Differentiate between primary and secondary succession. Explain the various steps involved in primary community succession. (IFS 2019/10 Marks)
Differentiate between primary and secondary succession. Explain the various steps involved in primary community succession. (IFS 2019/10 Marks)
Introduction
Primary and secondary succession are two important ecological processes that occur in response to disturbances in an ecosystem.
Primary and Secondary Succession
| Aspect | Primary Succession | Secondary Succession |
|---|---|---|
| Definition | Succession occurring on newly formed or barren land | Succession occurring on previously colonized land |
| Starting Condition | Begins on lifeless areas without soil (e.g., lava flow) | Begins in areas with soil and some life remains |
| Initial Species | Pioneer species like lichens and algae | Early colonizers like grasses and herbs |
| Soil Formation | Soil is gradually formed over a long period | Soil already present, enhancing faster colonization |
| Time Required | Takes thousands of years to establish a stable community | Shorter time, as soil and nutrients are already present |
| Biodiversity Progression | Starts with low biodiversity, gradually increasing | Higher initial biodiversity, with gradual progression |
Steps Involved in Primary Community Succession
- Nudation
- The initial stage where a barren or new area, like bare rock or sand dunes, is exposed due to natural events (e.g., volcanic eruption).
- This area lacks any vegetation, soil, or established community.
- Pioneer Species Colonization
- Pioneer species, such as lichens, mosses, and algae, start colonizing the bare land.
- These species can tolerate extreme conditions and aid in breaking down rock into smaller particles.
- Soil Formation
- Organic matter from decomposed pioneer species mixes with rock particles to form thin soil.
- Small plants like grasses and ferns begin to grow, enriching the soil further.
- Intermediate Community Development
- Larger plants like shrubs and small trees begin to grow as soil quality improves.
- This increases nutrient levels, moisture retention, and habitat diversity for other organisms.
- Climax Community Establishment
- A stable, mature community with a diverse range of species and complex interactions is established.
- This climax community is resilient, maintaining ecological balance until disrupted by external forces.
Conclusion
Primary community succession is a complex process that involves the gradual establishment of plant communities in an area with no existing soil. The steps involved in primary succession is essential for studying the interactions between plants and animals in an ecosystem.