1. 4.1- Population Dynamics [part 1] SPI 2 Interpret the relationship between environmental factors and fluctuations in population size. Goals: Understand how density, distribution, and range define populations, and become familiar with population limiting factors

2. Joke of the day Why don't aliens eat clowns? Because they taste funny.

3. Population Attributes Population Density: –The number of organisms per unit of area.

4. Population Ranges –The range that populations of certain species can live depends on their adaptability to the abiotic and biotic factors of other habitats. Kiwi Bird in New Zealand Cows everywhere

5. Population Attributes Spatial Distribution: –How a population is spread out over an area; where they can be found Random Uniform Clumped

6. Unpredictable b/c of resources: White-tailed Deer Herds: Bison, Cows Territorial animal: bear

7. Population Limiting Factors Density-independent –Any factor in the environment that DOES NOT depend on the population density Usually abiotic  Natural Disasters Human Activity  Dams, Clear-cutting, air pollution

8. Density-dependent –Any factor that DOES depend on the population density Often biotic  predation, competition, disease, parasites

9. Predation…wolf and moose populations

10. Competition… –When density increases, competition increases as there is less resources to go around –Food, space…etc.

11. Disease…population density matters! How often have you gotten sick in the first few weeks back to school?

12. Parasites- like disease, parasites spread easily in larger populations