1. Chapter 4: Population Ecology

2. Section 1: Population Dynamics
Populations are a group of the same species living in the same geographic area.
Important features of populations:
Population Density
Dispersion
Geographic Distribution
Growth Rate

3. Population Density
Density is the number of species within a unit area-(concentration)
Different for each species and ecosystem
Based on biotic and abiotic factors

4. Dispersion Pattern of spacing of a population within an area
Three types:
Uniform
Clumped
Random
Figure 2, page 93 (Zebra book)

5. Geographic Distribution
The area where something is located or where a species lives and reproduces
Population range
Distribution based on organisms’ ability to adapt to biotic and abiotic conditions
in an area
Figure 2, page 93 (Zebra)

6. Population Limiting Factors
A limiting factor is a biotic or abiotic factor that can limit growth
Can be density-dependent or density-independent
Density-dependent factors
Affect of factor increases with increasing population density
Competition
Predation (Fig. 5, pg 96)
Parasitism and Disease

7. Limiting Factors, continued
Density-Independent Factors
Affect of factor does not depend on population density
Climate changes, natural disasters, and human disturbances
Fig. 4, page 95

8. Population Growth
Population growth is the change in the size of a population
Factors that affect growth:
Birth rate- # of births in a population over a period of time
Death rate- # of deaths in a population over a period of time
Immigration (moving in) and Emigration (moving out)

9. Job Offer Job #1 Job #2 Penny Lab Starting salary= $2000
Raise= increased $2000/day
Job #2
Starting salary= $0.01
Raise= Salary doubled every day
Penny Lab

10. Exponential Growth Seen in populations with unlimited resources
Exponential growth is
unlimited
2 mice3 mil. mice
in 2 years
* J-Curve

11. Logistic Growth
Population shows exponential growth until a resource becomes limited
Growth is slowed or stopped when population size reaches carrying capacity
Carrying capacity (k) is the amount of individuals in a population that an area can support
Tim & Moby on Populations

12. Section 2: Human Population
Demography is the study of the size of human populations
Growth rates are controlled by the same factors as animal populations
Birth Rate
Death Rate
Immigration (IN) and Emigration (OUT)
Age Structure

13. Historical Demography
Human population used to be low and relatively stable
Limited by resources and disease
Past 500 years
Exponential growth as limits have been removed

14. Age Structures
Histogram depicting the number of people in each age category within a population (Figure 14, page 104)
Can be used to predict future growth

15. Chapter 5: Biodiversity and Conservation

16. Section 1: Biodiversity
Biodiversity is the
variety of life in an area.
Important because:
Provides varied resources
Food
Products
Medicines
Creates ecosystem stability
Biodiversity is measured
by species diversity; the
number of different
species in an area

17. Genetic Diversity The variety of genes present in a population
Increases a species chances of survival during:
environmental changes
an outbreak of disease
the disappearance of a food source

18. Geographic Distribution of Biodiversity; also see fig. 3, pg 117

19. Threats to Biodiversity
Habitat Loss
Deforestation
Overexploitation (overuse)
Habitat Fragmentation
Pollution
Biomagnification, acid precipitation
Introduction of Invasive species
Threats to Biodiversity

20. Habitat Loss

21. Overexploitation (overuse)
The excessive use of species that have economic value
Bison hunted for meat, hides, and just for sport
Population went from 50 million to 1000
Passenger pigeons
Now extinct
Ocelot and white rhinoceros
Overexploitation used to be the number one reason for extinction; now it’s habitat destruction

22. Habitat Fragmentation – fig. 12, page 126

23. Pollution Water Land Air Chemicals, Trash, Temperatures,
Eutrophication (causes algae overgrowth)
Land
Chemicals, Trash
Air
Chemicals and Noise

24. Effect of Pollution: Biological Magnification
Chemical pollutant becomes more concentrated as it moves up the trophic levels within a food chain or web
Very dangerous for top level predators
Fig. 13, page 126

25. Acid Precipitation Effects

26. Invasive (Introduced) Species
Also called non-native species
Introduced to new habitat
Often grows without check because of lack of natural predators or disease in the area
Decreases biodiversity in an area
Fig. 15, page 128

27. Losing Biodiversity Species experiences a decline in growth Threatened
Canadian lynx
Prairie dog
Endangered
Bald Eagle
Many Marine Mammals
Extinct
Dodo
Passenger Pigeon

28. Section 3: Conserving Biodiversity
Pages
Class Activity: reading “Natural Resources”
1’s Read “Protecting Biodiversity”
2’s read “Restoring Ecosystems”
Think Aloud with your table partner and take your own notes

29. Effects of Pollution: Ozone Depletion; Ozone; Greenhouse Effect
While watching the BrainPop clips, answer the following:
1. What is ozone? Include chemical formula!
2. Why is it important to the atmosphere?