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

• What is an ecosystem?
• 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.

Tropical rainforest ecosystems have a range of distinctive characteristics:

• The physical characteristics of a tropical rainforest – vegetation, climate & the nutrient cycle
• Interdependence in the tropical rainforest
• How plants and animals adapt to the physical conditions.
• Biodiversity issues in the tropical rainforest

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
  Amazon Rainforest Case Study 
  Malaysian Rainforest Case Study
• impacts of deforestation – economic development, soil erosion, contribution to climate change.
  Amazon Rainforest Case Study
  Malaysian Rainforest Case Study

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, and debt reduction.

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

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
• Case studies: Sahara Desert – Western Desert – Thar Desert

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

Causes of desertification – climate change, population growth, removal of fuelwood, 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.

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

• The location and physical characteristics of a cold environment.
• The interdependence of climate, permafrost, soils, plants, animals and people.
• How plants and animals adapt to physical conditions.
• Issues related to biodiversity.

Development of cold environments creates opportunities and challenges:

A case study of a cold environment (Alaska) 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.

A case study of a cold environment (Svalbard) 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, the role of governments, international agreements and conservation groups