Model Ecosystems
Procedure: Read the information on the left panel of the Virtual Lab to
understand the components of the lab. Then, follow the procedure to assist you in
completing the chart and questions below.
Energy Conversion Efficiency for Ecosystem Trophic Levels
Journal:
1. Suggest reasons why the information represented in the pyramid of numbers of animals
of one of the ecosystems you studied may not truly represent that ecosystem.
2. According to your data, what is the ratio of third-order consumers to producers? Explain
your answer.
Ecosystem Producers 1st Order
Heterotrophs
2nd Order
Heterotrophs
3rd Order
Heterotrophs
Deciduous Forest
Hot Desert
Grassland
Antarctic Ocean
Shore
Freshwater Lake
3. Compare and contrast two of the ecosystems that you studied. How is the energy
conversion efficiency similar or different?
4. Does the population size increase or decrease at higher trophic levels in the pyramid of
numbers of an ecosystem consisting of a tree, insects (that are herbivores) and birds
feeding on the insects? Explain your answer.
5. What might happen to an ecological pyramid of numbers in a forest ecosystem if most
of the deer were killed due to hunting by people and disease?
6. What would happen to an ecosystem if the decomposers disappeared?
7. Could there be a food chain without herbivores and carnivores?