Loading Events

Clear Day Thunder: Rescuing the American Chestnut

February 18 @ 2:00 pm - 4:00 pm

The American Chestnut Foundation’s (TACF) documentary, Clear Day Thunder:  Rescuing the American Chestnut, will be shown at The Connecticut Audubon Society (CAS) Center at Pomfret on Sunday, February 18, at 2:00 p.m. The screening will be followed by a question and answer session with Jack Swatt, president of the Connecticut chapter of TACF, and Ginny Patsun, manager of the TACF seed orchard in Stafford. The event is presented in collaboration with The Wyndham Land Trust. No registration is required and there is no admission charge.

Clear Day Thunder tells a story that will interest a number of audiences, including citizen scientists, history buffs, and forestland owners. When European colonists first came to Connecticut, the land was heavily forested with chestnut, oak, and pine trees. Estimates are that chestnuts comprised up to 25% of the forest in what was to become Connecticut. The trees grew quickly and many of them became massive, producing thousands of nuts. They were both economically and ecologically important. Chestnut lumber, straight-grained and rot-resistant, was used extensively in building and furniture making. Nuts were food for any number of insects, birds, and mammals. They were not only mast for wildlife but also feed for domestic animals. Farmers grazed cattle and pigs in the woods, fattening them for home use or the market. Chestnuts also were harvested and roasted or pounded into meal to be eaten by people.

In the late 1800’s/early 1900’s, a fungal canker disease was unintentionally introduced to North America on plants imported from Asia. Sweeping through the forest, the blight killed mature chestnut trees, which had no resistance to it. Underground and not exposed to the airborne fungus, their root systems often survived and sent up sprouts. These soon became diseased and survived only a few years. A few lived long enough to produce nuts. Even today, more than a century after the introduction of the blight, this remains the case. There are not, however, enough of these trees to maintain a viable, reproducing population. Thus, the American chestnut tree is functionally extinct.

Clear Day Thunder explains why there still is hope for the American chestnut. The Chinese chestnut evolved with the fungus and has resistance to it. Back crossing of American and Chinese chestnuts for many generations has resulted in trees with some blight resistance. Scientists also have developed a genetically modified American chestnut. Researchers inserted a single gene from wheat that encodes for oxalate oxidase, an enzyme that breaks down the toxic oxalic acid that the blight fungus uses to damage the chestnut’s bark. The genetically engineered chestnut tree, like all transgenic plants, must be approved by the federal government before it can be made available to the public.

The phrase “clear day thunder” has a sad derivation. It is a description of the sound of gigantic, dead chestnut trees crashing to the forest floor. Clear Day Thunder shows how passionate people involved in the restoration effort are motivated to bring this iconic tree back to the forests of the east.


Connecticut Audubon Center at Pomfret
218 Day Rd.
Pomfret Center, CT United States
+ Google Map