1. Populations

2. Describing Populations
Geographic Range: Area inhabited by population
Density: Number of individuals per unit area
Distribution: How individuals are spaced within a population
Random Uniform Clumped
Growth Rate: population numbers changing
Age Structure: Number of males and females of each age
Why is this important?

3. Random, Uniform, or Clumped??

4. Population Growth Rate
What factors affect growth rate??
Birthrate
Death rate
Immigration
Emigration

5. Exponential Growth
Definition: The larger a population gets, the faster it grows
When does this occur?
Under ideal conditions, unlimited resources

6. Logistic Growth
Definition: When a population’s growth slows and then stops, following a period of exponential growth.
Carrying Capacity: The maximum number of individuals of a species that a particular environment can support

7. Limiting Factors
Definition: Factors that control the growth of a population and
determine the carrying capacity
Density-Dependent Factors: Affect populations
significantly only when population reaches a certain size
Density-Independent Factors: Affect all populations in
similar ways, regardless of size and density