Discovering Decomposers!

Submitted by: Serina Bain
Grade level: ECE, elementary
Core Competencies: creative-thinking, critical thinking, positive-personal-and-cultural-identity
Subject Disciplines: science-education,indigenous-education

Location: any natural place (e.g. playground, forest, beach)

Grade

1-4 could be extended to grade 7

Materials:

• Hard writing surface (clip board, cardboard with clip)
• Pencil
• Coloured pencils (optional, helps with drawings and observations)
• Magnifying glasses (optional, kids love to use them)
• Ruler (optional, helps with observations)
• Small plastic container, white or clear (optional)
• Phone with camera

 

Handouts and Additional Resources:

Scavenger Hunt:  See Appendix A below

Video: The Dirt on Decomposers: Crash Course Kids- https://www.youtube.com/watch?v=uB61rfeeAsM

HCTF-Education- Wood bugs – https://www.hctfeducation.ca/wp-content/uploads/2016/08/Wood-Bug-Article.pdf

Science World– Decomposers-  https://www.scienceworld.ca/resource/introducing-decomposers/

 

 Background:

Decomposers play a critical role in the flow of energy through an ecosystem. They break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers.

Decomposers feed on dead things: dead plant materials such as leaf litter and wood, animal carcasses, and feces. They perform a valuable service as Earth’s cleanup crew. Without decomposers, dead leaves, dead insects, and dead animals would pile up everywhere. Imagine what the world would look like!

More importantly, decomposers make vital nutrients available to an ecosystem’s primary producers—usually plants and algae. Decomposers break apart complex organic materials into more elementary substances: water and carbon dioxide, plus simple compounds containing nitrogen, phosphorus, and calcium. All of these components are substances that plants need to grow.

* Adapted from: https://www.nationalgeographic.org/encyclopedia/decomposers/

Common Decomposers found in the forest

Fungi

   

Fungi release chemicals externally to break down dead plants or animals into simpler substances. They absorb some of these substances for growth, but others are utilized by other organisms, including plants.

Bacteria

Bacteria are tiny, microscopic organisms. The ones that live on dead materials help break them down into nutrients which are returned to the soil.

Invertebrates

Earthworms digest rotting plants, animal matter, fungi, and bacteria as they swallow soil. The waste that comes out of their bodies at the other end contains important minerals and nutrients ready for plants to absorb.

Millipedes, sow bugs, and fly larvae (maggots) do a similar process, at different rates, but they rely on a different food source.

Centipedes are part of the decomposer group because they eat other invertebrate decomposers, thereby keeping the decomposer populations balanced.

Wood bugs Not a bug – a crustacean Related to shrimp and lobsters – where do those live? Wood bugs breathe through simple lungs that need to be very moist, therefore need moisture in the air Keep them under leaves provided. You can handle them gently, but not for long or they will run out of air.

 Activities:

1. Go to your designated outdoor area.
2. Start off by asking if anyone knows what a decomposer is? Can they think of any examples?
3. Share instructions before handing out materials:

• Have students pair up
• Each pair will receive materials listed above
• Set out designated boundary for decomposer discovery
• You will be going on a decomposer discovery. Use the scavenger hunt paper to help guide you (appendix A).
• Students must try to find the three decomposer on the sheet by rolling over decomposing logs, rocks, leaves in a forested area– and make close observations. Prep students on what are appropriate observations for their age.
• There are three blank spots on the scavenger hunt. Have students record any other ‘creatures’ they find that the think would fit into the decomposer category and record observations.
• Finish the three questions at the bottom of the scavenger hunt with their partner.
• Come back to group and share their discoveries

4. Back in class give time to finish up scavenger hunt paper. Students will hand this in r put in their portfolios
5. Watch the: The Dirt on Decomposers: Crash Course Kids https://www.youtube.com/watch?v=uB61rfeeAsM
6. Look at extensions to dive deeper into decomposers.

Assessment:

• Students will hand in scavenger hunt and submit to science portfolio
• Video record students’ findings during scavenger hunt-add to portfolio
• Student is enthusiastic and engage during activity
• Student shares their findings
• Student can identify and locate local decomposers
• Student can describe the importance of decomposers to the forest eco-system

Extensions:

Dive deeper and get to know a decomposer.  This could be as a class, small group, pairs or individual.

Safety Considerations:

• ***Mushrooms*** – Look don’t touch or pick
• Prepare Students– ensure students are aware of this extra time spent outdoors. Go over appropriate clothing and behaviours while out on your decomposer mission.
• Prepare Parents – Ensure parents are aware of the extra time spent outdoors and recommend appropriate clothing for the season. If you are going off school grounds make sure all required permission forms have been filled out.
• Prepare Yourself
• Do a reconnaissance trip so you know your way to and from your location and time needed to travel to and from.
• Check the weather, high winds in the forest are reason to switch to a plan “B”
• Ensure you have appropriate clothing and footwear for the day.
• Have a plan “B”
• Bring a sound signalling device (whistle, harmonica, bells etc.)
• Grab and go first aid kit, and any medications specific to students in you class/group
• Communication device (cell phone) with pre-programmed school administration numbers
• Gather required materials for the activity
• Ensure the front office or your admin know of your outdoor location and the time range you will be out

Sustainability Considerations:

Please remember to return all decomposers and any moved forest items back to their original location.

 

Appendix A: Decomposer Discovery: Scavenger Hunt!

Wood Bug                 Observations:	Slug                 Observations:	Fungi                 Observations:
What else did you find?                   Observation:	What else did you find?                   Observation:	What else did you find?                   Observation:

 

What do these decomposers have in common?

 

 

Where do decomposers live?

 

 

What do decomposers need to survive?

 

 

What common organisms are in this group?