Which of the following situations is the best example of secondary ecological succession?

Introduction / Context:
This ecology question tests your understanding of primary and secondary succession. Succession describes how ecosystems develop or recover over time following a disturbance. Secondary succession occurs where a community has been disturbed but soil and some living organisms remain. Recognising real life examples helps you apply the concept beyond simple definitions.

Given Data / Assumptions:

• The question asks for an example of secondary succession.
• Options describe different scenarios such as new sediment, landscaping, reforestation, and growth on a new dune.
• Standard definitions of primary and secondary succession are assumed.

Concept / Approach:
Primary succession begins on surfaces where no soil and almost no life exist, such as bare rock, new lava, or newly exposed sand. Pioneer species slowly build soil over time. Secondary succession starts after a disturbance (fire, logging, farming, storms) in an area where soil, seeds, roots, or spores still remain. Because the substrate and seed bank are already present, secondary succession proceeds faster than primary succession. The key is whether the disturbance removed only the vegetation or removed both vegetation and soil. In this question, you must choose the scenario that clearly involves existing soil and prior vegetation, followed by regrowth of a community.

Step-by-Step Solution:

Verification / Alternative check:
Ecology textbooks commonly use forest regrowth after forest fires, storms, or logging as the standard example of secondary succession. They explain that, although mature vegetation is destroyed, the soil remains full of organic matter, seeds, and nutrients, allowing shrubs and trees to return relatively quickly. In contrast, primary succession examples include lava flows, glacial retreats, or newly formed dunes where no soil existed before. Comparing these textbook examples with the options confirms that reforestation of cedar forests clearly represents secondary succession, while the drained lake bottom and new dune resemble primary succession, and the golf course is a managed landscape.

Why Other Options Are Wrong:

New soil forming from sediment on the bottom of a drained lake is more like primary succession because plants colonise a newly formed substrate lacking established soil horizons.

Landscaping and mowing grass on a golf course is wrong because it is a human controlled activity, not an example of natural successional processes.

Scrub grasses growing on a newly exposed dune is incorrect as a secondary succession example because dunes often represent primary succession on fresh, unstable sand with minimal soil.

Common Pitfalls:
Students sometimes assume that any gradual change in vegetation is secondary succession, ignoring whether soil was present before. Another pitfall is to treat all regrowth as secondary, even when it occurs on newly exposed substrates without developed soil. To avoid confusion, remember that secondary succession begins where an existing community has been disturbed but soil remains, which is exactly what happens during natural reforestation of previously forested areas like cedar forests after logging or fire.