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Interactive Labs

Ecology Lab

Lessons > Food Web > Step 1

First you'll run a less than "real-life" scenario. Choose only one organism from each trophic level and make sure that the food chain goes in a straight line from one trophic level to the next, i.e., Herbivore A eats Plant A, Omnivore A eats Herbivore A, and the Top Predator eats Omnivore A. Let Plant B survive on its own and see what happens. Predict whether each species will survive, and whether it will increase or decrease in number, as well as whether Plant B will survive to the end. Record your prediction in the Data Table and then run the simulation twice and record your data. Use X for "die out," ↑ for "increase in numbers," and ↓ for "decrease in numbers." Answer the following:

  1. Was your prediction correct? How did you arrive at your prediction? What differences were there between your prediction and the simulation?
  2. What would happen to this imaginary ecosystem if the producers were to die out?
  3. Did any of the species increase in number? What could account for this increase? Which species decreased in number and what might account for this decrease?
  4. Which populations would benefit the most from the presence of decomposers?

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