Ecosystems Curriculum

This section addresses students' tendency to consider only the most obvious causes of an effect. It helps students to see that non-obvious microbes are the primary decomposers, that things don't "fall apart" on their own, and that detritivores that we can see, such as earthworms and sow bugs, are responsible for only a small percentage of decomposition.

Section 3: Understanding Goals

Subject Matter

• "Decomposers" are organisms that cause things to decay by eating (or digesting) organic matter.
• Some decomposers, such as earthworms, are more obvious than others, such as microbes.
• Some decomposers are microbes—tiny organisms that are typically too small to see with just your eyes.
• Microbes do most of the work of decomposition

Causality

• There are obvious and non-obvious causes for decay.
• There are cycles of decay happening all of the time (simultaneously). Thus there will always be nutrients being made available in the ecosystem.