Strategies for Conserving Biodiversity (Cambridge International IGCSE Environmental Management)

Strategies for conserving biodiversity & genetic resources

• 'Biodiversity' means the variety of life on Earth

• Every species adds something important, from keeping soils healthy to pollinating crops

• When species disappear, ecosystems can struggle to support life

• This is why humans use a range of conservation strategies to protect species, habitats and the genetic information they carry

  • Genetic resources refer to the variety of genes within and between species, important for adaptation, food security and disease resistance

• Each strategy helps nature differently, and together they create a stronger safety net for the planet

Sustainable harvesting of wild plant and animal species

• Taking only a small amount of a species

  • This allows populations to reproduce fast enough to replace what is removed
  • This helps stop long-term decline

• Allowing harvesting seasons

  • Species can then breed at the right time of year without being disturbed
  • This supports healthier population growth

• Using quotas or size limits

  • Young individuals can stay in the ecosystem and continue the life cycle
  • This keeps food chains and food webs balanced

• Training local communities in safe harvesting methods so they can earn income without harming ecosystem health

Worked Example Define what is meant by ‘sustainable harvesting’.

[1 mark]

Answer

Sustainable harvesting means taking only a safe amount of a wild species so the population can replace itself and stay healthy over time. [1 mark]

Marking guidance

The command word 'define' requires providing the precise meaning of a term in a brief and clear statement.

Mark allocation

• 1 mark is awarded for a clear idea that harvesting does not reduce long-term population size.

Alternative content

• Taking a level that the species can naturally replace.
• Removing individuals without causing population decline.

Typical mistakes:

• Describing a method rather than the meaning.
• Forgetting to mention that the population remains sustainable.

Sustainable forestry

• Selective logging removes only certain trees

  • This minimises canopy loss and reduces disturbance to forest structure

• Leaving seed trees standing

  • This allows for natural reseeding of the forest
  • Which helps new generations of trees grow and maintain genetic diversity

• Planning logging tracks carefully

  • This reduces soil disturbance
  • Which protects the forest floor from erosion and nutrient loss

• Replanting trees after harvesting

  • The forest continues to supply timber, supports wildlife and stores carbon

National parks and reserves

• Setting aside protected land

  • The whole ecosystem can then function without activities like farming or mining
  • This allows species to live with minimal human pressure

• Offering safe habitats where threatened species can feed, breed and migrate freely

  • This improves their chances of survival

• Helping control visitor access so sensitive areas are shielded from damage

  • This protects ecosystems that cannot cope with heavy disturbance

• Providing centres for research and education allows people to learn how ecosystems work and why conservation matters

Wildlife corridors

• Connecting separate habitats allows animals to move between areas

  • This helps them find food, mates and new territories when conditions change

• Let species escape natural hazards like wildfires or droughts

  • This makes them more resilient to climate change

• Keeping populations genetically healthy

  • Allowing individuals from different groups to mix reduces the risk of inbreeding

• Allowing safe movement across roads or railways through bridges and tunnels lowers the danger of collisions with vehicles

Worked Example Explain how wildlife corridors help conserve biodiversity.

[2 marks]

Answer

Wildlife corridors let animals move safely between separate habitats, which helps them find food and mates more easily. [1] This movement mixes different groups of the same species, increasing genetic diversity and helping populations adapt and survive. [1]

Marking guidance

The command word 'explain' requires you to provide reasons or demonstrate cause-and- effect relationships.

Mark allocation

• 1 mark is awarded for identifying movement between habitats
• 2nd mark for genetic diversity or improved resilience.

Alternative content

• Corridors allow migration during climate change.
• Corridors reduce roadkill and accidents.
• Corridors help recolonise damaged habitats.

Typical mistakes:

• Only describing what a corridor is.
• Focusing on human benefits instead of biodiversity.

Seed banks

• Storing seeds in cold, dry conditions allows them to stay viable for many years

  • This creates a long-term backup for rare plants

• Protecting wild plant genes from threats like pests, diseases or climate change

  • Future farming options are kept open

• Allowing scientists to test how seeds germinate under different conditions

  • This helps to identify which plants might cope best with a warmer world

• Reintroduce plant species into the wild if local extinction happens

  • Letting conservationists help ecosystems recover

Zoos and captive breeding

• Providing **controlled environments **where endangered animals can breed safely without predators, poachers or habitat loss

• Help** increase population sizes**

  • This is particularly useful when numbers are too low to be self-sustaining in the wild

• Using studbooks to match breeding pairs carefully

  • This protects genetic diversity and avoids inbreeding problems

• Animal release preparation through training that builds natural behaviours that make it easier for them to live in the wild

Ecotourism

• Encouraging responsible travel

  • Visitors protect and respect the environment
  • Thereby, reducing harm to fragile ecosystems

• Bring money directly to local communities so they benefit from protecting wildlife rather than destroying habitats

• Funding conservation projects such as ranger patrols, habitat restoration and scientific research

• Raising awareness among tourists

  • This helps people understand why biodiversity matters and how they can help protect it

International cooperation against animal trade

• Countries are working together to track and stop illegal wildlife trafficking, making it harder for criminal networks to operate
• International cooperation includes treaties such as CITES (Convention on International Trade in Endangered Species)
• Sharing scientific information so nations can identify species under pressure and respond quickly
• Creating agreements that support the sustainable use of wildlife, helping reduce overexploitation
• Training customs officers and improving border checks to detect illegal products more effectively

Regulation of trade in vulnerable and endangered species

• Using international rules like CITES to control or ban trade in certain species

  • These rules help to reduce the number of animals or plants removed from the wild

• Requiring permits for legal trade

  • This allows authorities to monitor species numbers
  • Which ensures harvesting stays sustainable

• Helping consumer countries avoid buying products linked to wildlife decline

  • This reduces demand for illegal items

• Giving endangered species time to recover because fewer individuals are taken from natural habitats

Classifying organisms by threat level

• Sorting species into categories like 'threatened', 'endangered' or 'extinct' based on scientific data

  • This helps focus conservation work

• Showing which species need urgent action and which are stable

  • This guides how money and resources are used

• Updating lists regularly so changes in population size are tracked

  • This reveals whether conservation strategies are effective

• Raising public awareness about species at risk, encouraging support for protection efforts

Benefits & limitations of strategies for conserving biodiversity

Benefits

• Protecting species helps ecosystems stay stable because each species contributes to food webs, nutrient cycles and habitat structure
• Conserving genetic resources allows scientists to develop new crops that can resist drought, pests or diseases, improving future food security
• Sustainable harvesting lets communities earn income without destroying habitats, supporting long-term livelihoods
• Protected areas and wildlife corridors give species safe spaces to move, adapt and recover from shocks such as storms or fires
• Seed banks and captive breeding create safety nets for species that are close to extinction, offering second chances for recovery
• International trade laws reduce the pressure on heavily exploited species, helping populations grow again
• Ecotourism funds conservation and encourages people to value nature, increasing support for protection projects

Limitations

• Protected areas can be costly to manage, and without enough staff or money, illegal activities like poaching may still happen

• Captive breeding does not always prepare animals fully for life in the wild, and some may struggle to hunt, hide or find territory

• Wildlife corridors can be hard to build in crowded landscapes where roads, farms or towns block natural pathways

• Seed banks cannot store all plant types, especially those with delicate seeds that do not survive freezing or drying

• Sustainable harvesting requires ****strong monitoring and cooperation, which can be difficult in remote or low-income areas

• International agreements depend on countries enforcing the rules, and** weak enforcement** can reduce their impact

• Ecotourism can cause damage if too many visitors arrive or if rules are not followed, putting stress on sensitive habitats

  • Revenue is seasonal and can collapse during political instability or global crises (e.g., pandemics)

Worked Example Discuss the benefits and limitations of seed banks as a conservation strategy.

[4 marks]

Answer

Seed banks protect plant species by storing seeds safely so they can be replanted if wild populations disappear. [1] They help conserve a huge variety of genetic material, which is important for future farming and medicine. [1]

However, some plant species cannot be stored because their seeds do not survive freezing or drying, reducing how many species can be protected. **[1] **Seed banks also require high funding and careful management, so it can be difficult for poorer countries to run them effectively. [1]

Marking guidance

The command word 'discuss' requires you to provide both sides of an argument with supported points.

Mark allocation

• Up to** 2 marks for benefits **such as:

  • Storing seeds protects rare species
  • Maintains genetic diversity
  • Seeds can be used for reintroduction
  • Useful for crop research

• Up to** 2 marks for limitations** such as:

  • Not all seeds can be stored (recalcitrant seeds)
  • Seeds must be replaced regularly as viability decreases
  • High running costs and technical expertise required
  • No protection for animals or whole ecosystems

Alternative content

• Seed banks act as insurance against disasters like disease outbreaks.
• Storage conditions must be very precise; otherwise, seeds may die.
• Seed banks cannot protect plants that rely on specific soil fungi or pollinators.

Common mistakes

• Only giving benefits.
• Giving only limitations.
• Writing about zoos instead of seed banks.

Examiner tips

• Use the question’s words in your opening sentence to stay focused.
• Short, clear ideas are easier to mark and less likely to drift off-topic.