1. Population and Community Ecology
Interdependence

2. Objectives
Investigate and understand dynamic equilibria within populations, communities, and ecosystems.
Key concepts include:
interactions within and among populations including carrying capacities, limiting factors, and growth curves;
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

3. Population Dynamics
Population: all the individuals of a species that live together in an area
Demography: the statistical study of populations, make predictions about how a population will change
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

4. Population Dynamics Three Key Features of Populations Size Density
Dispersion
(clumped, even/uniform, random)
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

5. Three Key Features of Populations
1. Size: number of individuals in an area
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

6. Three Key Features of Populations
Growth Rate: Birth Rate (natality) - Death Rate (mortality)
i.e. How many individuals are born vs. how many die
Birth rate (b) − death rate (d) = rate of natural increase (r).
What was the growth rate of the deer population?
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

7. Boom and Bust Curve

8. Boom and Bust Curve Increase rapidly for a time
Decrease rapidly due to
Disease
Starvation etc.
The predators of these organisms follow the cycle

9. Human Population Growth
What are some factors that affect human population growth?
___
____
Graph the data

10. Human Population Growth

11. Human Population Growth

12. Exponential Growth – J curve
Multiplies by a constant factor each time interval
Slow beginning
Rapid increase

13. Carrying capacity – S curve
Limiting factors
Flattens out the J curve
What are the factors?
Carrying capacity of the population
Number of organisms that the environment can support.

14. J-shaped curve (exponential growth)
Carrying Capacity Nu m b e r
J-shaped curve (exponential growth)
Carrying Capacity (k)
S-shaped curve (logistic growth)
Ok so
Time

15. Three Key Features of Populations
2. Density: measurement of population per unit area or unit volume
Formula: Dp= N
Pop. Density = # of individuals ÷ unit of space
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat. S

16. Factors that affect density
1. Immigration- movement of individuals into a population
2. Emigration- movement of individuals out of a population
3. Birth
4. Death

18. Other factors that affect population growth
Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.
EX.- Amount of water
Amount of food
Temperature

19. Factors that affect density
Density-dependent factors- Biotic factors in the environment that have an increasing effect as population size increases
  Ex. Disease, starvation
competition
parasites

20. Factors that affect density
Density-independent factors- Abiotic factors in the environment that affect populations regardless of their density
  Ex. temperature
storms
habitat destruction
drought

21. POST-REPRODUCTIVE
REPRODUCTIVE
PRE-REPRODUCTIVE

22. Population of a Stable Country  

24. You decide!