THE DELICATE BALANCE OF ECOSYSTEMS

1. THE DELICATE BALANCE OF ECOSYSTEMS Lab 9

2. 1.-Ecosystems are communities of organisms interacting with a particular environment. Invasive species can throw off the delicate balance of an ecosystem, destroying several species in the process. We are going to simulate the give-and-take of an imaginary ecosystem and observe what happens when the “delicate balance” of this ecosystem is corrupted.

3. 2- A very simplified food chain is diagrammed below, which will serve as the basis for our simulation. predator→ native herbivoreproducerinvasive herbivore eats eats

4. General rules for this simulation: I.- Every generation, the number of producer doubles. Assume that the plant population has enough sunlight, carbon dioxide, and water to produce new organisms. II.- Every generation, each native herbivore eats one plant to survive. Two native herbivores produce one new offspring each generation if they both consume one plant.

5. (cont) III.- Every generation, each predator must consume two native herbivores in order to survive into the next generation. The predators are capable of surviving for many generations.

6. (cont) IV.- Once an invasive herbivore enters the ecosystem, it is able to consume plants before the native herbivores can. The invaders each eat one plant every generation. Two invasive herbivores producer two new offspring each generation if they each have consumed one plant. V.- The invasive herbivores have no natural predators.

7. Procedure: • Have someone from your group cut out the playing pieces in your lab book. You need only one set of pieces (from one student’s lab). Lay all of the cut out pieces out on your lab table.