Ecosystems

• What is an Ecosystem

  An ecosystem is a natural system made up of plants, animals and the environment
• Biotic

  living features such as plants and fish
• Abiotic

  Non-living environmental factors e.g. climate, soil, water, temperature, light
• small scale ecosystem

  a pond, hedgerow or woodland
• global scale ecosystem

  tropical rainforest or deciduous woodland. They are called biomes
• Producer

  Producers convert energy from the environment (sunlight) into sugars (glucose). e.g. plants
• Consumers

  Get energy from the sugars produced by the producers. A pond snail is a good example of a consumer because it eats plants.
• Decomposers

  Break down plant and animal material and return the nutrients to the soil. Bacteria and fungi are good examples of decomposers.
• Food chain

  Shows the direct links (hence the term 'chain') between producers and consumers in the form of a simple line (diagram C).
• Food web

  Shows all the connections between producers and consumers in a rather more complex (hence the term 'web' rather than 'chain') (diagram D).
• Nutrient cycling

  nutrients are foods that are used for plants and animals to grow. When plants or animals die, the decomposers help to recycle the nutrients making them available once again for growth.
• Causes for change in the ecosystem

  • global scale changes such as climate change
  • local scale changes such as changes to a habitat e.g. when a hedge is removed
• Natural changes

  Ecosystems can adapt to slow natural changes. But if there is an extreme weather events like a drought it could have a big effect
• human-driven changes

  Humans have many effects on the ecosystem for example agriculture and farming (using fertilisers), removing hedges, deforestation
• Tropical rainforest - The region of the world with the highest rainfall and the greatest diversity of plants and animals.
• Desert - High temperature during the day and low temperature during the night and low rainfall
• polar biome - very low temperatures and dry conditions
• Forests (Deciduous and Coniferous) - Deciduous trees lose their leaves during winter to retain moisture and coniferous trees are cone shaped and evergreen to maximise photosynthesis.
• Temperate grass land - grassland with a moderate climate, with dry summers and mild winters
• Mediterranean - hot, sunny, and dry summers with mild winters.
• Savanna - low altitudes with wet and dry seasons. The dry season is very hot with wild fires and the wet season has violent thunder storms
• Tundra - A region of cold, dry land, typically with permafrost. Very fragile ecosystem