Why did chestnut blight greatly reduce the importance of the American chestnut?

The American chestnut (Castanea dentata) lost its ecological and economic importance primarily because it lacked natural resistance to chestnut blight, a lethal fungus (Cryphonectria parasitica) accidentally introduced from Asia in the early 20th century.12

The blight decimated the population, killing an estimated four billion trees. This had several profound impacts:1

• Ecological Collapse: Once a dominant species in the Appalachian Mountains and other eastern North American forests, the tree was largely eliminated, significantly altering forest structures.12
• Loss of Resources: The tree was a vital source of mast (nuts) for wildlife, such as turkeys, and provided high-quality, easily worked wood for the lumber industry.12
• Stunted Growth: Today, the species survives primarily as short-lived sprouts from old root systems, rarely reaching the size of the original "giants" that once defined the landscape.13

Because the fungus persists in other hosts and spreads easily via wind, rain, and insects, the American chestnut has been unable to recover its former status in the wild.12