What are Ecosystems? (Cambridge (CIE) IGCSE Geography) : Revision Note

What are ecosystems?

• An ecosystem is a biological community of organisms that interact with each other and their physical environment

• Ecosystems vary in size and scale 

  • A garden pond is a small ecosystem

  • The Great Barrier Reef, Australia is thousands of square km in size and is a large scale ecosystem known as a biome

• Biotic organisms are living things, like animals, plants, fungi, and microorganisms

• The non-living are abiotic components of an ecosystem, such as temperature, light, water, and soil

• Species in an ecosystem are interdependent

  • This is because they rely on each other for food, shelter, pollination, and seed dispersal

  • This keeps the ecosystem community stable

• Changes in one component can impact other parts of the ecosystem

  • For instance, deforestation will impact the soil, biotic life, and climate

Characteristics of an ecosystem

• The abiotic factors of an area will determine the characteristics of an ecosystem

• The climate will influence the types of flora (plants) that can grow

  • This in turn will determine the type of food and habitat available for organisms to survive in the area

• Ecosystems have different levels of organisation, from individual organisms to populations (groups of the same species), communities (groups of different species), and the whole ecosystem

• Organisms compete for resources like light, space, water, food, breeding partners and territory

• Ecosystems recycle materials such as carbon, nitrogen and water through processes like photosynthesis, respiration, and decomposition