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How did chestnut blight affect chestnut forests in the United States?

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Two Amanita pantherina mushrooms with brown caps covered in white spots grow among moss and fallen leaves. — fungus A pair of panther cap mushrooms (*Amanita pantherina*). Closely related to the death cap mushroom (*Amanita phalloides*), the panther cap is highly poisonous.

Chestnut blight is a plant disease caused by the fungus Cryphonectria parasitica, which was accidentally introduced to the United States from Asia. First observed in 1904, the disease spread rapidly, killing an estimated four billion American chestnut trees.1

The impact on United States forests was profound:
* Ecological Alteration: The American chestnut was once a dominant species in the Appalachians and other regions. Its loss significantly altered forest structures.12
* Loss of Resources: The trees provided abundant mast, which served as a primary food source for wildlife such as turkeys, and were a major source of high-quality timber.12
* Economic Impact: The destruction of these trees caused severe economic damage to the nut and lumber industries.1

The fungus persists in sprouts from old roots and other host species, making it nearly impossible to eradicate. Current restoration efforts focus on using hypovirulent strains of the fungus and breeding hybrid chestnut varieties to introduce genetic resistance into the gene pool.1