1. In this unit you will learn about how to: Analyze how ecosystems differ from each other due to abiotic and biotic factors.

2. LIVING THINGS AND THE ENVIRONMENT

3. A prairie dog is one type of organism. Each organism must live in a specific type of environment. An organism obtains food, water, shelter, and things it needs to live, grow, and reproduce from its environment. An environment that provides the things the organism needs to live, grow and reproduce is called its habitat.

4. An organism interacts with both the living and nonliving parts of its habitat. The living parts of a habitat are called ____________. biotic factors

5. The nonliving parts of an organism’s habitat are called ____________. abiotic factors Abiotic factors include: -water -sunlight -oxygen -temperature -soil

6. ECOLOGICAL ORGANIZATION Organism (prairie dog) Population (prairie dog town) Community (all the living things that interact on the prairie) Ecosystem (all the living and nonliving things that interact on the prairie)

7. CHANGES IN POPULATION SIZE Population can change in size when new members join the population or when members leave the population. BIRTH RATE: The number of births in a population in a certain amount of time. DEATH RATE: The number of deaths in a population in a certain amount of time.

8. CHANGES IN POPULATION SIZE If birth rate > death rate = If death rate > birth rate = Population increases Population decreases If death rate = birth rate = Population Stays the same

9. POPULATION DENSITY - The number of individuals in a specific area. What is the formula to calculate population density? Population Density = Number of individuals _____________ Unit Area

10. Calculate the population density of flamingos. Population Density 10 flamingos ___________ 8 square meters =1.25Flamingos/ square meter =

11. Calculate the population density of flamingos. Population Density = 20 flamingos ___________ 8 square meters =2.5Flamingos/ Square meter

12. The largest population an area can support is called its ____________. carrying capacity The carrying capacity of a population is determined by limiting factors. Limiting factor: An environmental factor that causes a population to decrease. foodwaterspaceweather conditions