What process refers to the colonization of vacant but fertile land?

The correct answer pertains to primary succession, which is the process of colonization that occurs on previously uninhabited or barren land that has not been influenced by a preceding biological community. This can involve the establishment of life on surfaces such as bare rock, sand dunes, or areas created by volcanic eruptions or glacial retreats. During primary succession, organisms such as lichens and mosses are often the first to colonize these areas, gradually leading to more complex plant communities over time.

Secondary succession, on the other hand, refers to the re-colonization of an area that has been disturbed but still retains soil and some organisms, such as after a fire or human activity. This process typically occurs more quickly than primary succession since the soil and some seeds might already be present. Vernalisation relates to the chilling requirement of some seeds to enable them to germinate, and auxin is a plant hormone that plays a key role in growth and response to light, not in succession.

Understanding the differences between these processes is crucial for grasping how ecosystems develop and recover over time.