By Allie Wisniewski, American Forests

Professor Lynda Mapes spent a year observing how a single tree reacted to seasonal changes. Credit: Joe Mabel

Everyone knows you can learn a lot about a person in a year. But what about a tree? That’s exactly what Professor Lynda V. Mapes set out to discover when she dedicated an entire year to studying a single 100-year-old red oak in the Harvard Forest. Unsurprisingly, Mapes grew awfully close to the ancient giant, both literally and figuratively.

With her two eyes and an additional two webcams ceaselessly tracking seasonal changes in its canopy, Mapes found the tree to be her ideal teacher, seeking a “fresh look at climate change beyond dueling politicians, press releases, or marches for the environment.”

Phenology is the observance of seasonal changes in nature, originating as early as the ninth century when Japanese monks took note of the first spring cherry blossoms. While mainstream science has traditionally characterized it as a mere hobby, phenology is now making a major comeback as researchers realize its potential ability to help identify and record changes in climate.

Biologist John O’Keefe, who has studied the same 50 trees in Harvard Forest for the past 25 years, deems nature an “articulate witness.” In fact, it was O’Keefe’s work that inspired Mapes to embark on her own long-term tree study with a hyperlocal focus. Only through this concentration was she able to observe in intimate detail the evolution of the New England landscape, shifts in seasonal timing and, of course, climate change. Even more, she noticed natural phenomena she would usually have been blind to, such as canopy shyness, vast communities of mosses, insects, and birds, and the unique song-like sounds produced when wind blows through tree branches.

What evidence of climate change was the red oak able to provide? Mapes observed that its growing season, like that of others in Harvard Forest, lasted longer than its own leaves. Even when weather remained warm and ideal for further development, the trees’ inner biological calendars urged them still to shut down for the year. The advent of longer growing seasons is disturbingly unnatural and slightly unnerving for Mapes. She says, “There are two calendars now: the seasonal timing evolved within living things and the seasons cooked up by us.” Not to mention, while warmer winters may seem desirable for red oaks and their forest neighbors, they provide the perfect opportunity for woolly adelgids to ravage Harvard Forest inhabitants such as the eastern hemlock.

After spending four whole seasons with the same red oak, Mapes emerged from the immersive experience confident that forests may help provide the solutions to their own problems. She emphasizes that even more than building material, fuel, and carbon-storage utilities, trees are sources of renewal and refuge for organisms from birds to rodents to humans. She urges us to understand that oaks (and forests in general) are more resilient than we may expect.

So, while climate change stories may seem, as Mapes puts it, “doom and gloom,” there is hope. She summarizes, “people and trees are meant to be together, and if we work at it, that’s how we will stay. Right here, dwelling in our common home on this beautiful earth, far into the future, amid the wonder of trees.”