Biology

The event that would not cause secondary succession is D. Tornado.

Secondary succession refers to the process of ecological succession that occurs in an area that has been previously inhabited but experienced a disturbance that removed the existing vegetation while leaving the soil intact. In secondary succession, new plants and organisms recolonize the area.

Options A, B, and C (forest fire, flooding of a valley, and volcanic lava flow) are all examples of disturbances that can lead to secondary succession. These events can clear the existing vegetation, creating space and opportunities for new plant species to colo...