1. Aim: How are populations limited by the carrying capacity of the environment?

2. Relationships in an Ecosystem:
Predator vs. Prey
The stability of an Ecosystem is dependent on the balance of these
relationships/cycles.
Water Cycle
Photosynthesis

3. 3 Factors that can affect overall Population Size:
Number of births
Number of Deaths (causes of death?)
Number of members entering or leaving the population.

4. What limits the size of the student population?
EX: The number of desks, number of teachers, space

5. What factors can affect the size of a population?
Limiting Factors- anything that limits or decrease the size of a population
Abiotic Biotic

6. What abiotic factors that may limit the size of a population?
Sunlight
Temperature
Water
carbon dioxide
Oxygen
Drought (Climate Extremes)
Soil
minerals pH
Nutrients
Wind
Human Disturbances
Resources may be finite (limited) or infinite (unlimited)

7. What biotic ‘limiting factors’ can affect the size of a population?
Competition - the population that is the best adapted to the environment will increase and the other population will die out or will migrate

8. What are some examples of competition in an ecosystem?
Indirect Competition – struggle for resources among organisms in ecosystem.
Organisms best adapted to get the resources will survive and the other organisms will die or migrate

9. What are some examples of competition in an ecosystem?
Direct Competition – organisms hunt and kill each other

10. How Does Predation limit populations?
Predation (Predator-prey relationship)
Cyclical changes…how?

11. Movie – Importance of having predators

12. Carrying Capacity:
The maximum number of organisms that the ecosystem can support.
It is determined by the limiting factors & competition.

13. What happens to new, small populations?
The population usually will increase until the carrying capacity is reached and then the population will remain stable.

14. Can the carrying capacity of an environment change?
Yes, anytime there is a natural catastrophe or when humans take space away from the ecosystem
Natural disaster
Seasonal cycles
Human activities
Damming rivers, clear cut forests