Topic 1: Foundation

1.1 Perspectives

1.2 Systems

1.3 Sustainability

Topic 2: Ecology

2.1 Individuals, populations, communities, and ecosystems

2.2 Energy and biomass in ecosystems

2.3 Biogeochemical cycles

2.4 Climate and biomes

2.5 Zonation, succession and change

Topic 3: Biodiversity and conservation

3.1 Biodiversity and evolution

3.2 Human impact on biodiversity

3.3 Conservation and regeneration

Topic 4: Water

4.1 Water systems

4.2 Water access, use and security

4.3 Aquatic food production systems

4.4 Water pollution

Topic 5: Land

5.1 Soil

5.2 Agriculture and food

Topic 6: Atmosphere and climate change

6.1 Introduction to the atmosphere

6.2 Climate change—causes and impacts

6.3 Climate change—mitigation and adaptation

6.4 Stratospheric ozone

Topic 7: Natural resources

7.1 Natural resources—uses and management

7.2 Energy sources—uses and management

7.3 Solid waste

Topic 8: Human populations and urban systems

8.1 Human populations

8.2 Urban systems and urban planning

8.3 Urban air pollution

HL.a Environmental law

HL.b Environmental economics

HL.c Environmental ethics

IB ESS SL 2.3 Biogeochemical cycles Question Bank

[Maximum number: 2]

Figure 1 shows the process of carbon capture and storage (CCS) that can be used to manage climate change. Carbon dioxide ( $\mathrm{CO}_{2}$ ) is pumped into three different underground locations, where it is stored.

Flow 1 pumps $\mathrm{CO}_{2}$ into an underground saline reservoir.
Flow 2 pumps $\mathrm{CO}_{2}$ into an oil reservoir; $\mathrm{CO}_{2}$ replaces oil; oil is produced.
Flow 3 pumps $\mathrm{CO}_{2}$ into a coal seam; $\mathrm{CO}_{2}$ replaces methane $\left(\mathrm{CH}_{4}\right)$ ; methane is produced.

Figure 1: Carbon capture and storage flow chart

(a)

Outline how Flows 1 and 2 shown in Figure 1 may contribute to the capture and storage of atmospheric carbon.

[ 2 ]

(a)

Bithynia feeds on plant material in the wetland ecosystem.

[ 2 ]

(i)

Describe its role in the carbon cycle of the system.

[ 2 ]

(a)

Figure 8(a): River before and after beaver dam construction

Figure 8(b): Graphs to show nutrient and oxygen content in beaver pond and stream

With reference to Figures 8(a) and 8(b), describe the changes in nutrient and oxygen content that occur after beaver dams are constructed. Include quantities in your response.

[ 2 ]

[Maximum number: 2]

Ecosystem	Soil carbon	Living biomass	Total carbon
Boreal forest	150	94	244
Tropical forest	83	167	250
Mangroves	1030	464	1494
Tidal marsh	920	31	951
Seagrass meadows	608	10	618

Figure 6: Carbon storage in different ecosystems

With reference to Figure 6, outline the effectiveness of mangroves and tropical rainforests in the mitigation of climate change.

(a)

Outline how the change in the area of forest cover since 1987 may contribute to the mitigation of climate change.

[ 1 ]

[Maximum number: 3]

Figure 3: Climate data for Norilsk and Novosibirsk within the tundra and taiga biome respectively

Siberian taiga
- Taiga forest provides habitat, stores carbon, helps regulate climate and supplies timber.
- Deforestation can affect biodiversity, carbon storage and downstream/global systems.

(a)

Explain how deforestation in the taiga may impact the world's oceans.

[ 3 ]

(a)

Describe how carbon dioxide is added to the atmosphere through natural and human processes.

[ 5 ]

[Maximum number: 3]

Figure 3 shows an incomplete model for the nitrogen cycle.
Figure 3

(a)

Label the diagram above to complete the processes and flows in the nitrogen cycle.

[ 3 ]

(a)

Compare and contrast the impact of humans on the carbon and nitrogen cycles.

[ 7 ]

0 selected

Question 1

Question 1(e)

Question 1

Question 1(e)

Question 1(e)(ii)

Question 4

Question 4(a)

Question 10

Question 5

Question 5(b)

Question 6

Question 6(c)

Question 4

Question 4(a)

Question 5

Question 5(a)

Question 7

Question 7(b)