Practise SL questions on human impacts on resilience by tracing destabilizing pressures, protective actions and balanced ecological-system analysis.
Discuss the role of humans in the destabilization of ecological systems.
The following guide for using the markbands suggests certain features that may be offered in responses. The five headings coincide with the criteria given in each of the markbands (although "ESS terminology" has been conflated with "Understanding concepts"). This guide simply provides some possible inclusions and should not be seen as requisite or comprehensive. It outlines the kind of elements to look for when deciding on the appropriate markband and the specific mark within that band.
Answers may include:
- understanding concepts and terminology of steady state and dynamic equilibria, stability, resilience, tipping-points, diversity, storage size, productivity, negative/positive feedback, complexity, community interdependence/interaction, human impacts of overexploitation/unsustainable harvesting, pollution, habitat degradation/destruction, unsustainable development, etc
- breadth in addressing and linking factors that provide stability/resilience eg storage size, diversity, productivity, complexity, etc with human activities that either weaken/reduce them eg overfishing, intensive agriculture, C emissions/global warming, water/atmospheric pollution, deforestation, urbanisation, mining/resource extraction, etc or activities that strengthen/protect them eg legislation setting pollution limits/standards/fishing quotas, sustainable development schemes, alternative/renewable energies, conservation efforts/reserves, etc
- examples of specific negative impacts on stability of ecological systems e.g. overfishing reduces the storage size of targeted fish populations reducing their stability, C emissions lead to climate change that reduces primary productivity of systems, eutrophication will interfere with negative feedback loops in freshwater systems, atmospheric pollutants may eliminate sensitive species of lichen reducing diversity, etc and positive impacts on stability e.g. in-situ conservation protects complexity of relationships in system, agricultural techniques conserving soils maintain high productivity, etc
- balanced analysis of the extent to which human activities promote or prevent destabilisation of ecological systems with acknowledgement of relevant counter-arguments/alternative viewpoints.
- a conclusion that is consistent with, and supported by, analysis and examples given eg "The role of humans in destabilising ecological systems is very diverse, and with the current size and growth of population, the magnitude of that role is becoming immense, calling for urgent and wide-scale efforts to adopt a proactive role in re-stabilising those systems." NB This is only an example of a possible conclusion. Candidates' conclusions do not have to agree. Their value should be assessed simply according to the criteria given in the markband descriptors.
Please see markbands on page 20.