Population Growth Curves

1. Population Growth Curves How and why populations change

2. How wolves change rivers • How many wolves were added to the ecosystem? • What was the first change that happen in the ecosystem because of the wolves? • How did the change in the producer population effect the ecosystem? • What is the most shocking effect of the wolves being added to the ecosystem?

4. Population size • 3 important characteristics of a population are its. • Geographic distribution • Density (how thick or thin they are) • Growth Rate

5. Determining Population size Growth Shrink Increased death rates Emigration: moving out • Increased birth rates • Immigration: moving into

6. Growth Curves • Exponential Growth (J- shaped) Curves • The population grows continuously. • There are NO limits of the population size. • Unlimited resources.

9. Growth Curves • Logistic Growth (S-Shaped) Curve • The population can only grow so much • There are limits on the population • There is a limited amount of resources that the population can use. • Carrying Capacity (K) is the maximum organism that can survive in a specific ecosystem. The limit is reached.

13. Limiting Factors • Density-Independent factors: • Anything Weather related • Volcanos • Earthquakes • Hurricanes • Tornados • Forrest fires • Drought • Floods • Humans

14. Limiting Factors • Density-Dependent Factors • With in the population, population size • Space • Shelter • Competition • Disease • Parasitism

15. Limiting Factors • These factors keep populations within a specific range. • They define the Carrying Capacity (K) on population size.

16. Human Impact • Humans can have a positive and negative effect on populations • Hunting • Developments • Pollution • Zoos • Protected Lands • 5 Human Impacts on the Environment: Crash Course