Time to check out the leaves on our native trees — but time’s getting short

The changing season at Rockwell Park. | JoAnn Moran

By JoAnn Moran |

The once-vibrant green canopy of trees shifts to a breathtaking palette of reds, oranges, yellows and purples, as autumn descends upon the landscape and the magical transformation begins.

New Englanders and visitors, captivated by the spectacle, make the trek through small villages following suggested routes to experience the best of the fall foliage season. Here in Bristol all we need to do is look up and around us–to South Mountain, Park Park or Rockwell Park, and up and down the streets in our neighborhoods or in our backyards.

This spectacle is particularly pronounced in the maple trees, whose leaves turn fiery shades as chlorophyll fades away. As the days grow shorter and cooler, the hidden pigments—carotenoids and anthocyanins—emerge, creating a stunning display like nature’s last hoorah before hunkering down for winter in the northeast.

Rockwell Park with its walking paths and open areas offers prime foliage viewing. | JoAnn Moran

The U.S. Forest Service (USFS) website includes insights into the science of fall colors.

“For years, scientists have worked to understand the changes that occur in trees and shrubs during autumn. Although we don’t know all the details, we do know enough to explain the basics to help you enjoy nature’s multicolored display. Three factors influence autumn leaf color:”

  • leaf pigments
  • length of night
  • weather

The USFS provides a simple breakdown of trees and their color changes.

Along the banks of the Pequabuck River and generally through Rockwell Park the leaves lend themselves to viewing. | JoAnn Moran

“Certain colors are characteristic of particular species:”

  • Oaks: red, brown, or russet
  • Hickories: golden bronze
  • Aspen and yellow-poplar: golden yellow
  • Dogwood: purplish red
  • Beech: light tan
  • Sourwood and black tupelo: crimson

Connecticut’s iconic maple leaf colors differ from species to species:

  • Red maple: brilliant scarlet
  • Sugar maple: orange-red
  • Black maple: glowing yellow
  • Striped maple: almost colorless

In contrast, some leaves of species such as elms simply shrivel up and fall, exhibiting little color other than drab brown.

Leaves tumble all around from the tops of maples, hickories and oaks. JoAnn Moran

But what happens to all those fallen leaves? Needles and leaves that fall are not wasted. They decompose and restock the soil with nutrients, forming part of the spongy humus layer of the forest floor that absorbs and holds rainfall. Fallen leaves also become food for numerous soil organisms vital to the forest ecosystem, supporting a web of life that thrives beneath the surface.

Along the railroad tracks off Terryville Avenue and more from Rockwell Park. | JoAnn Moran

Meanwhile, the evergreens, such as spruces, stand resilient against the seasonal changes. Their needle-like leaves remain steadfastly green, thanks to their thick, waxy cuticles and the persistent presence of chlorophyll. While evergreens don’t showcase the vibrant fall colors of deciduous trees, they add a rich, consistent green backdrop to the landscape throughout the seasons, providing a lush contrast to the fiery hues of their leafy neighbors.

Recent research has unveiled intriguing insights into this seasonal transformation. Scientists are exploring how climate change alters the timing and intensity of fall colors, revealing that warmer temperatures can lead to earlier or less vivid displays. Genetic studies delve into the specific mechanisms that determine pigment production, helping to predict how various tree species will respond to shifting environmental conditions.

Moreover, as trees prepare for winter, they recycle nutrients from their leaves, influencing the pigments produced and ultimately affecting the colors that emerge. Environmental stressors, such as drought, also play a role, leading to changes in the production of anthocyanins and other pigments. Researchers are even investigating the ecological significance of these color changes, examining how they affect interactions between plants, herbivores, and pollinators.

While some trees have dropped their leavers, others hold on. | JoAnn Moran

As the leaves begin to fall, a rich tapestry of color blankets the ground, reminding us of the beauty and complexity of nature. Each vibrant leaf tells a story of adaptation and resilience, a vivid reminder that even as the seasons change, life continues to thrive in all its forms. In this stunning autumn display, the dance between deciduous and evergreen trees creates a symphony of color, a celebration of nature’s artistry as it prepares for the quiet of winter.

For information, follow this link to the USFS website: https://www.fs.usda.gov/visit/fall-colors/science-of-fall-colors#:~:text=Both%20chlorophyll%20and%20carotenoids%20are,unmasked%20and%20show%20their%20colors.


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