Which type of succession would occur after the melting of a glacier or a volcanic eruption?

• A. Secondary succession
• B. Primary succession
• C. Climax community
• D. Pioneer species

Answer: (B)

Primary succession is the process that starts on surfaces with little or no soil, like bare rock exposed by a melting glacier or fresh lava from a volcanic eruption. In these environments there are no remnants of a previous community to re-colonize the area, so the first inhabitants are hardy pioneers such as lichens and mosses. These organisms can tolerate extreme conditions, begin to break down rock, and add organic material that slowly forms soil. As soil develops, grasses and herbs establish, followed by shrubs and eventually trees, leading to a more complex, stable community over time.

Secondary succession would occur in a setting where soil and some life remain after a disturbance, such as after a wildfire or farming abandonment, so the starting point is different. A climax community refers to the endpoint of succession, not the initiating process, and pioneer species are the early colonizers, not the type of succession itself.