Scientists have studied the return of plant life on Mount St. Helens ever since the volcano erupted in
1980. Wildflowers began colonizing the area, followed by shrubs and small trees. Scientists predict
that it will likely take hundreds of years before the area returns to a forest dominated by fir and
hemlock trees. These changes are an example of:
a. humans degrading an ecosystem by removing wildflowers
b. the loss of genetic variation in a plant species
C. the growth of a forest through ecological succession
d. the biological evolution of wildflowers, shrubs, and trees