Secondary succession

Definition

Secondary succession is the ecological process of recovery and development that occurs in a previously disturbed area where soil and some organisms still remain. This process follows events such as fires, floods, or human activities that disrupt an ecosystem but leave the underlying soil intact. It is characterized by a faster recovery time compared to primary succession because the soil already contains nutrients and seed banks, allowing for quicker establishment of plant communities.

5 Must Know Facts For Your Next Test

1. Secondary succession can happen more quickly than primary succession, typically taking place over a few years to several decades depending on the severity of the disturbance.
2. The presence of soil in areas affected by secondary succession allows for quicker germination of seeds and regrowth of plant life compared to areas undergoing primary succession.
3. After disturbances like forest fires, certain species adapted to thrive in post-fire conditions can emerge quickly, contributing to the resilience of the ecosystem.
4. In many ecosystems, secondary succession leads to the re-establishment of complex food webs and biodiversity that had been lost during the disturbance.
5. Human activities, such as agriculture or logging, often trigger secondary succession as these practices leave behind soil and seeds that can promote regrowth.

Review Questions

• How does secondary succession differ from primary succession in terms of time and processes involved?
  • Secondary succession differs from primary succession primarily in that it occurs in areas where soil and some organisms remain after a disturbance. This allows for a faster recovery process, as nutrients are already available and seed banks are present. In contrast, primary succession starts from bare rock or substrate with no soil, which requires a longer period for soil formation and establishment of plant life.
• Discuss the role of pioneer species in secondary succession and their impact on ecosystem recovery.
  • Pioneer species play a critical role in secondary succession by being the first organisms to colonize a disturbed area. These species help stabilize the soil, add organic matter as they grow and die, and create conditions favorable for other plants to establish. Their presence often leads to increased biodiversity as they facilitate the growth of more complex plant communities, ultimately helping restore the ecosystem.
• Evaluate the implications of human-induced disturbances on secondary succession processes and long-term ecosystem health.
  • Human-induced disturbances can significantly impact secondary succession processes by altering species composition and affecting ecosystem resilience. For example, practices like logging or urban development can disrupt natural habitats and introduce non-native species that compete with local flora. While secondary succession may still occur, its trajectory may be altered, potentially leading to less diverse or less stable ecosystems over time. The long-term health of these ecosystems can be compromised if recovery processes are hindered or if invasive species dominate.

Related terms

primary succession:

Primary succession refers to the colonization and development of an ecosystem in an area that was previously uninhabited and devoid of soil, such as after a volcanic eruption.

pioneer species:

Pioneer species are the first organisms to colonize a disturbed area during succession, often including lichens, mosses, and certain types of grasses.

climax community:

A climax community is a stable and mature ecological community that has reached the final stage of succession, exhibiting little change in species composition over time.