1. 6/8/2016SB4d1 ECOLOGY Population Growth

2. SB4D Students will assess the dependence of all organisms on one another and the flow of energy and matter within their ecosystems. D. Assess and explain human activities that influence and modify the environment such as global warming, population growth, pesticide use, and water and power consumption. 6/8/2016 SB4d 2

3. 6/8/2016 SB4d 3 Population Growth Increase in population = population growth Population Growth Rate = the change in the number of individuals in a population over time

4. Population Dispersion The way in which individuals of a population are spread in an area 6/8/2016 SB4d 4

5. Clumped vs. Uniform Dispersion 6/8/2016 SB4d 5 Live in close proximity for mating, protection, and/or food access Due to territoriality and intraspecific competition

6. Random Dispersion 6/8/2016 SB4d 6 Spread randomly within an area

7. Survivorship Curve Shows the number of surviving members over time from a measured set of births. – Type I—low level of infant mortality and will survive until old age (mammals and humans) – Type II—survivorship rate is equal at all stages of life (birds, mammals, reptiles) – Type III—very high birth rate, very high infant mortality (inverts, amphibians, plants) 6/8/2016 SB4d 7

9. 6/8/2016 SB4d 9 Population Growth Biotic Potential The rate at which a population will grow if all individuals in a population survive and reproduce at maximum capacity This is the ideal environment Unlimited resources No hazards Does not exist in real world

10. Population Growth Four factors can affect the size of a population: Immigration Births Emigration Deaths 6/8/2016 SB4d 10

11. 6/8/2016 SB4d 11 Growth Curves Graphs showing the number of individual in a population over time 2 types Exponential (J shaped curve) Logistic curve (S shaped curve)

12. 6/8/2016 SB4d 12 Exponential Growth Due to an increase in resources J shaped curve 2 phases Lag phase – little or no increase in population growth Exponential phase – rapid population growth

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14. 6/8/2016 SB4d 14 Logistic Growth S shaped curve Represents the Carrying Capacity Carrying Capacity = the max number of individuals the ecosystem is capable of supporting Just enough resources Sudden drop in population causes a population crash.

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16. 6/8/2016 SB4d 16 Limits to Growth Density Dependent Factors Density Independent Factors Limiting factors are factors that cause population growth to decrease.

17. 6/8/2016 SB4d 17 Limits to Growth Density Dependent Factors Factors that affect populations depending on population density Competition Food Water Space Shelter Predation Availability of mates Availability of parasites and disease

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19. 6/8/2016 SB4d 19 Limits to Growth Density Independent Factors Factors that affect populations regardless of population size Generally abiotic factors Ex: weather changes Ex: natural disasters Ex: human activities

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21. 6/8/2016 SB4d 21 Human Population From 6000 BC to 1800 AD the number of people increased slowly Mid 1800’s human population began to grow exponentially Why? Agricultural revolution Industrial revolution Advances in medicine

22. 6/8/2016 SB4d 22 Human Population In 1650 – 500 million people In 1930 (about 300 years later) – 2 billion people Today (about 70 years later) – over 6 billion people By 2050 – between 7.8 and 12.5 billion This is based on population growth in China and India

23. 6/8/2016 SB4d 23 Human Population Humans have been able to push the carrying capacity of the Earth past what it really should be Ability to cultivate crops Ability to domesticate animals Ability to cure diseases Eventually we will run out of space and possibly resources

24. 6/8/2016 SB4c24 Ecology Succession

25. SB4C Students will assess the dependence of all organisms on one another and the flow of energy and matter within their ecosystems. C.Relate environmental conditions to successional changes in ecosystems. 6/8/2016 SB4d 25

26. 6/8/2016 SB4c 26 Ecological Succession Process of ecosystems changing over time 3 types Primary Succession Secondary Succession Eutrophication

27. 6/8/2016 SB4c 27 Primary Succession Establishment and development of a once inhabited area Natural Succession Begins with bare area (ex: volcanic island) Pioneer Species = 1 st organisms to appear Generally lichens and weeds (fast growing) Eventually fast growing trees Mimosa, pines Last – slow growing trees Oaks trees This is called a Climax Community

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30. 6/8/2016 SB4c 30 Secondary Succession Same process as primary succession But occurs in areas that have been disturbed (soil intact) Natural disasters Human activities There is no end to secondary succession Tree falls, process starts again

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32. 6/8/2016 SB4c 32 Eutrophication Succession in ponds and lakes Ponds and lakes slowly fill up with land