Which of the following scenarios represents change to an ecosystem brought about by biotic factors?

a. a wildfire caused by lightning striking a tree

b. a flood caused by a severe storm

c. a landslide caused by cattle overgrazing

d. a volcano

The change to an ecosystem that is brought about by the biotic factors is the the landslide caused by the cattle overgrazing. The answer is letter C. The word biotic means the factor should be living thing (s). Among the choices, only the cattle is living organism.