Key Idea: Most marks in topic 7.1 come from ecosystem services, how the value of resources changes and natural capital as a perspective. Then learn how to manage natural capital sustainably.
1. Ecosystem services (most marks)
- Provisioning: food, timber, water. Regulating: flood control, pollination, carbon storage.
- Supporting: soil, nutrient cycling, habitat. Cultural: recreation, beauty, spiritual value.
- Lose the ecosystem, lose the service: after clearing upstream forest, the Yangtze flooded badly in 1998.
2. Value changes over time
- Value depends on technology, culture and demand, so it is dynamic.
- Lithium rose from about US$8,000 a tonne (2021) to about US$80,000 (2022), then fell.
- Whales were worth meat and oil; since the 1986 whaling ban, whale watching earns more.
3. Natural capital as a perspective
- 'Natural capital' and 'natural income' treat nature as an economic stock that yields goods and services.
- Pricing nature can protect it: New York City saved its Catskill forests instead of building a filter plant.
- Other views give nature rights: Ecuador (2008), and New Zealand's Whanganui River (2017).
How it is examined:
| Question | How to score |
|---|---|
| [1] to [2] Identify an ecosystem service | Name the service and its type: 'flood control, regulating'. |
| [2] to [4] Outline how a resource's value has changed | Name the cause: technology, demand or culture, with dates. |
| [4] Explain how losing an ecosystem harms people | Ecosystem lost, service lost, the effect on people. |
| [7] Explain how natural capital can be managed sustainably | Harvest no faster than natural income; quotas, protection. |
| [9] Discuss natural capital as a way of seeing nature | Helps decisions, but misses intrinsic and cultural value. |
Key terms, one line each:
| Term | In one line |
|---|---|
| Natural capital | the stock of natural resources on Earth, such as forests, soils and fish |
| Natural income | the yield of goods and services that natural capital gives each year |
| Ecosystem services | the benefits people get from ecosystems, such as pollination and clean water |
| Renewable resource | a resource that is replaced by natural processes within a human lifetime |
| Intrinsic value | value a thing has in itself, whether or not people use it |
Last-minute check: answer, then tap to see.
Name the four types of ecosystem service. Provisioning, regulating, supporting and cultural.
Why did the Yangtze flood so badly in 1998? Upstream forest was cleared, so less water was held back.
Give one cause of a resource gaining value. New technology: lithium became valuable for batteries.
When is harvesting sustainable? When you take no more than the natural income, leaving the capital.
Along many tropical coasts, mangrove forests are being cleared for shrimp farms. Explain how losing mangroves reduces the ecosystem services people get.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Exam tips
- Name each ecosystem service and say which type it is.
- For changing value, give the cause and a dated example, such as lithium or whales.
- In a [9] on natural capital, give a strength, a limit and another view, then a judgement.
- Sustainable use means living off the natural income, not the capital.