EXPERIMENTAL INVESTIGATION 9.3 How can we examine the non-living factors in a local habitat?
Equipment
Soil thermometer Trowel
Method Soil temperature
1. Place a soil thermometer in the ground to a depth of 10 cm.
2. Leave for 24 hours and then record the temperature.
Soil pH
1. Using a trowel, dig up a small sample of soil from the top 10 cm.
2. Place the soil in a beaker and add distilled water.
3. Mix using a spatula. 4. Allow to settle for 30 minutes.
5. Record pH using a digital pH meter (or universal indicator paper).
6. Repeat for different locations in the habitat. Light intensity
1. Take the cover off the light meter and place it on the ground.
2. Stand away from the light meter to avoid casting a shadow.
j Go to page 20 of your Experimental Investigations Log to write up this investigation. : Fig. 9.14 To investigate soil pH
3. Record the light intensity reading. 4. Repeat for different locations in the habitat.
Step 5: Observe interactions in the habitat
The data collected during a habitat survey provides examples of: • adaptations • competition • feeding relationships • interdependence • variation within and between species
) Fig. 9.15 A spider eating a bee on a flower
Elements of Science 87 Beaker Distilled water Spatula Digital pH meter Light meter