1. Populations

2. A Population
group of organisms of the same species living in the same place at the same time

3. Different populations are all connected!
When one population decreases or increases in an ecosystem, another population can be affected!
Example: The story of the sea otters!

5. Figure 1.15 page 18

6. When the sea otters are absent…

7. Carrying Capacity
The maximum population that an environment can sustain or support.
Seychelles Paradise Flycatcher needs one acre of mixed forest per breeding pair. They live on the little island of Madagascar

8. Carrying Capacity
a population remains at its carrying capacity when in balance (number of individuals added and the number of individuals that leave or die are the same)

9. Factors Determining Carrying Capacity
materials & energy: energy, water, carbon, and other essential nutrients (Abiotic Factors)

10. Factors Determining Carrying Capacity
2. Food chains: the population size is limited by the size of the populations at lower trophic levels

11. Factors Determining Carrying Capacity
3. Competition: each organism has the same need as any other; they compete for resources such as food, water, mates and space

12. 3. A closer look at Competition: Two types of competition:
Intraspecific competition: among members of the same species
ex: two wolves compete for a rabbit
Interspecific competition: between different species
ex: cheetah and lion compete for zebra

13. 4. Population Density: depending on their size, environment and way of life, different species have different needs for space

14. Density Dependent Factors
Occur when the density has gone beyond an appropriate level
Over-population can:
Increase stress & lead to easier spread of diseases and parasites
Increases aggression & causes parents to neglect offspring
This causes the population to decrease

15. Density Independent Factors
Limits the population- no matter what the density is.
Forest fires
Earthquakes
Volcanic Eruptions
Tornadoes
Floods

16. To Do:
Vocabulary Words and questions at the end of your sheet of notes
Sheet - Population Terms

17. Video - Populations Ecology - Crash Course

18. Population Growth Curves

19. Population Growth
if unlimited resources are present, growth will be exponential
the curve will always be a “J” curve or an exponential growth curve

21. resources are never unlimited
as population rises, resources decline
if the growth is too rapid, resources are rapidly depleted and a population crash can occur
this pattern occurs often with many populations (including humans)

22. Elk

23. Video - The Importance of Predators

24. more often what happens is that the resources slowly decrease, the growth rate slowly increases, and they meet
this point that they oscillate around is the carrying capacity of the environment for that particular organism
this is called an s-shaped or logistic
curve

25. To do: Notes: Population Growth Curves/
Practice Sheet: Carrying Capacity
Practice Sheet: Fruit Flies and population growth

26. Human Population Growth
What are the causes of this huge increase in the human population?
What are some possible consequences for us?
Our future? (Think: the elk)

27. To Do: Video: 7 Billion Current World Population
Activity: Human Population Growth

28. Video – How many people can live on planet Earth? (45 min)
Video – How Many People Can Earth Support (10 min)
Movie – Future Earth (45 min)

29. Movie - World Population to hit 11 Billion in 2100 (45 minutes)
Movie – Overpopulated (1 hour)
Video – The Science of Overpopulation (crash course) – 10 minutes