Identify four ways to ensure reliability of the mark–release–recapture method in estimating population size.
Explain how the interactions between a species and its environment give rise to the S-shape of its population growth curve.
The future growth of human populations is unlikely to be limited by the availability of energy resources. However, they could easily be limited by the impacts of energy production.
Discuss the validity of this statement.
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.
Outline why top carnivores are vulnerable to non-biodegradable toxins.
Explain two factors which lead to a loss of marine (ocean) biodiversity.
Evaluate one possible pollution management strategy for solid domestic waste.
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.
Outline one method for measuring the impact of a build-up of dead organic matter in an aquatic ecosystem.
Explain how models of ecosystems might be used in species conservation.
Discuss how the introduction and re-introduction of a species can affect an ecosystem.
Figure 1(a): Savanna food chain
[Source:Djsudermann, 2019. [Elephants in the Savannah] [image online] Available at: https://pixabay.com/photos/
elephant-trees-savannah-sky-animal-4121954/ [Accessed 29 September 2020]. Source adapted.
designerpoint, 2012. Lion-wildcat-safari-africa-515030. [image online] Available at: https://pixabay.com/photos/
lion-wildcat-safari-africa-515030/ [Accessed 3 September 2020].]
Figure 1(b): Biting flies in the savanna
Biting flies bite and drink the blood of zebras. They commonly carry diseases that can be fatal to zebras.
[Source: [Tsetse fly] 2006. [image online] Available at: https://commons.wikimedia.org/wiki/File:Tsetse\_fly.png [Accessed 22
May 2020]. Source adapted.
Wellcome Material: Tropical Medicine, 2014. Illustration of ‘Tabinus socius’. [image online] Available at:
https://commons.wikimedia.org/wiki/File:Illustration_of_%27Tabinus_socius%27;_Tropical_Medicine_Wellcome_
L0025345.jpg. Second report of the Wellcome Research Laboratories at the Gordon Memorial College, Khartoum
/ Andrew Balfour. https://wellcomecollection.org/works/ez3txjfg. Attribution 4.0 International (CC BY 4.0)
https://creativecommons.org/licenses/by/4.0/deed.en[Accessed 22 May 2020]. Source adapted.]
State the trophic level of the zebra.
State how you could determine gross secondary productivity of the zebra.
Explain how the second law of thermodynamics applies to this food chain.
State the type of relationship that exists between biting flies and the zebra.
Zebra stripes may reduce the ability of the biting flies to land on the zebra. Describe how natural selection may have led to the evolution of zebra stripes in response to biting flies.
Figure 3: The number of plant species present on the slopes of two volcanoes, whicherupted in the 1880s. Measurements were taken in 1930, 1975 and 2015.
[Source: Data courtesy of Roger del Moral]
State the ecological processes illustrated by the data in Figure 3.
Describe a method for measuring the abundance of plant species in volcanic areas.
Suggest two reasons why there are differences in the number of plant species foundon Krakatau and Tarawera.
Figure 5: Fact file on deer species found in London
[Source:Nilfanion, 2010. Muntjac deer at Dumbleton Hall. [image online] Available at:
https://fr.wikipedia.org/wiki/Fichier:Muntjac_deer_at_Dumbleton_Hall.jpgAttribution-ShareAlike 3.0 Unported (CC
BY-SA 3.0) https://creativecommons.org/licenses/by-sa/3.0/deed.en[Accessed 22 May 2020]. Source adapted.
Lviatour, 2011. Cervus elaphus Luc Viatour 6. [image online] Available at:
https://commons.wikimedia.org/wiki/File:Cervus_elaphus_Luc_Viatour_6.jpgAttribution-ShareAlike 3.0 Unported
(CC BY-SA 3.0) https://creativecommons.org/licenses/by-sa/3.0/deed.en[Accessed 22 May 2020]. Source
adapted.
Manfred Antranias Zimmer /Pixabay.com, 2018. Striking Fallow Deer Buck, boasting an impressive rack. [online]
Available at: https://pixabay.com/photos/antler-fallow-deer-deer-dama-dama-899123/\[Accessed 13 September
2021].]
Figure 6(a): Population of deer in Richmond Park, 2013–2017
Figure 6(b): Number of deer removed from Richmond Park, 2013–2017
Figure 6(c): Fact file on Richmond Park
Richmond Park is a national nature reserve and Special Area of Conservation.
[Source:The Royal Parks, 2020. Deer in Richmond Park. [online] Available at: https://www.royalparks.org.uk/parks/
richmond-park/richmond-park-attractions/wildlife/deer-in-richmond-park [Accessed 1 September 2020].
Oberst, T., 2019. Untitled. [photograph].]
Using Figure 5, construct an identification key for the deer species found in London.
With reference to Figures 6(a), 6(b) and 6(c), predict how the ecosystem would be affected if the deer population in Richmond Park was not managed.
Figure 4(d): Example of a Coral Triangle marine food web