1. Population Ecology Notes

2. Before we start, think about…
How is the human population growing? What do you think affects population growth?
Potential Openers

3. Population Growth
Growth rate of a population is the amount by which a population’s size changes in a given time.

4. Population Growth
Exponential Growth = population grows as if there are no limitations as to how large it can get.
E.g., bacteria initially growing on an agar plate in the incubator

5. Population Growth and Size
Carrying capacity (K) = maximum number of individuals that a population can sustain in a given environment without destroying the habitat

6. Limiting Factors Control Population Sizes
Density-dependent factors come into play when population approaches and/or passes the carrying capacity
Food supplies, waste products, space/habitat size, population-crowding diseases

7. Limiting Factors Control Population Sizes
Density-independent factors have nothing to do with the population size
- Examples: Floods, droughts, earthquakes, other natural disasters and weather conditions

8. Population Growth
Logistic Growth = population growth slows to zero and population size stabilizes because of limiting factors
More realistic model of population growth in nature

9. When does a logistic growth stop increasing?
When carrying capacity (K) is reached!