Grade 7 · Interactions in the Environment · Interactions in the Environment
Trace Change Through an Ecosystem
An ecosystem is a network of interactions among organisms and the non-living environment. Energy flows through the network, while matter cycles and is reused.
Visual model
See how the ideas connect
For students
Notice, predict, explain
Choose one part of the model. Predict how it connects to another part, then use the lesson evidence to explain your thinking.
For teachers
Pause for science talk
Show the model before the explanation. Ask “What do you notice?” and “What might change?” Then revisit student ideas after the worked example.
The big idea
Ecosystem change spreads through connected relationships
Producers, consumers, decomposers, water, soil, climate, and nutrients interact. A change in one component can alter energy transfer, matter cycling, population limits, and succession across the system.
Work it through
Follow change after a forest fire
- Step 1 A fire changes abiotic conditions such as light, soil surface, temperature, and available nutrients.
- Step 2 Because soil remains, secondary succession begins as surviving organisms and new colonizers establish populations.
- Step 3 Changing producer populations alter food and habitat for consumers, while decomposers return matter to the soil.
- Step 4 Water, nutrients, space, climate, and species interactions limit how many organisms the recovering ecosystem can sustain.