Seasonal Cycles: Autumnal Tints

“Nature herself holds her annual fair in October, not only in the streets, but in every hollow and on every hill-side.” As Thoreau eloquently describes, fall in New England is marked by the transformation of green leaves to vibrant displays of reds, oranges, and yellows. This color change marks the preparation of trees for the winter ahead and occurs in response to a mixture of factors including cooling temperature, shortening days, and declining water availability. Chlorophyll, the pigment responsible for photosynthesis and the green color of leaves, begins to break down, and trees reabsorb valuable nutrients from the leaves before the leaves eventually fall from the branches.

Although fall phenology has not been documented or studied nearly as well as seasonal events in spring, there is evidence that this shift into winter is occurring later now than in the past as a response to climate warming. Because leaf color and drop are less sensitive to temperature than budburst and flowering, the delay of autumn seems to be less pronounced than the early arrival of spring.

inscribed leaf

Sophia Thoreau, Henry’s sister, was particularly skilled at botanizing and creating pressed herbarium specimens.

North Bridge, Concord, Mass. Postcard

The tints of autumn made New England a tourist destination and postcards such as this one of the North Bridge in Concord found favor as souvenirs.

Oak tree leaf

Oak trees constitute the genus Quercus. There are over a dozen species of native oaks growing wild in eastern Massachusetts, and as many again cultivated here.

To Learn More

Listen to the sounds of autumn that one might hear at Walden Pond.

Read the text of “Autumnal Tints” by Henry Thoreau.

Learn why leaves change color.

Photo/soundscape credits: David Bohl; Cherrie Corey; Kezia Simister