Question

What has caused the widespread decline of the American chestnut tree?

global warming

changes in farming habits

a fungus

scientists

Answer 1

The widespread decline of the American chestnut tree was primarily caused by a fungus known as *Cryphonectaria parasitica*, which causes a disease called chestnut blight. This invasive pathogen was introduced to North America in the early 1900s, and it decimated the American chestnut population, which was once one of the dominant tree species in eastern forests. While factors like global warming and changes in farming habits could have indirect effects on forest ecosystems, the direct cause of the decline is the chestnut blight fungus. Scientists have been working on various methods to restore the American chestnut tree, including breeding for blight resistance.