Succession

Question 1

What are the main principles of succession?

Answer 1

• The change in plants and animal communities that takes place over time in an area
• certain species change the environment so it becomes more suitable for other species with different adaptations and less suitable for the previous species
• at each stage of succession there is interspecific competition between species
• the best adapted species dominate

Question 2

Describe the process of primary succession.

Answer 2

1. The first plant species to colonise the rock are called pioneer species, abiotic conditions are hostile and only the pioneer species have the adaptations to allow them to grow.
2. The pioneer species change the environment when they die and decomposed to increase the humus layer making conditions less hostile.
3. New species with different adaptations can move in and grow (colonisation)
4. The ecosystem becomes more complex and biodiversity increases which results in a climax community.

Question 3

Describe secondary succession.

Answer 3

1. This happens on land that has been cleared of trees, but where soil remains.
2. Similar to primary succession but starts at a later stage because the soil layer already exists with humus.

Question 4

When may secondary succession occur?

Answer 4

• After a forest fire
• When a field is abandoned, where previously crops were grown and harvested
• after deforestation takes place

Question 5

What is conservation?

Answer 5

Conservation attempts to maintain biodiversity by protecting and managing species and habitats in a sustainable way

Question 6

How is conservation involved in managing succession?

Answer 6

1. Preventing succession to preserve an ecosystem in its current state for example mowing, allowing animals to graze and burning moorland
2. Keeping seeded banks to re-introduce extinct species or increase the numbers of endangered species
3. Captive breeding programs to increase the numbers of endangered animals.
4. Fishing quotas to limit the number of fish caught and killed by people working in the fishing industry.
5. Protecting areas where urban development is restricted.