1. Catalyst: August 27th, 2013
If you did not finish your pyramid, grab some scissors/glue and a class copy. If I took up your energy pyramid, I will hand it back after the bell rings.
After you finish your pyramid: Begin working immediately on your Energy Flow quiz.
You MAY NOT write on the quiz.
You MAY NOT use notes (i.e. HAVE YOUR DESK CLEARED)
Expectations: Silent. By yourself. In your seat.

2. Agenda Catalyst: 10 minutes Carrying Capacity PowerPoint (20 minutes)
Carrying Capacity Graphic Organizer (10 minutes)
Exit Ticket (Remaining )
Homework: Carrying Capacity Quiz on Thursday

3. Announcements
Office hours today
Carrying Capacity Quiz on Thursday

4. Objectives
SWBAT name three major factors that determine population growth.
SWBAT define immigration and emigration.
SWBAT describe exponential growth and identify an exponential growth curve.
SWBAT define carrying capacity and identify the (limiting) factors that contribute to the carrying capacity for a population
SWBAT predict changes in population size based on limiting factors and carrying capacity in an ecosystem
SWBAT interpret a growth curve for a population

5. Vocab Review Abiotic Biotic
Producer, Primary Consumer, Secondary Consumer, Tertiary Consumer
Population
Species

6. How Many?
We have learned about populations of organisms increasing or decreasing in size based on changing biotic and abiotic factors
Biotic?
Abiotic?
But what controls how many organisms exist in a population in the first place?

7. Human Population Maps
/world-population-data-sheet/world- map.aspx#/map/population

8. Key Point 1
Three main factors determine whether a population increases or decreases: number of births, number of deaths, or number of individuals that move into or out of an area.
Immigration is the movement of individuals into an area (Into = Immigration)
Emigration is the movement of individuals out of an area (Exit = Emigration)

9. Key Point 2
Under ideal conditions, with unlimited resources and space, a population will experience exponential growth.
Actual populations stabilize rather than growing endlessly.

10. What determines population?
Why can’t we have1,000,000 students here at Overton?
Space
Teachers
Supplies
Student Behavior
These resources are our limiting factors
Limiting factors limit the number of organisms that can live somewhere

11. Limitations on Populations
There can never be an unlimited number of organisms in a population in an ecosystem.
Why?

12. Key Point 3: Carrying Capacity
An ecosystem can only support as many organisms as it has resources and space for
Carrying capacity = maximum number of organisms that can live in one population in an ecosystem over time
Every species has a different carrying capacity.
Food and water, space, and predators
are the limiting factors that determine
carrying capacity for a population

13. Imagine Your Fridge
Your fridge is like all of the resources (food, water, free space) in an ecosystem.
What if we want to throw a party?
There’s only so much food in there, and it will only last so long until you re-fill it.
Of course, we can’t just re-fill it all the time. Some of us have to wait until that next paycheck before we can buy groceries.

14. Imagine Your Fridge
We can keep inviting people, as long as there’s enough food in the fridge.
Each friend eats a different amount of food, just like each species has a different carrying capacity
But with each new guest, there’s less to go around.

15. Imagine Your Fridge
The fridge won’t replenish magically, and I don’t have the money to keep putting food in the fridge forever.
So too many guests means that…
So too many animals means that…
Someone goes hungry…
Not enough food/water/free space…
And leaves the party. 
And organisms die. 

16. Key Point 4:
There are two types of limiting factors: density-dependent limiting factors and density- independent limiting factors.

17. Key Point 4 Continued
Density-dependent limiting factors have more of an effect on large or crowded populations.
Examples: Competition, Predation, Space
Density-independent limiting factors can affect both large and small populations.
Example: Earthquake, Volcanic eruption

18. Key Point 5: Carrying Capacity
A population growth curve can be used to predict changes in population size and to identify carrying capacity
A = x-axis = time
C = y-axis = population size
B = graph shows population size at any given time
D = carrying capacity

19. Carrying Capacity
Remember from math class, exponential increase = constantly doubling. (Makes a curved line on a graph.)
Analogy: each person at the party invites a new friend. Each one of them invites another new friend. Etc.
When a population is below its carrying capacity (B), it increases in size
Plenty of food and space
Birth rate is higher than death rate

20. Carrying Capacity
Analogy: We run out of food at the party, and people start to leave.
Remember over the last few days, when one population in a food web died, so another population that ate it decreased in size? That’s because the carrying capacity decreased!
When a population is above its carrying capacity (A), it decreases in size
Not enough food and space; or too many predators
Death rate is higher than birth rate

21. Carrying Capacity
Analogy: Once there’s enough food again, more people will come. But we’ll probably be a bit more cautious, and not invite people as quickly. So if we go over carrying capacity, it won’t be by as much.
This happens over and over… but the increases and decreases get smaller and smaller…

22. Carrying Capacity
Remember from yesterday: stable = does not change
This is the concept that my students last year had the most trouble with. Really harp on this.
Eventually, population size stabilizes at the carrying capacity (C)
Stabilizes= stays the same
Birth rate = death rate

23. On what date did the rabbits reach their carrying capacity?
CFU 1
On what date did the rabbits reach their carrying capacity?

24. Why does the rabbit population increase in the highlighted region?
CFU 2
Why does the rabbit population increase in the highlighted region?

25. CFU 3
A fire kills grass and other producers in the ecosystem. What will happen to the carrying capacity for rabbits?

26. determined by
such as
above it
below it
Honors: Independently; Regular: Together
WORD BANK: water, carrying capacity, pop. size increases, limiting factors, food, pop. size decreases, space

27. Summary
An environment can only support as many organisms as there is available food, water, and free space
Carrying capacity = maximum number of organisms that can live in an ecosystem based on these limiting factors
We can read a population growth curve to predict changes in population size
Below carrying capacity = increase in size
Above carrying capacity = decease in size
Over time, population stabilizes at carrying capacity

28. Exit Ticket
What are three limiting factors that determine the carrying capacity of a population in an ecosystem?
What is happening to the population at point A in the graph and why?
What is happening to the population at point B in the graph and why?
What is the carrying capacity for the population based on the graph shown?

29. Catalyst #9: August 28th, 2013
1. When did the rabbits reach carrying capacity? How do you know?
2. What is happening to the population during June?
3. What are some potential factors that could limit the rabbit population?

30. Agenda Catalyst: 5 minutes Oh Deer! Simulation: 20 minutes
Population Graphing: 20 minutes
Homework: Population Graphing (If not completed)
Study for Carrying Capacity Quiz

31. Announcements
Energy Flow quiz make-up

32. Objectives
SWBAT define carrying capacity and identify the (limiting) factors that contribute to the carrying capacity for a population
SWBAT predict changes in population size based on limiting factors and carrying capacity in an ecosystem
SWBAT interpret a growth curve for a population

33. Oh Deer! Simulation Number off: Ones = Deer; Twos = Habitat
Line up back to back
Deer choose what resource they are seeking: food, water, habitat (hand signals for each)
Habitats choose what resource they are: food, water, habitat (hand signals for each)
When I say go:
Turn around
Deer go to resource with same signal!
If two deer go to the same resource
Deer take resource back to their side; Deer without resources “die” and join the habitat side; Habitats taken to the deer side become deer because of successful “reproduction”

34. Calculating Population Changes

35. Population Growth Practice

36. Population Growth Practice
Discuss the results of your graph. What trends do you see? (How does the graph change?)
Did this population reach carrying capacity? Why or why not? If so, indicate WHEN the population reaches carrying capacity and indicate the maximum number of individuals that can be supported.
What factors are responsible for the rabbit growth trend?  
If predators like foxes and cats, which often prey on rabbits, were introduced into this environment during the 10th generation, what would happen to the population growth? Explain your answer below:

37. Honors: Independent Practice
Complete Population Growth Data Set 2 independently

38. Regular: Independent Practice
Complete Population Growth Data Set 2 independently OR with a partner

39. Reminders Carrying Capacity quiz tomorrow
If you do not complete the IP….