In this lesson you will use a computer simulation to construct your own food webs. The basic goal is to construct a food web that will lead to stable populations that will survive for at least 100 generations.
Lesson One: Introduction to the Simulation.
Go to the Gingerbooth web site and find the Ecology Lab simulation. You will have to scroll down the page a bit to find this program. Click on the screen shot of the program to start. Most of the controls are self explanitory. There are four levels in this ecosystem: plants (producers), herbivores (primary consumers), omnivores, and top predators. You can click on each of these to add them to the ecosystem and determine what the consumers are eating. Once you have set up the food web, click on the Run command and you will see the populations of the species over the course of 100 generations.
Some important points to keep in mind:
- Always hit the Reset button when starting the next Run.
- Put the cursor on the population graphs and you will see the number of individuals for each species.
- If the number is zero, then you need to try again. Your goal is to have all species above 0 population size at generation 100.
- Rember that the omnivores and top predator have many different options for food; you can select more than one at a time.
Try setting up an ecosystem with 2 plants, 2 herbivores, and one omnivore. Run the simulation a few times to get used to the controls.
Lesson Two: Simple Food Web.
Use the instructions from lesson and construct a stable food web with all three plants, 2 herbivores, and 2 omnivores.
Once you have a stable food web, note the connections among the various species. Better yet do a screen capture and print this out. These diagrams will be the results section of you lab report.
Lesson Three: Intermediate Food Web.
Do the same type of simulation as in Lesson Two. This time use 3 plants, 3 herbivores, and 2 omnivores.
Lesson Four: Complex Food Web.
Construct a stable food web using all 9 species available in the program.
Answer the following questions as part of your lab report conclusion.
- Which of the three food webs was most difficult to design? Suggest a reason why this might be the case.
- Was it easier to construct the last food web when the top predator ate both omnivores and herbivores rather than just omnivores? Explain why this might be the case.
- For the last food web you constructed, diagram this ecosystem as an Energy Pyramid.