American chestnut

The American chestnut is a large and fast-growing tree. It belongs to the beech family. This tree is a deciduous hardwood, which means it loses its leaves each year.

You can recognize its leaves by their long and broad shape. The edges of the leaves have large, widely spaced saw-teeth. This trait is why its scientific name is *Castanea dentata*. The word *dentata* is Latin for "toothed."

These trees are important because they produce many edible nuts. The nuts grow inside a spiny, green shell called a burr. Each burr usually holds three nuts lined with tan velvet.

This tree once ruled much of the eastern North American forests. It was a dominant species in the oak-chestnut forest regions. The trees grew well on steep slopes with acidic soil. They were very helpful to the environment and local animals. For example, black bears would eat the nuts to get fat for winter. White-tailed deer and wild turkeys also relied on them for food.

The trees also helped the soil stay healthy. Their leaves contain nitrogen, phosphorus, potassium, and magnesium. When the leaves fall, they return these nutrients to the ground. This helps other plants and tiny living things grow.

Everything changed in the early 20th century due to a sickness. This sickness is called chestnut blight. It is a fungal disease caused by an Asian bark fungus. The fungus arrived when infected Japanese chestnut trees were brought to North America.

The blight was first noticed in 1904 at the New York Zoological Park. A forester named Hermann Merkel saw the disease there. He estimated that 98 percent of the trees in that area were infected by 1906. The disease works by girdling the tree. This means it wraps around the trunk and stops the tree from living. It is estimated that the blight killed between three and four billion trees.

Today, the American chestnut is in a very hard spot. It is listed as endangered in Canada. Most of the original population was lost, leaving only one to ten percent of the original size. Some trees still grow, but they are often just saplings that die before they get old. There are about 600 to 800 large trees in Northern Michigan.

Scientists are working hard to find a way to save the species. One group uses cross-breeding to make trees that can fight the blight. They might cross the American chestnut with the Chinese chestnut. This helps them keep the genes of the American tree while adding resistance.

Other scientists are using a very modern way to help. Researchers at the SUNY College of Environmental Science and Forestry created something called the Darling 58 cultivar. They did this by putting a gene from wheat into the chestnut.

This gene helps the tree make an enzyme. This enzyme breaks down the acid made by the blight. This stops the fungus from hurting the tree's inner trunk. As of 2021, researchers are asking for permission to share these trees with the public. If they are allowed, these would be the first genetically modified forest trees released into the wild in the United States. This work could help the American chestnut return to its home in the forest.