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The
Tullgren Funnel
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Introduction
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The Tullgren Funnel is
an apparatus which helps to remove living organisms from leaf
litter. Leaf litter is placed in a filter funnel which is
covered with black paper. The funnel is then held over a
bottle containing a mixture of alcohol and water. There is a
piece of gauze present to prevent soil entering the liquid.
Once the leaf litter has been placed in the funnel, the
apparatus is put under a strong light for at least two weeks.
The soil dries out slowly and this encourages the living
organisms to move downwards.
Aim
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To extract small
animals from a sample of leaf litter.
Method
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1. Set up the apparatus as shown in the diagram
below.
2. Leave the apparatus in a
light cupboard for at least two weeks.
3. After two weeks, pour the
alcohol and water mixture into a dish and observe the mixture
under a binocular microscope.
4. Identify any organisms you
find.
5. Record the numbers of each
of the different organisms which were present in the leaf
litter.
Results
Example: How to
use the table
Every time
you find a spider mite extract it from the liquid and place an
X in the table. When all of the organisms have been extracted,
count the total for each. Extra lines have been left at the
end of the table for any unlisted organisms you might find.
| Example |
Occurrence |
Total |
| spider mite |
X |
X |
X |
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Organism |
Occurrence |
Total |
| spider mite |
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| insect larva |
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| insect |
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| centipede |
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| millipede |
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| water bear |
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| pseudo
scorpion |
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| springtail |
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| worm |
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Conclusion
Write a
conclusion to this experiment.
How many different organisms did you find?
Which of the organisms are decomposers?
Which of the organisms are carnivores which feed on the
decomposer organisms?
Was the forest leaf litter wet or dry when you collected it?
How might this effect the number of organisms present?
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