1. Limiting Factors Ecosystems

2. Let’s suppose…. We have two mice…: and they produce the standard 56 “pups” (baby mice) each year. and each of these mice goes on to have 56 babies each year….

3. Soon….. We’d be over-run with mice on the planet!! Why doesn’t this occur?

4. Limiting Factors A limiting factor is an abiotic or biotic factor that restricts the number of individuals in a population.

5. Limiting Factors Limiting factors can include but not limited to: 1. Competitors

6. Limiting Factors Limiting factors can include but not limited to: 1. Competitors 2. Disease and parasites

7. Limiting Factors Limiting factors can include but not limited to: 1. Competitors 2. Disease and parasites 3. Weather

8. Limiting Factors Limiting factors can include but not limited to: 1. Competitors 2. Disease and parasites 3. Weather 4. Fires

9. Limiting Factors Limiting factors can include but not limited to: 1. Competitors 2. Disease and parasites 3. Weather 4. Fires 5. Available habitat

10. Limiting Factors Limiting factors can include but not limited to: 1. Competitors 2. Disease and parasites 3. Weather 4. Fires 5. Available habitat 6. Predators

11. Competitors-organisms both cooperate and compete Red-Tailed HawkBarred Owl Birds of prey Live in forests on the edge of fields Eat mice and other rodents Nest in trees

12. Disease and Parasites Diseases and parasites can be dependent on population size and habitat

13. Weather Storms Drought Flooding Heat/cold

14. Fires Fires lead to succession which is a predictable change in the community over time.

15. Available Habitat Human activities play a large role Development, damming rivers, clear cutting forests.

16. Predators Predator-prey relationship can be a delicate balance between the two populations.

17. Predators As the prey population increases, the predator population increases. As the prey population decreases, then so does the predator population.

18. Example: Lynx and Hare http://video.nhptv.org/video/1491196512http://video.nhptv.org/video/1491196512/

19. Carrying Capacity What would happen if 100 more people unexpectedly arrived for lunch? Would there be space for them around the table? Would there be enough food for them? Would everybody have to adapt or change a little to incorporate the newcomers? How would you feel if it were too crowded around the lunch table? What happens in a field or forest when there are too many animals? Some will move away or starve. Just as a pizza can only feed so many people, a field can only feed so many deer.

20. Carrying Capacity a limited number of organisms of a species that any one place can support Carrying Capacity Barrel