Biotic/Abiotic Factors

Biotic/Abiotic Factors

1. Abiotic Factors

   • Definition
     • Non-living parts of an ecosystem which are important in determining the type of organisms found in habitats.
   • Examples of Abiotic Factors
     • Temperature
       • Use a thermometer to find this out.
     • pH soil
       • Use a pH meter to find this out.
     • Light Intensity
       • Use a light meter to find this out.
         • Instructions on how to use a light meter.
           • 1. Push the switch onto the light position.
           • 2. Place the light meter on the surface of the ground so that the light sensor is pointing towards the brightest light source.
           • 3. Make sure that you shadow isn't covering the light meter.
           • 4. Examine the meter readings while the meter is in this position. Use the bottom scale (A-H).
         • Precautions you must take when using a light meter.
           • Take recordings at the same time of the day.
           • Make sure that the light meter is not under a tree or in the shadow of a building.
           • Take more than one reading.
     • Moisture Levels
       • Use a moisture meter to find this out.
         • Instructions on how to use a moisture meter.
           • 1. Push the switch onto the moisture position.
           • 2. Carefully place the probe vertically into the soil so it is about 4cm deep.
           • 3. If you hit a stone, take out the probe and put it in a slightly different position.
           • 4. Examine the readings whilst the probe is in the soil. Use the top scale (1-8)
         • Precautions you must take when using a moisture meter.
           • Don't force the probe into the ground if it is really dry. Use a tent peg to create a hole if this happens.
           • Make sure that the probe is in the ground at the correct depth.
           • Keep the probe in the ground when reading the scale.
           • Take more than one reading.

2. Biotic Factors

   • Definition
     • Living parts of an organism which are important in determining the type of organisms found in habitats.
   • Examples of Biotic Factors
     • Quadrat
       • Marks off a small piece on the ground so that different plants in the sample can be identified and counted.
       • A quadrat can also measure abundance.
       • The quadrat must be dropped randomly.
     • Pitfall Trap
       • Instructions on how to use
         • 1. Dig a hole in the ground deep enough to hold an empty yoghurt carton.
         • 2. Place an empty carton into the hole, making sure that the top of the carton is level with the ground.
         • 3. Leave until the next day to look at it.
       • Small animals living on the ground surface can be sampled using a pitfall trap.