Chapter 5 Populations

1
Chapter 5Populations

• Section 5-1
• How Populations Grow

2
How Populations Grow
3
Characteristics of Populations

• Key Concept
• Three important characteristics of a population
  are its
• geographic distribution
• density
• growth rate.

4
Population Density

• The number of individuals per unit area.

5
Population Growth

• In stable ecosystems, populations tend to stay
  the same size year to year.

6
Population Growth

• Key Concept
• Three factors can affect population size
• Birthrate
• Deathrate
• Immigration and Emigration of members of the
  Population

7
Exponential Growth

• Occurs in populations with
• abundant space
• abundant food
• no disease
• no predators

8
Exponential Growth

• Key Concept
• Under ideal conditions, with unlimited resources,
  a population will grow exponentially.

9
Exponential Growth
10
Logistic Growth

• Key Concept
• As resources become less available, the growth of
  a population slows or stops.

11
Logistic Growth

• Characterized by a S shaped growth curve. Pg.
  122, fig. 5-4

12
Carrying Capacity

• The largest number of individuals a given
  environment can support.
• Analyzing Data, Pg. 123