Part 3: Case Study

1. Case Review

The purpose of this activity is to ensure that students have a thorough understanding of the case. This is accomplished in class by review of their Assignment Question answers and their comments during the Discussion Questions. Students should demonstrate knowledge of the sustainability issues involved in the case and the strategies being used to address the issues.


    • Review Core Reading and Assignment Questions.
    • Inform the students about which Assignment Questions they should answer as part of their preparation for class. You can assign different students to report to the class on the answers to different questions. You can also designate students to serve as discussion leaders and provide each with a Discussion Question in advance of the class. Having multiple students responsible for the same Discussion Question will facilitate the small group discussions.

In Class

      •  Have students report on the Assignment Questions and assist the discussion groups as  they consider each of the Discussion Questions. Have someone from each group report their group’s opinions to the whole class.

Discussion Questions

  1. Why do environmental programs prioritize certain types of natural areas for preservation? In light of the issue readings on the importance of biodiversity, how does the fynbos fit this profile?
  2. The South African Constitution considers the right to clean water a civil right. Recalling the issue readings on the importance of sanitation to health, do you agree with this assessment? Why or why not?

Core Reading

  1. Working for Water, A South African Sustainability Case: Introduction, Background, Section A, and Section B (19 pages)

Assignment Questions

  1. Explain the concept of ecosystem services. How does this concept relate to efforts to preserve native ecosystems in South Africa? What are examples in the case of ecosystem services provided by the fynbos?

    • Ecosystem services are a way of measuring the human value of natural resources in economic terms. The concept is relevant in the case study because it justifies the high cost incurred to protect the native ecosystems. Ecosystem services include sustaining biodiversity, regulation of the hydrological cycle, and protection from natural disasters such as floods and fires.

  2. In South Africa, how much water do invasive alien species currently consume above what would be consumed by native vegetation? What percentage of run-off water can be kept from being lost by controlling invasive alien species in South Africa?

    • Invasive aliens currently consume 3.3 billion cubic meters of water per year beyond what native plants would require. This is 6.7% of total annual runoff now, and could eventually reach 16% if invasive aliens are allowed to spread.

  3. How much more soil erosion do invasive pine forests create after fires compared to native fynbos?

    • 20 to 60 times.

  4. For Black Wattle, there are two possible mechanisms for controlling the invasion: a combination of physical and chemical control or biological control. What are the advantages and disadvantages of each method?

    • Physical and chemical control:

    1. Advantages: does not disturb commercial plantations; creates jobs in the short term
    2. Disadvantages: high cost; potential danger associated with using chemicals or controlled burning; need for continual follow-up operations

    • Biological control:

    1. Advantages: lower cost in the long term; does not require follow-up
    2. Disadvantages: high initial research cost; threat to commercial plantations

    *Students should understand that for Black Wattle, the methods are complementary, since biological control can limit the spread, but not independently control the invasion.

  5. Ignoring the social benefits and focusing only on the environmental results, is Working for Water cost-effective? Why or why not?

    • Yes. Even from the narrow view of water, controlling alien plants is cheaper in the long term than dealing with the consequences of water scarcity. The program also provides spillover benefits in education, empowerment, health training for employees, and overall ecosystem health for the environment.