Which statement correctly describes primary succession?

Primary succession refers to the process of ecological succession that occurs in an area where no soil exists and is often initiated on surfaces like bare rock following events such as volcanic eruptions or glacial retreats. This type of succession begins with the colonization of pioneer species, such as lichens and certain algae, which are capable of inhabiting such harsh environments. Over time, these organisms contribute to soil formation as they die and decompose, allowing for more complex plant communities to establish, leading to a more diverse ecosystem.

In contrast, the other statements do not accurately describe primary succession. For instance, describing primary succession as occurring in areas where soil is already present, or as a response to minor disturbances, illustrates a misunderstanding of its unique context; both reflect conditions that would be more aligned with secondary succession, where soil remains intact post-disturbance. Lastly, the idea that primary succession results from human impact mischaracterizes the natural processes involved, as primary succession is primarily driven by natural events that create new land without pre-existing soil.