Key area 2 - Distribution

• The 6 biotic factors

  Food availability

  Grazing

  Disease

  Predation

  Competition of resources
• The 4 abiotic factors

  Moisture levels

  Light Intensity

  Ph

  Temperature
• measuring Light intensity

  •You measure it with a Light meter

  •One possible source of error is measuring it in your own shadow and you minimise this by not measuring it in your shadow
• Measuring soil moisture

  You measure it with a Moisture meter

  one possible source of error is not cleaning probe between sites and to minimise this you clean the probe between sites
• Measuring Tempreture

  You measure it with a thermometer

  one possible source of error is not putting thermometer at the same depth and to minimise this is to put thermometer at same depth each time
• Measuring Soil Ph

  you measure this with a Ph probe

  one possible source of error is not cleaning probe between sites and to minimise this is to clean probe between sites
• What could be sampled using a quadrat

  A population
• 2 possible errors of using a Quadrat and how to minimise it

  Not throwing quadrat randomly - throw randomly.

  not repeating results - repeat results
• What can be used to measured using a pitfall trap 


  Small insects moving across the surface
• Why do each sampling technique require adequate replication

  To increase reliability
• When can you use a paired statement key

  To identify organisms
• An abiotic and biotic factors that can have an increase or decrease in biodiversity

  Predation

  miosture levels
• Define an indicator species

  By their presence or absence they can indicate the quality of the enviroment
• Example of and indicator species

  Lichens indicate levels of pollution