1. How ecosystems recover from disturbances
4.3 Succession
How ecosystems recover from disturbances

2. Primary & Secondary Succession
What is ecological succession?
It is a series of predictable changes that occur in a community over time
2. What is primary succession?
Succession that occurs on surfaces where no soil exists (no life)
3. When a disturbance changes a community without removing the soil, what type of succession follows?
Secondary succession

3. 4. Describe the process of ecological succession Disturbance occurs - > plants begin regrowth, more animals reenter community 5. Why does secondary succession typically proceed faster than primary succesion? Primary takes out the soil whereas secondary still has soil

4. Venn Diagram- Compare two types of ecological succession
Primary Both Secondary
- Occurs on newly exposed surfaces (Bare rock, no soil)
- Takes a longer amount of time
Occurs when a disturbance does not destroy the soil
Takes less time than primary
Ecosystems grow and become more mature and complex

5. Picture Panels – Following volcanic eruption
- Correct order of panels: (from left-right) 1, 3, 4, 2 1: Volcano has erupted and covered area with rocks and ash. No organisms living here 2: pioneer species arrive (lichen) and as they die and decay they weather rock to form soil 3: soil accumulates, allowing grasses to grow 4: more plant species, trees able to grow

6. Climax Communities *Check for KEY concepts (Bolded sentences)
8. After a natural disaster occurs in a healthy ecosystem, secondary succession will cause the ecosystem to return to its original ________. Climax community 9. The clearing of a rain forest is the example of a ______________ drastic enough to prevent the original climax community from reforming. Human-caused disturbance

7. 10. During _________ succession, chance plays a large role in determining which pioneer species arrives in an area first. Primary 11. What are the two kinds of disturbances that change ecosystems? Give an example of each Natural – volcano, flood, hurricane, tornado Human-caused – clearing rain forest, farmer clearing field, controlled burning

8. Development of a climax community
Many abiotic and biotic factors determine how quickly ecological succession can cause a climax community to develop in an area. Give two factors that contribute to developing a climax community.
No major disturbances occurring
Basic necessities: Sun, water, etc.
More soil forming
Pioneer species
Increasing plant species
More niches available
Development of a climax community