Decomposers

 

Introduction:

Decomposers are vital components of the nutrient cycle.  Without decomposers, nutrients would not cycle back into our environment and waste would accumulate at an alarming rate.  If decomposers did not exist, within a month the earth would be covered in a layer of dead flies almost twenty feet deep!  Thankfully, decomposers consume dead plant and animal matter, so the nutrients contained within them can be reused.  Think of pop can recycling.  When pop cans are recycled, they are melted down into aluminum and sent off to processing plants so the metal can be used again.  If we did not recycle pop cans, we would run out of aluminum in the future.  Likewise, if nutrients were not recycled in our environment they would not be available to other organisms.

 

Task:

In this activity, you will be assigned to a group with two other people.  Your task is to gain a better understanding of the three main types of decomposers:  Fungi, Bacteria, and Insects.  Each member in the group will research a type of decomposer and report his/her findings to the other members.  In addition, there will be an extra activity for those of you who are interested in decomposers and environmental science.

 

Process:

Below are listed the three main types of decomposers and some interesting facts.  Each group member will be responsible for researching some important information about a certain decomposer.  The oldest member of the group will research bacteria as decomposers.  The youngest member will be responsible for researching insects and their role as decomposers.  The other group member will focus his/her research on fungi’s role in decomposing.  In addition, there is a research guide for each member to submit.  

Click Worksheet to get Decomposer Activity One.  (Print out this worksheet and use it as your research guide.)

The guide helps to focus in on some important aspects of these decomposers.  However, each member is free to broaden his/her study to include more facts.  You must complete the research guide, but feel free to continue researching.  Below each of the following decomposer categories, you will find some links to interesting sites that will help you with your research.

 

 

Bacteria

From the kingdom Monera, bacteria are the simplest organisms on the planet.  Bacteria are unicellular animals and are prokaryotic.  In just one spoonful of rich, dark soil, there are more bacterial organisms than there are human beings on the planet earth.

Bacteria Links:

Bacteria A-Z Science

NatureWorks

What is a Decomposer?

 

 

Fungi

From the kingdom Fungi, fungi can be unicellular or multicellular.  Fungi are eukaryotic organisms.  The largest organism on the planet earth is a fungus.  How can this be?

Fungi Links:

Kingdom: Fungi

NatureWorks

What is a Decomposer?

 

 

Insects

From the kingdom Insecta, insects are multicellular organisms and their cells are eukaryotic.  The Dung Beetle collects animal droppings and forms them into a ball.  The Dung Beetle then places the ball in an underground nest for its growing young to consume.

Insect Links:

Worms as Recyclers

NatureWorks

What is a Decomposer?

 

 

Evaluation:

For this activity, you will be grading your research assistants and yourself.  Each group member will determine an appropriate grade for the other two members’ papers based on the following criteria:

5 - The researcher answered all of the research questions with complete sentences and provided at least two interesting facts about his/her class of decomposers.

4 - The researcher answered all of the research questions with complete sentences and provided at least one interesting fact about his/her class of decomposers.

3 - The researcher answered most of the research questions, or answered all but did not use complete sentences. 

2 - The researcher did not answer all of the questions and did not use complete sentences.

1 - The researcher answered only a few questions, his/her work is hard to read and shows poor time management.

0 - The researcher did not answer the questions, or only answered one.

 

After each member gives each paper a score, the researchers will also evaluate their own papers, add the total scores together, then divide by the total number of scores received.

 

Example:

Researcher #2 receives scores of 4 and 5 from the other researchers.

Researcher #2 then gives him/herself a score of 3.

Add all the scores received:   4 + 5 + 3 = 12

Then divide the sum by 3 (which is the total number of scores received):  12 / 3 = 4

Therefore, researcher #2 receives a score of 4 for the paper.

In addition to this grade, the instructor may also evaluate your performance, so be thorough!  Complete your tasks as efficiently as possible to ensure you finish on time.

 

Conclusion:

This activity was meant to provide an overview of the importance of decomposers in the nutrient cycle, as well as give the researchers a better idea of the different types of decomposers and their lifecycles.  Decomposers may be an essential part of the nutrient cycle, but they are only a small part of the web of life.  Think about how other organisms interact with their environment and the role they may play in this cycle.  Ecosystems can be considered the most complex and amazing bionetworks on earth, and human beings may never fully understand all of the relationships within them.  This is only the beginning.  In real life, a group of researchers, like yourselves, would be assigned similar tasks.  It is up to the researchers to report their findings to each other, and the public.  In addition, this activity gives group members an opportunity to rate their performance and the performance of other researchers.  You may find that if one researcher does not do his/her job, the research will suffer and the task will not be completed.

If you would like to rate this activity, send an email to the address listed below.  Just as you rated each of your group members, it is important that the designers of this activity be rated.  If you have any suggestions or comments you would like to share, please let us know.

Email Decomposer Feedback Comments to: brandtdk06@mail.uww.edu

 

Further Explorations:

In class, you created miniature compost heaps to recycle nutrients.  Think about where and how you would make a larger one to recycle household wastes.  This could be done by yourself, with a friend, with a relative, or with your parents.  Compose a list of guidelines and procedures for establishing a compost heap and present it to your instructor.  These compost heaps not only keep waste from accumulating in the landfills, they also provide a good source of organic material for gardens, houseplants, and flower beds.  Talk with your parents and relatives about actually setting one up.  It is your job to convince them that it is a good idea.

Click HERE for a great website to get you started!

 

Cool Web Sites:

www.cellsalive.com

www.cytographics.com

www.discovery.com

www.popsci.com

 

 

Decomposer Group Members:

Dani Brandt, Justin Frey, Kevin Hermanson, Charles Kealy, Tim Ketter, Jeff Liddicoat