1. Population Growth Population Density
# of organisms per unit area
Factors that affect population size:
# of births
# of deaths
# of people immigrating and emigrating

2. Exponential Growth
Individuals in a population reproduce at a constant rate
Population gets larger and larger very quickly
Occurs under ideal conditions
Unlimited space, food, no predators, etc.

3. Logistic Growth Many real life situations have limitations on growth
Eventually the growth of the population will slow down or stop

4. What limits population growth? (Limiting Factors)
Density-Dependent
Produces a logistic growth pattern
Only become limiting when the population gets large:
Competition (for food, water, space, shelter)
Predation
Parasitism
Disease
Density-Independent
Produces a “Boom and Bust Curve”
Limit growth of the population regardless of the size of the population:
Weather
Natural disasters
Seasonal cycles
Certain human activities

5. Boom and Bust Curve: Results from Density-Independent Factors

6. Application: complete Analyzing Data on p.123 in your text