VCE Environmental Science (Year 12) · Unit 3 — Ecosystems and Processes and Human Impacts · 16m read

Biodiversity as a Resource — Values and Ecosystem Services

Why should anyone care if a frog species disappears? Unit 3 begins by asking what biodiversity is worth — to ecosystems, economies, cultures and in its own right. These values are the foundation for every management decision you will evaluate later.

Learning objective: Explain the levels of biodiversity and the values and ecosystem services it provides.

By the end of this lesson you can:

• I can distinguish genetic, species and ecosystem diversity.
• I can classify values of biodiversity (intrinsic, economic, cultural, ecological).
• I can explain ecosystem services with examples.

Biodiversity is nature's bank account. Ecosystem services — clean water, pollination, climate regulation — are the interest. Spend the capital (species) and the interest disappears.

Levels and values of biodiversity

LEVELS OF BIODIVERSITY:
• GENETIC — variation of genes within a species; helps populations adapt.
• SPECIES — the number and relative abundance of species.
• ECOSYSTEM — the variety of habitats, communities and processes.

VALUES:
• INTRINSIC — biodiversity has value in itself, regardless of use.
• ECONOMIC (direct) — food, timber, fibre, medicines, tourism.
• ECOLOGICAL (indirect) — roles in food webs, nutrient cycling, stability.
• SOCIAL AND CULTURAL — recreation, spiritual and cultural significance, including Aboriginal and Torres Strait Islander connection to Country.

ECOSYSTEM SERVICES:
• PROVISIONING — food, fresh water, wood, medicines.
• REGULATING — pollination, climate regulation, flood control, water purification.
• SUPPORTING — soil formation, nutrient cycling, primary production.
• CULTURAL — recreation, education, spiritual value.

WHY DIVERSITY MATTERS:
• More diverse ecosystems tend to be more RESILIENT — better able to resist and recover from disturbance.

Quick reference

| Service | Example |
|---|---|
| Provisioning | Food, timber, medicines |
| Regulating | Pollination, water purification |
| Supporting | Nutrient cycling, soil formation |
| Cultural | Recreation, spiritual value |
| Values | Intrinsic and instrumental |

Key ideas at a glance

• Intrinsic vs instrumental value: Value in itself vs usefulness.
• Ecosystem services: Four categories.
• Genetic diversity: Resilience.
• First Nations knowledge: Caring for Country.

Worked example (Medium)

Classify each as provisioning, regulating, supporting or cultural: (a) mangroves reducing storm surge, (b) a fishery, (c) bees pollinating crops, (d) bushwalking.

1. (a). Regulating — reduces flood and storm damage.
2. (b). Provisioning — provides food.
3. (c). Regulating — pollination.
4. (d). Cultural — recreation.

Answer: (a) regulating (b) provisioning (c) regulating (d) cultural

Common mistakes

• Equating biodiversity with species count only It includes genetic and ecosystem diversity. Fix: Refer to all three levels.
• Confusing supporting and regulating services Supporting services underpin all others. Fix: Supporting = foundations (soil, nutrient cycling); regulating = control of processes.

Bees and your breakfast

A large share of food crops benefit from animal pollination. Losing pollinators would make many fruits and nuts scarcer and pricier.

Pollination is an ecosystem service with enormous economic value — usually "free".

Practice questions

1. Genetic diversity within a species is important mainly because it:

   1. Increases the number of species
   2. Allows the population to adapt to change
   3. Reduces competition
   4. Prevents mutation

   (1 marks)

Summary

• Genetic, species and ecosystem diversity.
• Values: intrinsic, economic, ecological, cultural.
• Ecosystem services: provisioning, regulating, supporting, cultural.