Which disturbance would result in primary succession?

• A. A forest fire clearing an existing forest
• B. A flood depositing sediment in a river valley
• C. A volcanic eruption creating new land
• D. A hurricane damaging a coastal ecosystem

Answer: (C)

Verified step by step guidance

1. Understand the concept of ecological succession: Ecological succession is the process by which the structure of a biological community evolves over time. There are two main types: primary and secondary succession.
2. Define primary succession: Primary succession occurs in an area where no previous ecosystem existed. It starts on bare rock or newly formed land, where soil has not yet developed.
3. Identify the characteristics of primary succession: It involves the colonization of new land by pioneer species, such as lichens and mosses, which can grow without soil and help in soil formation.
4. Analyze the disturbances listed: A forest fire, flood, and hurricane all affect existing ecosystems where soil is already present, leading to secondary succession. In contrast, a volcanic eruption creates new land, providing a fresh surface for primary succession.
5. Conclude why a volcanic eruption leads to primary succession: The eruption creates new land devoid of soil, making it suitable for primary succession as pioneer species begin the process of soil formation and ecosystem development.