Events that occur in four different ecosystems are shown in the chart.
ECOSYSTEMS
Ecosystem Events
A A severe ice storm occurs during the winter, damaging trees and shrubs. No ice storms occur for the next twenty years.
B A severe drought causes most of the leaves to fall from the trees during a single summer. There are no serious droughts for the next twenty years.
C An island with a dense shrub population becomes submerged for three years. When the river water lowers, the island does not become submerged again for the next twenty years.
D A fire burns through a large grassy area. Fires do not occur in the area for the next twenty years.
Which ecosystem would require the longest period of time to return to its original state?
a
Ecosystem C
b
Ecosystem D
c
Ecosystem B
d
Ecosystem A