Outline the procedures in a laboratory-based method to find the gross productivity for a population of named aquatic animals in terms of biomass per day.
Explain how acid deposition falling on a forest may impact a nearby aquatic ecosystem.
When harvesting is limited to the sustainable yield, associated processes involved in a food production system may still make the production unsustainable.
In this context, to what extent can aquatic food production systems be truly sustainable?
With reference to four different properties of a soil, outline how each can contribute to high primary productivity.
Explain how the level of primary productivity of different biomes influences their resilience.
Discuss the role of feedback mechanisms in maintaining the stability and promoting the restoration of plant communities threatened by human impacts.
Figure 2: Representation of the water cycle
Identify one transfer and one transformation process shown in Figure 2.
Transfer:
Transformation:
Outline how urbanization might impact two of the storages in Figure 2.
Runoff from agricultural land can result in excess nutrients entering water bodies. Outline one indirect measure of organic pollution.
Runoff from agricultural land can result in excess nutrients entering water bodies. State one management strategy that could control the release of agricultural runoff.
Distinguish between two named biomes and the factors that cause their distribution.
Evaluate one method for measuring primary productivity in a named ecosystem.
Discuss how human activities impact the flows and stores in the nitrogen cycle.
Figures 1(a) and 1(b) show the availability of renewable freshwater per capita in 2013 and its predicted availability in 2040.
Figure 1(a): Water stress by country in 2013
Figure 1(b): Predicted water stress by country in 2040
[Source: Maps adapted from www.wri.org. File licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)\]
Figure 2: Relationship between vegetation cover and evaporation
from different soil types
© International Baccalaureate Organization 2018
Using Figures 1(a) and 1(b):
State one country with no expected change in water stress between 2013 and the 2040 prediction.
State one difference in water scarcity between 2013 and the 2040 prediction.
Outline how climate change may affect the availability of freshwater resources.
Describe two water management strategies that can reduce water scarcity.
Describe the overall trend for sandy soil shown in Figure 2.
Calculate the change in evaporation from clay soil when the vegetation cover changes from 50% to 100%.
Outline two reasons why loam soils are the most productive for plant growth.
Identify four strategies that can be used in the sustainable management of wild fisheries.
Evaluate the sustainability of two water management strategies to improve access to freshwater resources in a society.
To what extent can the different environmental value systems improve the sustainability of food production?
Outline the reasons why natural capital has a dynamic nature.
Explain how the inequitable distribution of natural resources can lead to conflict.
The management of a resource can impact the production of solid domestic waste.
To what extent have the three levels of the pollution management model been successfully applied to the management of solid domestic waste?
Water stress is the total annual extraction of water as a proportion of the renewable supply in a given area. If the extraction represents 40 % or more of the available supply it is described as a high risk area.
Figure 2: Water stress for selected crops
[Source: World Resources Institute,
http://www.wri.org/resources/charts-graphs/portion-agricultural-production-under-high-or-extremely-high-stress.
Used with permission.]
State the crop that is under the greatest water stress.
Identify two strategies that could be used to grow crops in areas of high water stress.
Identify three factors that may lead to an increase in water stress.
Figure 3(a): Hurricane history of Dominica since 1900
[Source: Adapted from Dominica’s history with tropical storms. Available at: http://www.hurricanecity.com/city/dominica.htm.\]
Figure 3(b): Average global sea surface temperature, 1900–2015
[Source: NOAA.]
Figure 3(c): Impacts of Hurricane Maria
[text] Adapted from ACAPS, 2018. Dominica: The impact of Hurricane Maria. Available at:
https://www.acaps.org/sites/acaps/files/products/files/20180131\_acaps\_disaster\_profile\_dominica\_v2.pdf.
[left image] Photo credit: Marica Honychurch.
[right image] Photo courtesy of CARICOM, September 21, 2017,
https://caricom.org/carpha-ready-to-assist-dominica/.
Figure 3(d): Landslide caused by heavy rains after a hurricane
[Source: Photo courtesy of Jodie Dangleben.]
Using Figure 3(a), identify why Hurricane Maria was so destructive.
Describe the relationship between sea surface temperature in Figure 3(b) and hurricane wind speed in Figure 3(a).
With reference to Figures 3(c) and 3(d), outline how Hurricane Maria has reduced Dominica’s food availability.
With reference to Figure 3(c), explain three ways in which Hurricane Maria has affected ecosystem services provided by Dominica’s forests.
Outline the processes involved in the formation of fertile soils from bare rock.
Explain how negative and positive feedback mechanisms may influence the growth of decomposer populations in the soil.
To what extent are natural limiting factors more likely than population policies to limit global human population growth in the future?