American Chestnut

Posted on in Todd Talks by Todd Johnson

As I drive around the beautiful Pennsylvania countryside and see the trees, now fully in their summer skin, I cannot help but notice the standing skeletons of the once proud giants against the striking green hues of the forests. These grey ghosts are Ash trees – all victims of the Emerald Ash Borer Beetles. The wood from Ash trees is great for wood working. Specifically, baseball bats, bows, and even furniture. But in the late 1980s or early 90s, the Emerald Ash Borer was accidentally introduced in a shipment from Asia. The devastation this beetle brings has really only become evident in our area over the last 5-10 years. The insect made quick work of the millions of Ash trees in our woods. But I want to talk about another tree.

Decades before the Ash trees were chewed on by beetles, another tree that was once a common sight in the eastern American hardwood forests was being attacked. Arguably an even bigger ecological disaster than the Ash trees dying, the American Chestnut tree was a fixture of the American lumber industry for more than a century. With straight grain, rot-resistant lumber and delicious nuts that fed creatures of the forest as well as people, the American Chestnut tree was very important to the eastern US. The tree blossomed late in the spring, making the fruit almost immune to late frosts that can devastate other trees like apple. These trees grow fast as well. So, when they are cut and used as fence posts, telephone, and electric poles, and for houses because of how resistant they are to rotting, they can replenish much faster than other species. Unfortunately, in the late 19th century, some Japanese Chestnut trees were imported to New York, and it turned out that these trees were infected by the Asian Bark Fungus that would go on to devastate the trees. Once numbering more than 4 billion strong, American Chestnut trees now are so rare that finding one bigger than a few feet tall is a marvel. It is now estimated that around 430 million trees remain in their native habitat. That sounds like a strong number, until you hear that almost all of these are offshoots of long dead parent trees. The blight only kills the tree above ground. The root systems are still alive and well so you can still find small shoots coming up out of old stumps, but the blight will get them too. Usually within 5-10 years the fugus kills the tree before it can even flower or produce nuts. But there are some native trees that have some natural resistance to the blight that remain. It has been found that the fungus that causes the blight cannot survive the environment of the Pacific Northwest, so there have been trees planted there that are thriving.

There are other species of Chestnut that are blight resistant. The Japanese and Chinese Chestnut are both blight resistant examples. Efforts have been underway for more than 100 years to breed that resistance into their American cousins with varying degrees of success. Today there are even efforts to alter the genome of the tree to be resistant to the fugus. This method would be a much quicker fix than the breeding method. There has been considerable progress made towards restoring the American Chestnut to the forests of the eastern US, and this research has been critical to that objective.

Do you know of any Chestnut trees in your area? Do you need help identifying the different types of Chestnut? There are many great resources available online to help with identification. The American Chestnut Foundation is a great resource: This site also offers information on where you can send samples specific to your area. They also outline what items to collect and send.

With new blights and insects inevitably being introduced in the future, it’s imperative that we all take conservation of our natural resources seriously. The American Chestnut is a great place to start.