1. Population Growth

2. Agenda 1.CH 5-1 Population Growth 2.CH 5-2 Limits to Growth

3. Population A population has 4 characteristics –Geographic distribution –Density –Growth rate So how many students are in here? How about in two rooms? Population density –the number of individuals per unit area

4. Volunteers How can a population change?

5. Populations can change by: Immigration – moving into a population Emigration – moving out of a population Birthrate Deathrate

6. Population growth graph X axis = time Y axis = number of individuals Exponential Growth (J curve) –Ideal conditions with unlimited resources –Population grows exponentially Logistic growth (S curve) –Resources are less available –Population growth slows or stops

7. Number of Mice Time (hours) Carrying capacity

8. Population Growth can be represented bycharacterized by represented by which cause a Exponential growth Logistic growth Falling growth rate S-shaped curve Limits on growth No limits on growth J-shaped curve Constant growth rate Unlimited resources Concept Map

9. Limiting Factors ► Limiting factor  A situation that causes the growth of a population to decrease 1. Some limiting factors depend on the size of the population. 2. Other limiting factors affect all populations in similar ways.

10. Limiting factors 1. Density dependent factors  Affected by population  Food, space, competition, waste, so on 2. Density independent factors  Population does not affect it  Natural disasters, weather ► Both are limiting factors that affect the overall population

11. Wolf and Moose Populations on Isle Royale 60 50 40 30 20 10 0 195519601965197019751980198519901995 2000 1600 1200 800 400 0 2400 MooseWolves

12. Homework SA 5-1 #1-6 SA 5-2 #1-5 Read Ch 5-3