Succession

Definition

Succession is the process through which ecosystems change and develop over time, involving a series of gradual changes in species composition and community structure. This process can be categorized into primary succession, where life begins in a previously uninhabited environment, and secondary succession, which occurs in areas where a disturbance has cleared out existing vegetation but left the soil intact. Understanding succession is essential for grasping how terrestrial biomes evolve and adapt to environmental changes.

5 Must Know Facts For Your Next Test

1. Succession can take decades or even centuries to complete, depending on the environmental conditions and species involved.
2. During primary succession, pioneer species like lichens and mosses are often the first to colonize barren landscapes, creating conditions suitable for other plants.
3. Secondary succession typically occurs more rapidly than primary succession because it begins with existing soil and plant life that can regenerate.
4. Disturbances such as fires, storms, and human activities can trigger secondary succession, leading to changes in species diversity and ecosystem function.
5. The concept of succession highlights the dynamic nature of ecosystems, demonstrating how they respond to both natural events and anthropogenic influences.

Review Questions

• How do primary and secondary succession differ in terms of their processes and outcomes?
  • Primary succession occurs in lifeless areas where soil has yet to form, while secondary succession happens in previously inhabited areas where a disturbance has occurred but soil remains intact. The outcome of primary succession involves the gradual buildup of soil quality through weathering and organic matter accumulation, whereas secondary succession often leads to quicker recovery due to existing seed banks and soil nutrients. This distinction is crucial for understanding how ecosystems recover from different types of disturbances.
• Discuss the role of pioneer species in primary succession and their importance in ecosystem development.
  • Pioneer species play a vital role in primary succession by being the first organisms to colonize bare substrates. These species, such as lichens and mosses, help to break down rocks into soil through physical weathering and contribute organic material as they die and decompose. Their presence improves the habitat for subsequent species by increasing soil nutrients and moisture retention, facilitating a more diverse community to establish over time. This initial stage sets the foundation for the entire ecosystem's development.
• Evaluate the impact of human activities on natural succession processes within terrestrial biomes.
  • Human activities, such as deforestation, urbanization, and agriculture, can significantly disrupt natural succession processes. These actions may lead to altered habitats that hinder the normal progression of ecological communities, often resulting in simplified ecosystems with reduced biodiversity. Additionally, some disturbances might necessitate restoration efforts to promote natural succession pathways. The understanding of these impacts is essential for developing conservation strategies that support ecosystem resilience and recovery.

Related terms

Primary Succession: The establishment of biological communities in an area that was previously devoid of life, such as after a volcanic eruption or glacier retreat.

Secondary Succession: The recovery process of an ecosystem following a disturbance that does not completely destroy the existing soil and seed bank, like after a forest fire or flood.

Climax Community: A stable and mature ecological community that has reached the final stage of succession, characterized by a relatively constant species composition and diversity.