1. Chapter 52: Population Ecology

2. Population Growth Patterns
Type of Growth?
Exponential growth
“J curve”
CH52#6

3. Population Growth Patterns
Some populations of organisms reach a plateau in their growth. This is called their carrying capacity.
These populations are said to be growing with logistical growth.
“S curve”
carrying
capacity
CH52#6

4. Carrying capacity – The number of organisms that can be supported by a particular ecosystem *within natural resource limits-without destroying it.
*Limiting Factors…
CH52#6

5. Logistical vs. Exponential Population Growth Patterns
What is the carrying capacity of the population on the right?
About how many days did it take for the population to reach carrying capacity?
Which of the following is probably NOT a reason the population reached and maintained a plateau?
a. limits in food supply
b. competition with other species
c. competition for space
d. a major storm

6. Logistical vs. Exponential Population Growth Patterns
What is the carrying capacity of the population on the right? around 135 individuals
About how many days did it take for the population to reach carrying capacity? about 80 days
Which of the following is probably NOT a reason the population reached and maintained a plateau?
a. limits in food supply
b. competition with other species
c. competition for space
d. a major storm would probably not cause a population to maintain its size

7. Pair, Share, Explain
A population increase in which the population "overshoots" the carrying capacity, K, and then crashes precipitously. Note that after the crash the population rebounds somewhat and approaches a new stable size (dN/dt = 0). Note that the carrying capacity has also changed. In the case of the Kaibab deer, this would represent irreversible (or at least very long term) changes in the amount of food available.

8. “r”, “K” Strategist general characteristics
Survivorship Curves
CH52

9. “r” vs “K” Strategists
Survivorship curves

10. Additional Math practice
Population Dynamics…
Additional Math practice
Population Web Site

11. ...the Math… N = Population SIze dN = Change in Population Size
dt = Change in Time; generation
r = 1.0 = BR – DR
(2-1 in this case)

12. N = Population SIze
dN = Change in Population Size
dt = Change in Time; generation
r = 1.0 = BR – DR
(2-1 in this case)
1,500 = ?
*N small compared to K- Max rate of Increase
*N large/K limiting,
Rate of increase is small (K-N/K is close to zero)
SEE PP- Logistical-Exponential Lesson

13. Population Dynamics Birth rate/Death rate United States 14.1/8.7
Australia 12.7/7.3
Iraq 34.2/6.0
Japan 10.0/8.5
Italy 8.9/10.1
Russia 9.7/13.9
Other Factors?
Migration: Emigration,Immigration
Why?….for people…
Life Expectancy,Health Care,Sanitation
Economics,Quality of Life,Education

14. Density dependent vs independent factors
Density Dependent Factors: related to the density of the population. (disease, predation, competition)
Density Independent Factors: Not related to population size (killing frost, severe blizzard, hurricane, etc)
CH52#6

15. Three Patterns of Population Growth
Causes?

16. Census Bureau http://www.census.gov/population/international/data/
International Data
China
Single Birth Policy When Instituted?

17. 1978: single birth policy: China