Ecosystems

1. Ecosystems Limiting Factors

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: • Competitors

6. Limiting Factors • Limiting factors can include: • Competitors • Disease and parasites

7. Limiting Factors • Limiting factors can include: • Competitors • Disease and parasites • Weather

8. Limiting Factors • Limiting factors can include: • Competitors • Disease and parasites • Weather • Fires

9. Limiting Factors • Limiting factors can include: • Competitors • Disease and parasites • Weather • Fires • Available habitat

10. Limiting Factors • Limiting factors can include: • Competitors • Disease and parasites • Weather • Fires • Available habitat • Predators

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

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: