The Living World

    OCR
    GCSE

    This module necessitates a rigorous analysis of ecosystems as open systems, defined by the complex interdependence of biotic and abiotic components. Candidates must examine energy flows (food webs, trophic levels) and nutrient cycling (Gersmehl diagrams) across varying scales, from local small-scale ecosystems to global biomes. The study demands critical evaluation of human impacts—specifically deforestation, desertification, and climate change—alongside the assessment of sustainable management strategies. Proficiency in interpreting spatial distributions based on latitudinal climate controls is essential.

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    Objectives
    4
    Exam Tips
    3
    Pitfalls
    3
    Key Terms
    4
    Mark Points

    What You Need to Demonstrate

    Key skills and knowledge for this topic

    • Credit identification of specific interdependence links (e.g., nutrient cycling between biomass, litter, and soil).
    • Award marks for precise distinction between abiotic (climate, soil, water) and biotic (flora, fauna) components.
    • Responses must apply specific case study data (e.g., Amazonia or Antarctica) rather than generic rainforest/polar descriptions.
    • High-level responses must evaluate the efficacy of management strategies (e.g., debt-for-nature swaps vs. international treaties) rather than simply listing them.

    Example Examiner Feedback

    Real feedback patterns examiners use when marking

    • "You have described the threat; now explain the specific impact on the nutrient cycle."
    • "Differentiate clearly between the 'goods' and 'services' provided by the ecosystem."
    • "Support your judgment on the success of the Antarctic Treaty with specific evidence of its limitations."
    • "Link the physical adaptation directly to the climatic constraint (e.g., buttress roots for stability in shallow soil)."

    Marking Points

    Key points examiners look for in your answers

    • Credit identification of specific interdependence links (e.g., nutrient cycling between biomass, litter, and soil).
    • Award marks for precise distinction between abiotic (climate, soil, water) and biotic (flora, fauna) components.
    • Responses must apply specific case study data (e.g., Amazonia or Antarctica) rather than generic rainforest/polar descriptions.
    • High-level responses must evaluate the efficacy of management strategies (e.g., debt-for-nature swaps vs. international treaties) rather than simply listing them.

    Examiner Tips

    Expert advice for maximising your marks

    • 💡When assessing management, categorize strategies into 'local' (e.g., selective logging) and 'global' (e.g., CITES, Antarctic Treaty).
    • 💡Use the 'So what?' rule to develop chains of reasoning: Deforestation -> Soil erosion -> Loss of nutrients -> Failure of regrowth.
    • 💡Integrate climate graph data (temperature range, precipitation totals) directly into descriptions of biome distribution.
    • 💡Ensure the small-scale ecosystem example is distinct from the global case studies.

    Common Mistakes

    Pitfalls to avoid in your exam answers

    • Confusing 'weather' with 'climate' when describing biome characteristics.
    • Failing to distinguish between 'goods' (tangible products) and 'services' (processes like carbon sequestration) provided by ecosystems.
    • Describing human impacts generically (e.g., 'pollution') without specifying the mechanism (e.g., 'eutrophication' or 'bioaccumulation').

    Study Guide Available

    Comprehensive revision notes & examples

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    Key Terminology

    Essential terms to know

    Likely Command Words

    How questions on this topic are typically asked

    Describe
    Explain
    Assess
    Evaluate
    Calculate
    To what extent

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