Ecology

• abiotic factors- non living factors that affect the environment and living organisms
• biotic factors- living things that can affect an organism, such as predators, parasites, and pathogens
• ecosystem- the interaction of all the organisms in a particular area and the non-living parts of the environment
• community- the populations of different species living in a habitat
• population- the whole group of organisms of the same species that live in the same area at the same time
• organisms need things from the environment and from other organisms in order to survive and reproduce
• plants need light, space, water and mineral ions from the soil
• animals need space, food, water and mates
• interdependence- each species depend on other species for survival
• abiotic factors include:

  • moisture level
  • light intensity
  • temperature
  • carbon dioxide levels
  • wind intensity and direction
  • oxygen level
  • soil pH and mineral content
• biotic factors include:

  • new predators
  • competition
  • new pathogens
  • availability of food
• structural adaptations: features of an organism's body structure- like shape or colour
• behavioural adaptations- ways that organisms behave- e.g. some birds migrate to warmer climates in winter
• functional adaptations: things that go on inside an organism's body- like reproduction and metabolism

  ->desert animals conserve water by producing very little sweat

  ->brown bears hibernate to lower metabolism
• some microorganisms such as bacteria are known as extremophiles - they are adapted to live in extreme conditions
• environmental changes can cause the distribution of organisms to change e.g. availability of water, temperature, atmospheric gases
• decomposition can produce compost
• the rate of decay can be affected by:

  • temperature
  • oxygen availability
  • water availability
  • number of decay organisms
• biogas is made by anaerobic decay of waste material
• biogas is made in a simple fermenter called a digester or generator
• two main types of biogas generators:

  batch generators

  continuous generators
• biogas batch generators- make biogas in small batches, manually loaded up with waste
• biogas continuous generators make biogas all the time, waste is continuously fed in, and biogas fed in at a steady rate