Design a compost system or small garden plan that applies matter-cycle and ecosystem-role concepts to a real, practical goal.
Now you get to be the ecosystem engineer. A compost system deliberately speeds up the natural matter cycle: you gather food scraps and yard waste, matter that would otherwise be thrown away, give decomposers what they need, moisture, air, a mix of materials, and let them turn waste into nutrient-rich soil.
Alternatively, you can design a small garden plan that thinks like an ecosystem: which producers to plant, what consumers, like pollinating insects, they might attract, and how compost or natural decomposition could feed the soil. Either design should show that you understand how matter and roles, producer, consumer, decomposer, fit together on purpose, not just by accident.
Mastery looks like: They can design a compost or garden plan with specific, justified choices that reflect matter-cycle and ecosystem-role understanding.
Common stumbles: Designing a vague plan without specific materials or reasoning; forgetting that decomposers need air and moisture, not just scraps piled up.