1. Ch. 8 Env. Science Ch. 5 Biology
Population Dynamics
Ch. 8 Env. Science
Ch. 5 Biology 1

2. Population Dynamics
Population: all the individuals of a species that live together in an area

3. Population Dynamics
Demography: the statistical study of populations, make predictions about how a population will change

4. Population Dynamics Three Key Features of Populations Size Density
Dispersion
(clumped, even/uniform, random)

5. Three Key Features of Populations
Size: number of individuals in an area
Estimate by sampling
Mark-Recapture Method
Ok so 5

6. 2. Density: measurement of average population per unit area or unit volume
Formula: Dp= N
Pop. Density = # of individuals (population size) ÷ unit of space S

8. Whitetail Deer Population Density

9. Three Key Features of Populations
3. Dispersion:describes their spacing relative to each other
clumped
even or uniform
random

10. clumped
even (uniform)
random

11. Population Dispersion

12. Population Size
Growth Rate: Birth Rate (natality) - Death Rate (mortality)
How many individuals are born vs. how many die
Birth rate (b) − death rate (d) = rate of natural increase (r).

13. POST-REPRODUCTIVE
REPRODUCTIVE
PRE-REPRODUCTIVE

14. Population of a Stable Country
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat. 14

15. Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat. 15

16. You decide!

17. Factors That Affect Future Population Growth
Immigration + + -
Population
Mortality
Natality
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat. -
Emigration 17

18. Factors that affect growth
3. Immigration- movement of individuals into a population
4. Emigration- movement of individuals out of a population
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat. 18

19. Growth Rate : Reproductive Potential
Reproductive Potential = maximum number of offspring that each member can produce
Darwin proposed that it would take elephants 750 years for elephants to produce 19 million descendants. Bacteria can do this in a few days

20. Growth Rate : Reproductive Potential
Increases:
more offspring at a time
reproduce more often
earlier in life (generation time)

21. 2 Types of Growth Curves Exponential Growth - grow faster and faster
Logistic Growth - levels off due to limited resources

22. Exponential Growth population increases rapidly
only occurs in nature when there is plenty of food and space, and have little or no competition or predators.

23. Logistic Growth population decreases as resources become scarce
leveling off when the carrying capacity of the environment is reached
resulting in an S-shaped curve.

24. Growth Curves

25. Carrying Capacity
Carrying Capacity- the maximum population size that can be supported by the available resources
There can only be as many organisms as the environmental resources can support

26. J-shaped curve (exponential growth)
Carrying Capacity
N u m b e r
J-shaped curve (exponential growth)
Carrying Capacity (k)
S-shaped curve (logistic growth)
Time 26

27. Limiting Factors
Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.
EX.- Amount of water
Amount of food
Temperature

28. 2 Types of Limiting Factors
1. Density-dependent factors-
Biotic factors in the environment that have an increasing effect as population size increases
  Ex. disease
competition
parasites
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat. 28

29. 2 Types of Limiting Factors
2. Density-independent factors- Abiotic factors in the environment that affect populations regardless of their density
  Ex. temperature
storms
habitat destruction
drought