UPSC Prelims 2012 Q94: Environment & Ecology – Ecosystems & Ecology Concepts
The Millennium Ecosystem Assessment describes the following major categories of
ecosystem services - provisioning, supporting, regulating, preserving and cultural.
Which one of the following is a supporting service?
- (a) Production of food and water
- (b) Control of climate and disease
- (c) Nutrient cycling and crop pollination
- (d) Maintenance of diversity
Answer: (c) Nutrient cycling and crop pollination
Explanation
Ecosystem services in the Millennium Ecosystem Assessment
The Millennium Ecosystem Assessment (2005) grouped the benefits people get from nature.
Supporting services are the basic natural processes that make all other services possible.
| Option | Category | Verdict |
|---|---|---|
| (a) Production of food and water | Provisioning | Incorrect |
| (b) Control of climate and disease | Regulating | Incorrect |
| (c) Nutrient cycling and crop pollination | Supporting | Correct |
| (d) Maintenance of diversity | Not listed as a supporting service here | Incorrect |
The categories:
| Category | Examples |
|---|---|
| Provisioning | Food, fresh water, timber, fibre, fuel |
| Regulating | Climate control, flood control, disease control, water purification |
| Cultural | Recreation, spiritual and aesthetic value |
| Supporting | Nutrient cycling, soil formation, primary production |
Answer: (c) Nutrient cycling and crop pollination.
Why each option is right or wrong
- (a) Incorrect. Production of food and water is a provisioning service.
- (b) Incorrect. Control of climate and disease is a regulating service.
- (c) CORRECT. Nutrient cycling is the standard example of a supporting service.
- (d) Incorrect. Maintenance of diversity is not the supporting service named in the Assessment.
Key point
Millennium Ecosystem Assessment (2005): provisioning (food, water), regulating (climate, disease), cultural (recreation), supporting (nutrient cycling, soil formation, primary production).
Remember
Supporting = nutrient cycling and soil formation.
Common mistakes
- Mixing up regulating and supporting services.
- Choosing food and water, which are goods we take directly, so provisioning.
- Being put off by 'preserving' in the question; it is not a standard category.
Exam tip
Supporting services work in the background. Nutrient cycling and soil formation are the two to remember.
Sources
- Millennium Ecosystem Assessment (2005) — Ecosystems and Human Well-being: Synthesis
- NCERT Class XII — Biology, Ch 14 (Ecosystem: Ecosystem Services)