Decomposition Investigation

How do plant parts decompose and how does decomposition support plant growth? Make observations of plant matter at different stages of decomposition and make inferences about cycles of matter in ecosystems.

Materials 

• Decomposing fruits (if possible, use fruits at different stages of decomposition) 

• Magnifying glass (optional) 

• Three to four feet of precut string (optional) 

• Access to a garden (or similar space) (optional) 

Observation Ideas 

• Spend a minute observing the decomposing fruit. What signs of decomposition do you notice? Are there any insects, animals, or signs of life present (e.g., animal bites)? What stage of decomposition is the fruit in? 

• Use your lens to examine the fruit up close. What do you see now that you did not see before? 

• Find multiple fruits at different stages of decomposition and compare them.  

Discussion Ideas  

• Since fruit is made of organic (living) matter, it will break down or decompose at a fairly fast rate. An orange peel takes approximately two months to decompose. Examine fruit at different stages of decomposition. Line up the fruit in order of decomposition or draw a sketch of the different stages of decomposition. Estimate how long each fruit has been decomposing.  

• If outside, use one of the precut strings to create a circle on the ground. Spend a minute or so observing the soil you see in the circle. Do you see anything that might be decomposing? This can be discussed as a group or written/drawn. 

• How might the decomposition of fruit help with plant growth? What predictions do you have and how might you find out if your predictions are correct?