Life Cycle - Natural Environment (2B)
Post Lab 

  • Investigating the nutrient cycle of a forest. 
  • Comparing the components of the nutrient cycle. 


  • decomposers
  • nutrient
  • organic matter
  • worksheet
  • crayons

Students use a worksheet to trace a nutrient cycle.   


Soil is composed of organic matter and broken down rocks.  The organic matter is from other surrounding life that has started to mix with the small rocks.  Many soil dwelling organisms spend their lives breaking down dead animals and plants, releasing nutrients for use by growing plants.  These decomposers, sometimes called reducers, are responsible for the fertility of the soil.  

Erosion caused by water, wind, and heat can break the rocks down.  Even living things such as lichens and plant roots contribute to the breaking down of rocks.  Rocks are made of minerals, and minerals have many helpful elements in them that can be chemically released.   This process, together with the decomposition of organic matter, eventually leads to the creation of new soil.  However, this can take a very long time, one inch of topsoil may take five hundred years to form.    .  


  1. The worksheet tries to put all the information together, so students can see how it is all related.  See if the students can figure out what is going on and have them state what they think is going on in the picture. 
  2. (1) Dead leaves and other plant and animal matter. 
    (2) Decomposers break down organic matter. 
    (3) Rocks broken down.  
    (4) Minerals and other nutrients released into soil. 
    (5) Plant grows.  
    (6) Water and air penetrate soil. 
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