Syllabus Edition

First teaching 2024

First exams 2026

Zonation, Succession & Change in Ecosystems (DP IB Environmental Systems & Societies (ESS): HL): Exam Questions

54 mins15 questions
13 marks

Define zonation in the context of ecological systems.

21 mark

State one abiotic factor that can cause zonation.

31 mark

Define the term succession.

41 mark

Outline one difference between primary and secondary succession.

51 mark

State one factor that increases as an ecosystem undergoes succession.

15 marks

Complete the table below by writing either 'low' or 'high' in each of the empty boxes.

Feature

r-strategist species

K-strategist species

Reproductive rate

 

 

Growth rate

 

 

Investment in offspring (parental care)

 

 

Survival rate

 

 

Level of specialisation

 

 

24 marks

Outline how various factors influence the resilience of an ecosystem.

32 marks

Explain how larger populations can affect ecosystem resilience.

41 mark

The figure below shows how the dominant vegetation and crop production changes with altitude in the Andes mountain range in South America.

crops-in-andes

The changes in dominant vegetation shows a distinct pattern.

State the ecological term used to describe this pattern.

53 marks

Outline how species diversity increases towards the later stages of succession.

64 marks

Describe the processes involved in the formation of fertile soils from bare rock.

73 marks

Discuss the factors contributing to the low resilience of coniferous forest monocultures.

17 marks

The biomass, biodiversity and productivity of an ecosystem change as the ecosystem undergoes succession.

Explain how.

29 marks

Discuss the extent to which the resilience of different biomes is influenced by their levels of primary productivity.

39 marks

Discuss the extent to which succession increases the stability and resilience of ecosystems.