The process responsible for this is mass movement.
Answer:
The correct answer is fungi.
Explanation:
Fungi are the eukaryotic organism but they can be present in unicellular and multicellular form. They are different from plant, animals, and bacteria. They are heterotrophic organisms and do not conduct photosynthesis. Their cell wall is made up of chitin.
Most of the fungi are saprophytes which means they take their nutrition from the dead and decaying organism. So fungi play an important role in clearing the waste organic material from the environment so they help in bioremediation. All members of fungi comes under a separate kingdom fungi.
Secondary since plants/animals already lived there, but got killed/driven out of the area they lived/thrived in/on.