Woodland wonders: Coed Bryn Oer: Woodland wonders

Trees and Environment

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Air Filters


- Children collect and wash leaves to find that trees clean our air filtering out pollutants.


: Bottle of water, yoghurt pots, paint brushes, coffee filter papers and funnel.


  • Split the group into pairs

  • Give each pair a yogurt pot, and a small paintbrush

  • Fill the pots with water

  • Ask the children to collect leaves from the trees

  • Wash the tree leaves in the pot using the paintbrush

  • Put the funnel in the top of the water bottle and place filter paper in it

  • After 20+ leaves ask the pairs, one at a time, to pour their water into the filter

  • When it has drained through, give the pair their filter paper

  • Let it dry and look at what is left on the filter paper

Follow up:


Trees are very important in purifying and cleaning the air we breathe. The dirt they clean out of the air can be seen on the filter paper as a dirty mark.
Where does this dirt come from? How do humans pollute the air?
Carry out the other activities in this section.