Subject Matter

• An ecosystem is a combination of living things in a community and the non-living things in the physical environment surrounding them (biotic and abiotic factors).
• Different organisms in ecosystems need certain things to survive, such as water, air, soil, food and sun.
• Organisms in an ecosystem can be put into three categories: producers, consumers and decomposers.
• There is interconnectedness in an ecosystem, and changes in one population in an ecosystem may cause changes in other populations in that ecosystem.
• Energy from the sun is transferred in a domino-like pattern.

Causality

• Causes can have direct and indirect effects.
• Causes can have far-reaching effects.
• A seemingly small precipitating cause can have extensive effects.
• In a system, isolated effects are uncommon.
• Effects often appear to propagate in domino-like patterns including ones that branch or radiate out.