The Living World: Key Ideas (AQA GCSE Geography): Revision Note

3.1.2.1

Ecosystems exist at a range of scales and involve the interaction between biotic and abiotic components.

• An example of a small scale UK ecosystem to illustrate the concept of interrelationships within a natural system, an understanding of producers, consumers, decomposers, food chain, food web and nutrient cycling.

• The balance between components. The impact on the ecosystem of changing one component.

• An overview of the distribution and characteristics of large-scale natural global ecosystems.

3.1.2.2

Tropical rainforest ecosystems have a range of distinctive characteristics.

• The physical characteristics of a tropical rainforest.

• The interdependence of climate, water, soils, plants, animals and people.

• How plants and animals adapt to the physical conditions.

• Issues related to biodiversity

Deforestation has economic and environmental impacts.

• Changing rates of deforestation.

• A case study of a tropical rainforest to illustrate:

  • causes of deforestation – subsistence and commercial farming, logging, road building, mineral extraction, energy development, settlement, population growth

  • impacts of deforestation – economic development, soil erosion, contribution to climate change.

Tropical rainforests need to be managed to be sustainable.

• Value of tropical rainforests to people and the environment.Strategies used to manage the rainforest sustainably – selective logging and replanting, conservation and education, ecotourism and international agreements about the use of tropical hardwoods, debt reduction.

3.1.2.3

Hot desert ecosystems have a range of distinctive characteristics.

• The physical characteristics of a hot desert.

• The interdependence of climate, water, soils, plants, animals and people.

• How plants and animals adapt to the physical conditions. Issues related to biodiversity.

Development of hot desert environments creates opportunities and challenges.

• A case study of a hot desert to illustrate:

  • development opportunities in hot desert environments: mineral extraction, energy, farming, tourism

  • challenges of developing hot desert environments: extreme temperatures, water supply, inaccessibility.

Areas on the fringe of hot deserts are at risk of desertification.

• Causes of desertification – climate change, population growth, removal of fuel wood, overgrazing, over-cultivation and soil erosion.

• Strategies used to reduce the risk of desertification – water and soil management, tree planting and use of appropriate technology.

3.1.2.4

Cold environments (polar and tundra) have a range of distinctive characteristics.

• The physical characteristics of a cold environment.

• The interdependence of climate, permafrost, soils, plants, animals and people.

• How plants and animals adapt to the physical conditions. Issues related to biodiversity.

Development of cold environments creates opportunities and challenges.

• A case study of a cold environment to illustrate:

• development opportunities in cold environments: mineral extraction, energy, fishing and tourism

• challenges of developing cold environments: extreme temperature, inaccessibility, provision of buildings and infrastructure.

Cold environments are at risk from economic development.

• The value of cold environments as wilderness areas and why these fragile environments should be protected.

• Strategies used to balance the needs of economic development and conservation in cold environments – use of technology, role of governments, international agreements and conservation groups.