The Tullgren Funnel

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Introduction

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

To extract small animals from a sample of leaf litter.

Method

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.

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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©  Shirley Burchill 2009