1. How Populations Grow
Ecology

2. POINT > Explain density-dependent population factors
POINT > Explain density-independent population factors

3. POINT > Identify density-dependent and density-independent population factors
Many factors control the growth of a population and determine the carrying capacity of an environment
Some of these factors depend on population density, others do not

4. POINT > Explain density-dependent population factors
Density-dependent factors operate strongly only when population density reaches a certain level (low density populations are less affected)
As population
Effects of Factor

5. POINT > Identify density-dependent population factors
Four density-dependent factors: 1. Competition for resources… Food Light Mates Water Nutrients Space/Territory

6. POINT > Identify density-dependent population factors
Four density-dependent factors:
2. Predation & Herbivory
Cycle up and down over time (in response to one another)
Humans play a major role as predators

7. POINT > Identify density-dependent population factors

8. WB CHECK:
An increase in the wolf population in an area is likely to
have no effect on moose population
cause the moose population to increase
cause the moose population to decline
lead to more disease in the moose population

9. WB CHECK:
An increase in the moose population in an area is likely to
have no effect on wolf population
cause the wolf population to increase
cause the wolf population to decline
lead to more disease in the wolf population

10. What are 4 things organisms might compete for?
WB CHECK:
What are 4 things organisms might compete for?

11. POINT > Identify density-dependent population factors
Four density-dependent factors: 3. Parasitism & Disease The denser a population, the more easily parasites and pathogens can be spread (ex. flu epidemics)

12. POINT > Identify density-dependent population factors
Four density-dependent factors: 4. Stress (from overcrowding) tends to make animals more susceptible to disease (immune suppression)

13. WB CHECK:
A disease can spread more rapidly in a high density population area because
overcrowding stress can suppress the immune system
individuals are in contact with each other more often
individuals have fewer resources
all of the above
a and b
c and b

14. WB CHECK:
What are 4 density-dependent factors that can affect population growth?

15. POINT > Identify density-independent population factors
Density-independent factors affect all populations in similar ways, regardless of population size and density
Ex. Natural disasters / Extreme weather conditions
(drought, flooding, tornado, hurricane, wildfire, extreme temperature, etc)

16. Homework: Read 5.2 pages 137-141 Assess page 141#1-3 Workbook 330-331, 334