the atmosphere and giving us oxygen.

And for that green color, we can thank the pigment chlorophyll.

“The color that's in the leaves – is always there from the time the leaf is grown,” Worthley said.

“As the growing season fades, the chlorophyll disappears,” he said.

Then the other colors in the leaf can begin to show off.

Pigments like anthocyanins (reds and purples) and carotenoids (yellows and oranges) peek out, tiny threads in an autumnal blanket transforming New England’s green forests into a richly colored landscape.



The colors are out - but only for a limited time.  If you're a journalist looking to know more about this topic before all the leaves fall, then let us help.


Dr. Fahey is an Associate Professor in the Department of Natural Resources and the Environment and Center for Environmental Sciences and Engineering at the University of Connecticut.


He is also the George F. Cloutier Professor in Forestry, director of the UConn Forest, and associate director of the UConn Eversource Energy Center. Simply click on his icon now to arrange a time to talk today.


Connect with:
Robert T. Fahey, Ph.D.

Robert T. Fahey, Ph.D.

George F. Cloutier Professor in Forestry

Robert Fahey is interested in understanding linkages between the composition, structure, and functioning of forest ecosystems.

ForestryNatural Resources Forest EcologyForest Ecosystems

You might also like...

Check out some other posts from University of Connecticut

2 min

Watching the solar eclipse Monday? Our expert has advice on how to do it safely

It's being called a "once in a lifetime" opportunity - and Monday's solar eclipse has almost everybody on the continent talking as well as planning and preparing to get a glimpse of this rare astronomical moment. Amid the excitement is a need for people to view the event safely, which is why NBC Connecticut recently caught up with UConn Associate Professor of Physics Jonathan Trump to explain what's happening and, if you're going to be gazing upwards, what you need to know and how to do it without getting hurt. An astronomical celebration is just around the corner. But if you want to see the solar eclipse for yourself, there are steps you need to take to do so safely. First and foremost: to watch this out-of-this-world display April 8, don’t even think about looking right at the sun. “Most important thing, do not look directly at the solar eclipse with your eyes,” said UConn associate professor of physics Jonathan Trump. “Here in Connecticut the eclipse will be about 90% which is pretty spectacular, but even 10% of the sun’s light is a lot of the sun’s light.” UConn is one of many organizations around the state holding a celebration and viewing event. “The next one is not going to be for another 20 years, so yeah this is a special event,” said Trump. Sunglasses aren’t strong enough to protect your retinas from these UV rays. “The ultraviolet light is what give us sunburns and it can severely damage the retina in the back of your eye and permanently scar your vision. So do not look directly at the sun,” said Trump. You can view the solar eclipse safely with certified solar eclipse glasses. If you wear eyeglasses, put the solar eclipse glasses on top of your glasses. And if you have solar eclipse glasses from the last phenomena visible stateside, which was seven years ago, you should get a new pair. Experts we spoke to say they have no more than a three-year shelf life.  Looking to know more?  Jonathan Trump is an observational astronomer and is available to speak with reporters about Monday's eclipse. Simply click on his icon now to arrange a time to talk today.

2 min

What Families Need to Know about How to Safely Store Firearms at Home

Guns have been identified as the leading cause of death for children in the United States, making ongoing discussions about firearm safety especially important. Kerri Raissian, an associate professor of public policy at the University of Connecticut, and Jennifer Necci Dineen, associate director of the ARMS Center for Gun Injury Prevention, recently co-authored an very important piece for The Conversation titled detailing what families need to know about safely storing firearms at home.  There were 2,571 children age 1 to 17 who died in shootings in the U.S. in 2021, 68% more than the 1,531 that occurred in 2000. To help reduce the number of firearm-related deaths and injuries among children, Secretary of Education Miguel Cardona in January 2024 called upon school and district administrators to talk with parents and guardians about safe firearm storage practices. As experts on the safe storage of firearms – and as leaders of the University of Connecticut’s ARMS Center for Gun Injury Prevention – we often get questions about the best ways to keep guns out of the hands of children. We offer the following tips: 1: Safely store all of your firearms 2. Don’t assume you can hide your guns 3. Store ammunition separately 4. Learn to talk about firearm safety 5. Know the law 6. Invest in a quality safe and/or locking device The full piece is available here from The Conversation. Kerri Raissian is an associate professor in the School of Public Policy at the University of Connecticut, director of the University of Connecticut's UConn’s Center for Advancing Research, Methods, and Scholarship (ARMS) in Gun Violence Prevention, and co-director of the Institute for Collaboration on Health, Intervention, and Policy (InCHIP) Gun Violence Prevention Research Interest Group. Her research focuses on child and family policy, with an emphasis on understanding how policies affect fertility, family formation, and family violence. She is available to speak to media about this important topic - simply click on her icon now to arrange an interview today.

5 min

Tianeptine - A so-called supplement with dangerous consequences. Our #expert weighs in on 'gas station heroin' warnings

Since 2022, the U.S. Food and Drug Administration has been actively urging consumers to avoid purchasing or consuming tianeptine -- a synthetic drug commonly called "gas station heroin" that can mimic the actions of opioids like fentanyl. Now, the FDA is upping the urgency of it's warnings as vendors continue to market the drug as a so-called "dietary supplement." UConn's C. Michael White, a Distinguished Professor of Pharmacy Practice, spoke with The Conversation about the problem with tianeptine in a must-read Q-and-A: What is tianeptine and why is it risky? Tianeptine stimulates the same receptors as well-known opioids such as fentanyl, heroin and morphine. When these drugs make their way from the blood to the brain, they bind to the “mu” type opioid receptor that triggers the sought-after pain relief and euphoria of those drugs as well as the dangerous effects like slowed or stopped breathing. High doses of tianeptine can bring euphoric effects similar to heroin and can also bring about the dissociative effect – the perception of your mind being disconnected from your surroundings and body – that is reminiscent of ketamine, an anesthetic that has a role in treating post-traumatic stress disorder and depression but has also commonly been abused as a street drug. Products containing tianeptine are often called “legal high drugs” – sometimes dubbed “gas station drugs” – a term used for all non-FDA-approved synthetic drugs that are sold casually in gas stations, online and elsewhere. What are the major adverse effects that people can experience? Data from clinical trials, case reports and poison control centers shows that tianeptine commonly induces agitation. This is typically accompanied by a fast heart rate and high blood pressure, confusion, nightmares, drowsiness, dry mouth and nausea, among other conditions. The most serious adverse events are slowed or stopped breathing, coma, heart arrhythmia and death. When long-term users try to stop tianeptine use, they often experience withdrawal symptoms reminiscent of opioid withdrawal. Consumers need to be aware that products containing tianeptine may not adhere to good manufacturing practices. This means they could contain lead or have other heavy metal contamination or be contaminated by microorganisms such as salmonella or mold. They could also contain other drug ingredients that are not disclosed. Knowingly or unknowingly combining active ingredients can increase the risk of adverse events. Additionally, the amount of the active ingredient contained in the product can vary widely, even with the same manufacturer. So past use does not guarantee that using the same amount will provide the same effect. How are these drugs sold in the US if they are not FDA-approved? If a drug product is not FDA-approved for prescription or over-the-counter-use, it is the Drug Enforcement Agency that is responsible for controlling market access. Before the DEA can ban an active ingredient in a drug product, it must be designated Schedule I, meaning the drug has no legitimate medical purpose and has high abuse potential. Manufacturers do not have to alert the DEA before selling their products to U.S. citizens. This means the DEA must detect an issue, identify the products causing the issue, identify the active ingredients in the product in question and do a full scientific review before designating it as Schedule I. Tianeptine came to market masquerading as a dietary supplement in gas stations and smoke shops, even though it is a synthetic compound. Tianeptine is also sold online allegedly for research purposes and not for human consumption. Tianeptine is undergoing clinical trials for the treatment of pain and depression, but sellers do nothing to make this type of labeling clear to consumers or to restrict purchases to researchers. What can people do to protect themselves and their families? Non-FDA-approved products containing synthetic drugs are very risky to use and should be avoided. FDA-approved drugs are available by a prescription from a health professional or over the counter with active ingredients on an approved list. If someone in a gas station, smoke shop or over the internet touts the benefits of a non-FDA-approved drug product – for pain or anxiety relief, to increase energy or for a buzz – be aware. It could be dangerous the first time you use it, but using it successfully once also doesn’t mean the experience will be the same the next time, and continued use can cause addiction. If a product is being sold “not for human consumption” or “for research purposes only,” you are at a high risk if you take it. Before you take any dietary supplement, make sure you check the active ingredient to be sure that it is, in fact, a natural product and not a synthetic chemical. If someone you know has bags with unmarked powder, a product labeled for research use or not for human consumption, or tablets or capsules not in standard drug bottles, that is a sign of a potentially dangerous situation. Standard drug tests sold over the counter are not designed to pick up tianeptine. One of the main reasons that people use these alternative substances of abuse over regular opioids, cannabis or amphetamines is that they are much harder to detect through work- or at-home drug screens by parents, schools, employers, probation officers and so on. If the DEA is not responding to emerging threats quickly enough, individual states can also act to ban sales of dangerous active ingredients in products. As of January 2024, at least 12 states have banned the sale of tianeptine, according to the FDA, although people in those states can still illegally procure it from the internet. So contacting your state legislators could be a place to start exercising your power to help prevent the harms from these products. This is an important piece, and if you are looking to know about tianeptine and the threat it poses to consumers in America, then let us help. Dr. C. Michael White is an expert in the areas of comparative effectiveness and preventing adverse events from drugs, devices, dietary supplements, and illicit substances. Dr. White is available to speak with media -- click on his icon now to arrange an interview today.

View all posts