Paper 1 Preparation » Ecosystem Questions

What you'll learn this session

Study time: 30 minutes

Understanding of ecosystem components and interactions
Knowledge of tropical rainforest and savanna grassland ecosystems
Ability to explain climate, vegetation and adaptations in ecosystems
Skills to analyse ecosystem management and conservation
Techniques to tackle ecosystem questions in Paper 1

Introduction to Ecosystems

Ecosystems are dynamic communities where living organisms interact with each other and their physical environment. Paper 1 of the Cambridge iGCSE Geography exam frequently tests your understanding of ecosystems, particularly tropical rainforests and savanna grasslands.

Key Definitions:

Ecosystem: A community of living organisms interacting with each other and their physical environment.
Biome: A large naturally occurring community of flora and fauna occupying a major habitat.
Food chain: The sequence of organisms through which energy is transferred in the form of food.
Biodiversity: The variety of plant and animal life in a particular habitat.

🌍 Ecosystem Components

Every ecosystem consists of:

Abiotic components: Non-living factors like climate, soil, water and sunlight
Biotic components: Living organisms including producers (plants), consumers (animals) and decomposers (fungi and bacteria)

⚖️ Ecosystem Balance

Ecosystems maintain balance through:

Energy flow: From producers to consumers
Nutrient cycling: Recycling of nutrients through decomposition
Adaptation: Species evolving to suit their environment

Tropical Rainforest Ecosystem

Tropical rainforests are found near the equator (between 23.5°N and 23.5°S) and are characterised by high rainfall, temperature and biodiversity. They're a common focus in Paper 1 questions.

Climate and Structure

Understanding the climate and structure of rainforests is essential for exam questions that ask you to explain the relationship between climate and vegetation.

🌡️ Climate

Temperature: 27-32°C year-round
Rainfall: 2000-3000mm annually
High humidity (80%+)
Little seasonal variation

🌴 Structure

Emergent layer (tallest trees)
Canopy (dense layer of leaves)
Understorey (smaller trees)
Shrub layer (bushes, ferns)
Forest floor (dark, sparse vegetation)

🦋 Biodiversity

50-70% of Earth's species
One hectare may contain 300+ tree species
Rich in medicinal plants
Home to indigenous communities

Plant and Animal Adaptations

Exam questions often ask how organisms have adapted to survive in rainforest conditions. Remember these key adaptations:

🌱 Plant Adaptations

Drip tips: Leaves shaped to shed water quickly to prevent fungal growth
Buttress roots: Wide, shallow roots that provide stability in shallow soils
Lianas: Woody vines that climb trees to reach sunlight
Epiphytes: Plants growing on other plants to access light without reaching the ground

🐒 Animal Adaptations

Camouflage: Patterns and colours that blend with surroundings
Prehensile tails: Used by monkeys for gripping branches
Loud calls: Birds and monkeys communicate over distances
Nocturnal behaviour: Many animals are active at night to avoid heat

Case Study Focus: Amazon Rainforest

The Amazon rainforest covers 5.5 million km² across nine countries in South America, with 60% in Brazil. It contains:

10% of known species on Earth
2.5 million insect species
40,000 plant species
2,200 fish species
1,300 bird species

Threats include deforestation for cattle ranching, soy farming, logging and mining. Since 1970, about 20% of the Amazon has been cleared.

Savanna Grassland Ecosystem

Savanna grasslands are tropical grasslands with scattered trees, found between rainforests and deserts. They experience distinct wet and dry seasons and are home to many of Africa's iconic wildlife.

Climate and Characteristics

Savanna questions often focus on the seasonal climate and how it affects vegetation patterns.

☀️ Climate

Temperature: 20-30°C year-round
Rainfall: 500-1500mm annually
Wet season: 6-8 months
Dry season: 4-6 months with little rain

🌾 Vegetation

Grasses: Dominant vegetation, growing up to 3m tall
Trees: Scattered, drought-resistant species like acacia
Tree density: Increases near water sources
Fire adaptation: Plants evolved to survive regular fires

Adaptations in the Savanna

Exam questions may ask you to explain how plants and animals survive the challenging savanna conditions:

🌳 Plant Adaptations

Deep roots: To access groundwater during dry seasons
Thick bark: Protection against seasonal fires
Small leaves: Reduce water loss through transpiration
Seasonal growth: Growing during wet season, dormant in dry season

🦁 Animal Adaptations

Migration: Following rainfall patterns to find food and water
Camouflage: Blending with grass colours
Nocturnal behaviour: Avoiding daytime heat
Efficient water use: Some animals can survive without drinking for long periods

Case Study Focus: Serengeti Ecosystem

The Serengeti ecosystem spans 30,000 km² across Tanzania and Kenya and features:

The Great Migration: 1.5 million wildebeest and 200,000 zebras migrate annually
70+ large mammal species and 500+ bird species
Protected areas including Serengeti National Park and Maasai Mara Reserve
Challenges from poaching, climate change and human population growth

Ecosystem Management and Conservation

Paper 1 often includes questions about sustainable management and conservation of ecosystems. Be prepared to discuss:

🛡️ Conservation Strategies

Protected areas: National parks and reserves
Ecotourism: Sustainable tourism that supports conservation
Sustainable forestry: Selective logging and reforestation
Community involvement: Engaging local people in conservation

⚠️ Threats to Ecosystems

Deforestation: For agriculture, logging and mining
Climate change: Altering rainfall patterns and temperatures
Poaching: Illegal hunting of wildlife
Habitat fragmentation: Breaking habitats into isolated patches

Exam Technique for Ecosystem Questions

To excel in Paper 1 ecosystem questions, follow these tips:

Question Types

Description questions: Describe the climate/vegetation of an ecosystem
Explanation questions: Explain how plants/animals have adapted
Case study questions: Discuss management or threats to a specific ecosystem
Comparison questions: Compare two ecosystems (often rainforest vs savanna)

Answering Strategies

Use specific terminology (e.g., "buttress roots" rather than "big roots")
Include specific data and examples (temperatures, rainfall amounts)
For case studies, name specific locations (e.g., "Amazon Rainforest in Brazil")
Explain processes fully (e.g., how drip tips help plants survive)
Use diagrams where appropriate to show ecosystem structure

Exam Practice Question

Question: "Explain how vegetation has adapted to the climate of the tropical rainforest." [6 marks]

Model Answer Structure:

Briefly describe the climate (high rainfall, temperature, humidity)
Explain 3-4 adaptations with clear links to climate conditions:
- Drip tips on leaves to shed heavy rainfall
- Buttress roots for stability in shallow, waterlogged soil
- Smooth, thin bark as protection isn't needed against cold
- Epiphytes growing on trees to reach sunlight in dense canopy
Include a specific example (e.g., "In the Amazon rainforest, trees like the kapok can grow over 50m tall with buttress roots spreading 10m from the trunk")

🧠 Test Your Knowledge!