CAPE Environmental Science
Unit 1: The Ecological Perspective
Modules 1–3 Detailed Notes
Module 1: The Ecosystem
1.1 Characteristics of the Environment
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Environment includes:
o Abiotic factors: temperature, light, soil, water, pH, air.
o Biotic factors: living organisms and their interactions.
Types of Environments:
o Natural (e.g., forests, wetlands)
o Man-made (e.g., cities, farmlands)
Ecosystem: A unit formed by the interaction of a community of organisms with their
physical environment.
1.2 Structure and Function of Ecosystems
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Producers: Autotrophs (e.g., plants)
Consumers: Heterotrophs (e.g., herbivores, carnivores)
Decomposers: Break down dead material (e.g., fungi, bacteria)
Trophic Levels: Position in food chain (Producer → Consumer → Decomposer)
Food Chains & Webs: Represent energy/nutrient flow
1.3 Biogeochemical Cycles
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Water Cycle: evaporation → condensation → precipitation
Carbon Cycle: photosynthesis, respiration, fossil fuel use
Nitrogen Cycle: fixation, nitrification, assimilation, denitrification
Phosphorus Cycle: weathering, uptake, waste breakdown
1.4 Energy Flow
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Sunlight is the primary energy source
10% Rule: Only ~10% of energy is passed to next trophic level
Productivity:
o GPP: Total energy from photosynthesis
o NPP: Energy available after respiration (GPP - respiration)
Module 2: People and the Environment
2.1 Human Population and Demographics
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Population dynamics: birth rate, death rate, age structure
Carrying Capacity: Max sustainable population size
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Impacts of overpopulation: resource depletion, pollution
2.2 Cultural and Economic Influences
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Influence of traditions and technology on environmental use
Developed vs. Developing Nations: different environmental footprints
Consumption patterns influence sustainability
2.3 Human Impact on the Environment
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Key issues: deforestation, pollution, urbanization, biodiversity loss
Positive approaches: conservation, education, green technology
2.4 Sustainable Development
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Definition: Meeting needs without compromising future generations
Three Pillars: economy, environment, society
Key principles: intergenerational equity, stakeholder involvement
Module 3: Sustainable Use of Natural Resources
3.1 Types and Classification of Resources
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Renewable: replenished by nature (e.g., solar energy, wind, forests, freshwater)
Non-renewable: limited supply, not replenished on human timescales (e.g., fossil
fuels, metals, minerals)
Continuous: naturally ongoing and not depleted by human use (e.g., sunlight, tides,
geothermal energy)
Examples:
o Renewable: timber (with proper management), fish (if not overharvested)
o Non-renewable: coal, oil, natural gas, uranium
3.2 Resource Use and Management
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Sustainable practices:
o Crop rotation: maintains soil fertility
o Agroforestry: integrates trees with crops
o Afforestation and reforestation: restoring forest cover
o Sustainable fisheries: quotas, seasonal bans, gear restrictions
o Water conservation: rainwater harvesting, efficient irrigation (e.g., drip
systems)
Tragedy of the Commons:
o Occurs when individuals overexploit shared resources for personal gain
o Example: overfishing in international waters
3.3 Environmental Legislation and Policies
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International Agreements:
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CITES: protects endangered species from international trade
Kyoto Protocol & Paris Agreement: address climate change
UNCLOS: governs use of oceans
National Regulations:
o Environmental Protection Acts
o Protected area designation (e.g., marine reserves, national parks)
o Waste management laws (e.g., solid waste and hazardous waste control)
Enforcement Tools:
o Fines, permits, environmental monitoring, public awareness campaigns
3.4 Economic Tools for Sustainability
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Environmental Impact Assessment (EIA):
o Mandatory for large-scale development projects
o Identifies and mitigates potential environmental harm
Cost-Benefit Analysis (CBA):
o Compares economic returns to environmental/social costs
o Aids decision-making in resource use
Incentives for sustainability:
o Green subsidies: e.g., for solar panels or electric vehicles
o Carbon credits: tradeable permits to emit CO₂
o Eco-labels: help consumers identify sustainable products
o Polluter Pays Principle: those responsible for pollution bear the costs of
managing it
End of Unit 1 Notes