1. POPULATION REVIEW

2. Population All the individuals of a species
that live together in one place.
Population

3. The area inhabited by a population
geographic range

4. Population density Number of individuals per unit area. Two ducks
Hundreds of fish

5. Distribution

6. The number of individuals in a population.
Population size

7. The increase in the size of a population over time.
Population growth

8. When does a population grow?
A population grows when births exceed deaths.

9. What does a population need to grow?
water
food
space
few predators
less disease

10. What type of growth is this?
Exponential growth

11. What is exponential growth?
Exponential growth is how a population grows
in the beginning when resources are plentiful.
As the population
gets larger,
it grows faster.

12. Populations do not grow exponentially forever.
Population growth is limited by
food
water
predators
disease
space
These are limiting factors

13. Limiting factors Any biotic or abiotic factor that regulates
the growth of a population.
Limiting factors

14. Some limiting factors may be
water
food
predators
disease
competition
temperature
natural disasters

15. Some density-dependent limiting factors are:
water
food
predators
disease
competition

16. Some density-independent limiting factors are:
flood
earthquake
wild fires
drought
hurricanes
natural disasters
temperature

17. Limiting factors prevent a population
from growing exponentially forever.
Therefore, most organisms’ populations
follow a logistic growth curve, an S-shaped curve.
Number of Organisms
Time

18. Logistic growth
occurs when a population’s growth slows and
then stops, following a period of exponential growth.

19. Phases of Growth: The population grows rapidly.
The population remains constant.
The population growth slows.
The population
grows slowly.

20. Logistic Growth (S-shape)
Growth slows.
Carrying
capacity
Growth
stops.
Population
grows rapidly.

21. The maximum number of individuals of a species
that an environment can support.
Carrying capacity
1000

22. What is the carrying capacity?
1000 bison.
1000

23. Populations fluctuate around the carrying capacity.

25. Desertification –
turning farm land into desert as a result of
over farming, overgrazing, and seasonal drought.

26. Deforestation –
Loss of forest as a result of clear-cutting.

27. Biological magnification –
when a pollutant accumulates in organisms.
Top predators have the highest concentration of pollutant.

28. Primary succession is the colonization of new sites by communities of organisms. It often occurs after a devastating event has wiped out the organisms that lived in the area, or with the creation of a new habitat. 

29. Secondary succession is the ecological succession that occurs on a preexisting soil after the primary succession has been disrupted or destroyed due to a disturbance that reduced the population of the initial inhabitants.
soil

30. Invasive species –
a plant or animal that is not
native to a specific location;
and has a tendency to spread,
and cause damage to the environment.

31. Invasive species in Florida: python, iguana, lionfish