Fungi from other parts of the world have caused ecological disasters in the U.S. during the last century. The American chestnut tree commonly grew in forests from Michigan to Louisiana and from Maine to Georgia. In the 1900s an invasive species, commonly known as , decimated the chestnut tree population leading to one of the worst ecological disasters in U.S. history. It is thought that the invasive fungus was imported from Japan and China. Other invasive fungi have destroyed large numbers of redbay, dogwood, and oak trees. Is human activity to blame for such disasters? What can be done to alleviate this problem?