1. Ch. 4 Population Ecology

2. I.Population Dynamics - Biological processes constantly influence a population’s density, dispersion, and growth rate. Tent Caterpillars

3. A.Population Characteristics 1.Population Density - number of organisms per unit area

4. 2.Spatial Distribution - uniform, clumped, random Uniform Clumped Random

5. 3.Population Range - depends on the species’ adaptations to biotic and abiotic factors Range of the Cougar Range of the Olympic Marmot

6. B.Population-Limiting Factors 1.Density-Independent Factors - affect organisms regardless of population size Forest Fire Tsunami

7. 2.Density-Dependent Factors - competition, predation, disease and parasites Year 1850187519001925 0 40 80 120 160 0 3 6 9 Lynx population size (thousands) Hare population size (thousands) Lynx Snowshoe hare Snowshoe Hare and Lynx

8. 2.Density-Dependent Factors Host-Parasite Relationship: Bean Weevil vs. Braconid Wasp

9. C.Population Growth Rate - balance between biotic potential and environmental resistance Births Immigration Population Size Emigration Deaths Deaths and emigration remove individuals from a population. Births and immigration add individuals to a population.

10. C.Population Growth Rate - balance between biotic potential and environmental resistance - Natality: birth rate - Recruitment: joining the breeding population - Mortality: death rate - Immigration - Emigration

11. 1.Exponential Growth - shows an increasing growth rate (J-shaped curve) - results in population explosion

12. 1.Exponential Growth 1900 1920194019601980 Year 0 2,000 4,000 6,000 8,000 Elephant Population Exponential Growth in the African Elephant Population of Kruger National Park, South Africa

13. 1.Exponential Growth

14. 2.Logistic Growth - population growth levels off at carrying capacity (S-shaped curve) 1,000 800 600 400 200 0 180 150 0 120 90 60 30 Time (days) 05 10 15 0 160 140120 80 1006040 20 Number of Paramecium/ml Number of Daphnia/50 ml Paramecium population Daphnia population

15. 3.Boom - and - Bust Population Cycle -population greatly exceeds carrying capacity resulting in a population crash Annual lake algal bloom Conditions good: Boom Conditions bad: Bust

16. 1911 - 25 reindeer introduced 1938 - 2000 reindeer 1950 - 8 reindeer survived food (lichens) overgrazed St. Paul Island, Alaska Effects of Exceeding Carrying Capacity

17. D.Reproductive Patterns R-strategists K-Strategists

18. 1.R-Strategists - adapted to unstable environments - short life spans - produce many offspring Chum Salmon Locust Swarm

19. 1.R-Strategists - adapted to unstable environments - short life spans - produce many offspring Chum Salmon Dandelion

20. 2.K-Strategists - adapted to more stable environments - long life spans - produce fewer offspring

21. 8000 B.C. 4000 B.C. 3000 B.C. 2000 B.C. 1000 B.C. 1000 A.D. 0 The Plague Human population (billions) 2000 A.D. 0 1 2 3 4 5 6 II.Human Population Growth -Humans are undergoing a population explosion.

22. Human Population Growth

23. A.Technological advances have increased carrying capacity for humans -agricultural improvements -advances in sanitation and medicine - decrease in childhood mortality

24. B.Demographic Transition -shift from high birth and death rates to low birth and death rate

25. C.Rate of increase has slowed

26. Demographic Transition in Sweden and Mexico, 1750–2050 (Data as of 2003) 50 40 20 0 30 10 1750 1800 1850 1900 1950 2000 2050 Birth rate Death rate Birth rate Death rate Year SwedenMexico Birth or death rate per 1,000 people

27. Human Population Growth Rate by Country

28. Age Structure Pyramids for the Human Population of Three Countries (2003) Rapid growth Afghanistan Slow growth United States Decreas e Italy Male Female Male FemaleMale Female Age 864202468864202468864202468 Percent of population 80–84 85  75–79 70–74 65–69 60–64 55–59 50–54 45–49 40–44 35–39 30–34 20–24 25–29 10–14 5–9 0–4 15–19 80–84 85  75–79 70–74 65–69 60–64 55–59 50–54 45–49 40–44 35–39 30–34 20–24 25–29 10–14 5–9 0–4 15–19

29. Age Structure Diagram for Japan in 1950, 2005, and 2050 1950 2005 2050

30. Infant Mortality and Life Expectancy at Birth in Developed and Developing Countries Developed countries Developing countries Developed countries Developing countries Infant mortality (deaths per 1,000 births) Life expectancy (years) 60 50 40 30 20 10 0 80 60 40 20 0

31. Ecological Footprint in Relation to Available Ecological Capacity 16 14 12 10 8 6 4 2 0 0 2 4 68 1214 16 New Zealand Australia Canada Sweden World China India Available ecological capacity (ha per person) Spain UK Japan Germany Netherlands Norway USA Ecological footprint (ha per person)

32. The End