Students are to define what they believe constitutes an ecosystem. Students could work in small groups and share definitions to create a class definition. An ecosystem is a complex and self-sustaining natural system containing interactions between the biotic and abiotic world. An ecosystem contains many different kinds of organisms, which interact with each other and their physical environment. Share lists and create a class table for a number of ecosystems.
Students explain how the biotic and abiotic components of ecosystems interact or rely on each other.
Students decide which of the ecosystems in the table would contain the most organisms and to explain the reasoning for their choice. Discuss what would happen to an ecosystem if a particular component was missing or removed.