Predict what would happen to the community of aquatic macroinvertebrates in a small forested stream if a family of beavers, well known ecosystem engineers, moved into the area.

What does this experimental investigation lack

Analyze how the four requirements for life were identified by scientists

How do energy and matter move through an ecosystem? both energy and matter unidirectionally flow through an ecosystem. both energy and matter cycle within an ecosystem. matter unidirectionally flows through an ecosystem, whereas energy cycles within an ecosystem. energy unidirectionally flows through an ecosystem, whereas matter generally cycles within an ecosystem.