Figure 15.8 Declining trees in North America. The introduction of a fungus that causes Dutch elm disease killed many American elms, which used to be common along north American streets. (a) A street in Detroit, Michigan in 1974 before Dutch elm disease. (b) The same street in 1981 after Dutch Elm disease killed all of the elm trees.
Photos by Jack H. Barger, U.S. Forest Service.