Ecosystems

• What is an ecosystem?

  A natural system where a community of plants and animals interact with each other.
• Three organisms of an ecosystem

  Producer - Organisms that convert energy from the environment into sugars

  Consumer - Organisms that receive energy from consuming living organisms

  Decomposers - Break down organic material and release the nutrients of the organic material into the soil
• Food Chains

  Shows how producers and consumers interact within an ecosystem

  
• Food Webs

  Interactions within ecosystems are complex. These complex relationships can be shown through a food web illustrating how multiple producers and consumers interact

  
• What is nutrient cycling?

  Animals and plants die and decomposers break up their organic matter into nutrients which are put back into the soil.

  
• How does change affect an ecosystem?

  Abrupt changes can throw off the ecosystem's balance and alter it.

  Some include:

  Introduction of new species - creates competition for space and food. Can either act as a predator, decreasing populations or as prey increasing the populations of those eating them

  Introduction of a disease - can devastate both plant and animal populations, changes in population size could affect food chains
• Eutrophication


  Changes to nutrient levels in freshwater ecosystems. Occurs when the environment becomes enriched with nutrients, increasing the amount of plant and algae growth which stops light from penetrating lower down meaning plants cannot photosynthesise. They produce no oxygen and oxygen-depleted waters cannot support aquatic life as there is no oxygen for respiration
• Global Ecosystems

  Also are known as biomes which are large scale ecosystems which are found around the world categorised by similar environmental characteristics. Usually occur near latitudinal belts which are areas of similar climates.
• Epping Forest

  Producers: fungi, trees (Maple, Ash and Oak)

  Primary consumers: worms, beetles, snails

  Secondary consumers: foxes, badgers, owls