Question

how does the timeline of primary succession compare to that of secondary succession?
both types of succession occur at the same rate.
secondary succession occurs faster because soil is already present.
primary succession occurs faster because it starts with bare rock.

Explanation:

Primary succession occurs in areas where there is no soil (e.g., bare rock), and the process of soil formation (through lichens, mosses, etc.) takes a long time. Secondary succession occurs in areas where soil is already present (e.g., after a forest fire in an area that previously had a forest). Since soil is already there in secondary succession, the establishment of plants (which need soil for anchorage, water, and nutrients) happens more quickly.

Answer:

Secondary succession occurs faster because soil is already present.