Ecosystem services and biodiversity loss: HSC Geography 2022 Focus Area

Note: This page is part of the HSC Geography 11-12 (2022) syllabus, first examined in HSC 2025. The legacy 2009 syllabus "Biophysical Interactions" and "Ecosystems at Risk" content is preserved in sibling folders.

What this sub-topic is asking

Ecosystems and Global Biodiversity asks you to investigate ecosystems as systems, analyse the drivers of biodiversity loss, and evaluate management strategies. The strongest framework is ecosystem services: it shows why biodiversity matters in economic, social and environmental terms; the IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) is the canonical authority.

The answer

Ecosystem services

The Millennium Ecosystem Assessment (2005) and subsequent IPBES reports group ecosystem services into four categories:

Provisioning services

Material goods provided by ecosystems: food (fish, game, crops), fresh water, timber, fibre, medicines, fuel.

Regulating services

Ecosystem processes that regulate environmental conditions: climate regulation (forests as carbon sinks), water purification (wetlands, riparian zones), pollination (insects on crops), disease regulation (predator-prey balances), flood and erosion control (mangroves, coastal vegetation).

Cultural services

Non-material benefits: spiritual significance, recreation, aesthetic value, sense of place, ecotourism revenue, scientific research, traditional ecological knowledge.

Supporting services

Underlying processes that enable the other categories: nutrient cycling, soil formation, photosynthesis, the water cycle.

Strong geography responses use ecosystem services as the framework for why biodiversity loss is a sustainability challenge: the loss is not just aesthetic, it removes provisioning, regulating and cultural value with measurable human consequence.

Drivers of biodiversity loss (the five drivers)

IPBES identifies five direct drivers of biodiversity loss globally, in approximate order of current impact:

1. Land and sea use change. Deforestation, agricultural expansion, urbanisation, mining, fishing gear that alters seafloor. The single largest current driver on land.
2. Direct exploitation. Overfishing, hunting, poaching, logging beyond regeneration rates. The dominant driver in marine ecosystems.
3. Climate change. Temperature-driven range shifts, mass coral bleaching, phenological mismatches, ocean acidification. A growing driver, projected to dominate by mid-century.
4. Pollution. Plastic pollution in marine systems, agricultural runoff (nitrogen, phosphorus, pesticides), heavy metals, light and noise pollution.
5. Invasive species. Introduced species outcompete or prey on natives; particularly devastating on islands (cane toads in Australia, brown tree snakes on Guam, rats on countless oceanic islands).

Indirect drivers: population growth, consumption patterns, technology shifts, governance failures, value systems.

Scale of biodiversity loss

• Approximately 1 million plant and animal species face extinction within decades (IPBES Global Assessment 2019).
• Global vertebrate populations have declined approximately 69 percent on average since 1970 (WWF Living Planet Index 2022).
• Insect biomass has fallen substantially in monitored regions; estimates vary widely but Germany's flying-insect biomass studies showed approximately 75 percent decline over 27 years.
• Australia has the world's highest rate of mammal extinction in modern times; over 30 mammal species lost since European settlement.

Conservation strategies

Protected areas

National parks, marine parks, biosphere reserves. Aichi Biodiversity Targets (2010) aimed for 17 percent terrestrial and 10 percent marine protection by 2020; the Kunming-Montreal Global Biodiversity Framework (2022) sets a "30 by 30" target (30 percent of land and ocean protected by 2030). Australia's National Reserve System is approximately 22 percent of land area; Marine Parks cover approximately 45 percent of Australian waters.

Ecological restoration

Bringing degraded ecosystems back toward a reference state. Examples: Loess Plateau restoration in China; Iberian rewilding; Australian threatened-species recovery plans.

Global agreements

• Convention on Biological Diversity (CBD, 1992). Parent treaty; sets the global biodiversity framework. The Kunming-Montreal Framework (COP15, 2022) is its current implementation plan.
• CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora, 1975). Controls cross-border trade in threatened species. Trade bans on elephant ivory, rhino horn, certain timbers and orchids.
• Ramsar Convention (1971). Protects wetlands of international importance. Australia has approximately 65 Ramsar-listed wetlands.

Indigenous-led conservation. Indigenous Protected Areas in Australia now cover approximately 50 percent of the National Reserve System. Evidence shows Indigenous-managed land often has biodiversity outcomes equal to or better than government-managed parks, at lower cost.

Market-based. Payments for ecosystem services (e.g. REDD+ for forest carbon), biodiversity offsets, certification schemes (Marine Stewardship Council, FSC for timber).

Examples in context

Example 1. Kunming-Montreal Global Biodiversity Framework (COP15, December 2022). The Convention on Biological Diversity adopted the Kunming-Montreal Framework with 23 targets, including the headline "30 by 30" target. Australia signed and committed to expanding the National Reserve System toward the 30 percent target by 2030 and protecting 30 percent of Australian waters. Implementation requires state, territory and Indigenous partnerships. A strong response uses this to demonstrate that global biodiversity governance produces commitments, but country-level implementation determines whether commitments translate into protection.

Example 2. Amazon deforestation and the global carbon-biodiversity link. Brazil's Legal Amazon lost approximately 11 600 km2 of forest in 2022 (highest in 15 years at the time); deforestation rates fell approximately 50 percent in 2023 under renewed enforcement. The Amazon holds approximately 10 percent of known terrestrial biodiversity and stores approximately 150-200 billion tonnes of carbon. Deforestation simultaneously drives biodiversity loss and accelerates climate change (the second of the five drivers feeding the third). The case demonstrates the interconnection geographical concept and shows why ecosystem and climate policy must be integrated.

Try this

Q1. Identify the four categories of ecosystem services with one example of each. [4 marks]

• Cue. Provisioning (fish), regulating (pollination), cultural (ecotourism), supporting (nutrient cycling).

Q2. Analyse the five drivers of global biodiversity loss, with an indication of the dominant driver for land and for marine ecosystems. [6 marks]

• Cue. Land use change, direct exploitation, climate change, pollution, invasive species. Land-use change dominates on land; direct exploitation dominates in oceans; climate change is rising for reefs and polar systems.

Q3. Evaluate the effectiveness of global agreements (CBD / Kunming-Montreal, CITES) in addressing biodiversity loss. [8 marks]

• Cue. Strengths: shared framework, peer accountability, area-based commitments. Weaknesses: voluntary, missed Aichi targets, implementation depends on national capacity, climate change is the dominant rising driver and is largely addressed in a separate treaty regime (UNFCCC / Paris). Reach a calibrated judgement; don't pretend any single agreement is sufficient.