LAB ACTIVITY to reinforce effects of INVASIVE SPECIES on ecosystems + important vocabulary……..
Producer  Native Herbivore ---> Predator
\ Invasive Herbivore
RULES for every generation of this game:
# of producers doubles
each Native Herbivore eats 1 plant to survive
Every 2 Native Herbivores that survive have 1 offspring
Each Predator eats 2 Native Herbivores (predators can survive many generations)
Invasive Herbivores eat plants before Native Herbivores. Invasive Herbivores eat 1 plant each time.
2 Invasive Herbivores produce 2 new offspring if they each eat 1 plant
Invasive Herbivores have NO natural predators
Each person is in charge of 1 population. Decide who will be a:
Producer (label/sketch a leaf on 16 cards)
Invasive Herbivore (label/sketch on 8 cards)
Native Herbivore (label/sketch on 16 cards)
Predator (label/sketch on 2 cards)
ROUND 1/ 1st Simulation:
YEAR 1: Producer lays out 8 producer cards
What happens? _________________________________
YEAR 2: Producers double in number & Native Herbivore lays out 8 cards
How many producers get eaten this round? _______________________________
How many new offspring will Native Herbivores produce? ___________________
Predator lays out 2 cards
How many Native Herbivores get eaten? _________________________________
How many Invasive Herbivores get eaten? ________________________________
ROUND 1 of the simulation is over
Complete this table
Population Size @ Beginning & End of One Generation
start
finish
Producers
Native Herbivores (NH)
Predators
Repeat and record the number of Producers, Native Herbivores & Predators you begin with & how many
remain after play. Compare #’s w/other groups
SIMULATION 2 - Repeat using invasive herbivores (they have been brought to the area by humans)
Yr #1 – Producer lays out 8 cards
Yr #2 – Producer population doubles
1. How many are in the population now? ________________________
2. TWO Invasive Herbivores eat (rules say they will eat before Native Herbivores do)
a) How many producers will they eat? _____________________
b) How many offspring will Invasive Herbivores give birth to? _________________________
3. EIGHT Native Herbivores may now eat after the Invasive Herbivores
a) NEXT – The TWO Predators eat prey. How many Native Herbivores remain? ____________
b) How many Invasive Herbivores remain? _____________________________
Play another round by starting with Producers. Double the Producer population that remains
4.
5.
6.
7.
Invasive Herbivores eat. How many producers are eaten? _____________________________
How many new Invasive Herbivore offspring are produced? ____________________________
How large is the total population of Invasive Herbivores now? __________________________
Native Herbivores eat. How many produces are eaten? _______________________________
Now the Predators hunt.
8. Can you complete another round? ___________________
9. What happened to the population of producers?
10. What do you predict will happen to the predator population? Why?
11. Why was the invasive herbivore population allowed to grow out of control?
12. What is your prediction for the human population on Earth? Do you think it will reach carrying capacity &
level off, or do you think it will crash? Choose one of these and describe how and why you think changes
will occur.
13. Do you think there is any relation between the exponential growth of the human population & the
extinction rate of other living things? Explain.