Why, how, and when leaves change color is a mystery scientists have been unraveling since the first sugar maple lit up an October afternoon. One of the most commonly asked questions regarding the color change is “Is this going to be a good year?”.  Many factors affect the brilliancy of the colors from year to year, with differing levels of predictability. Species composition of a forest is one major factor that will determine how colorful a vista is. If a forest is comprised mostly of hemlocks and pines, then you’ll see a green that changes little throughout the year. If you’re looking at a hillside full of maples and birch trees, with a few white pines mixed in, you’ll have a full palette of crimson, yellow, and nicely contrasting dark green.

Preceding and current weather also plays a role in determining what the leaves will do in a particular year. A very dry summer can stress trees, causing them to lose their leaves prematurely or change color ahead of the peak of the season, thus diminishing the effect.  Fall weather also affects color production. Cold, sunny days help in the production of anthocyanins, the chemical that produces the splendid red found in some leaves.Also, a stormy autumn can reduce fall foliage by knocking leaves off trees prior to peak of color display. Environmental factors can also influence when the peak of fall foliage will occur, though a good estimate is usually Columbus Day in October.

One reason why the roads of western Massachusetts fill up with slow moving cars in October? The beauty of the fall landscape that is due in large part to the fact that 79% of the region is wooded. Seventy nine percent. Now imagine how different autumn in Massachusetts would be without the region’s gorgeous scenery. Not only would we lose the aesthetic and environmental benefits of our woods, but we would lose significant tourist dollars as well as leaf peepers take their fall foliage tours elsewhere. While so much of the region is forested,the vast majority of it is not conservation land, but private lands that are subject to the needs, desires, and whims of private landowners.  It is up to these landowners to retain and manage their woods , and to realize their land is a small part of a greater landscape and ecosystem, in order to maintain the character and loveliness of western Massachusetts.

Just as conserving forest ecosystems keeps the habitat of Pseudacris crucifer healthy and intact, so too does it provide a good habitat in which autumn leaf peepers may flourish. MassACORN supports all woodland owners who are trying to enjoy and work their land sustainably, so that the autumn of the future remains as picturesque as it is today.

By Lisa Romano, Dept. of Natural Resources Conservation, University of Massachusetts