1. Chapter 5 Population Ecology Charateristics: geographical distribution, density and growth

2. Population Density  Measures how crowded a population is Unit examples? City vs Suburbs vs Rural

3. Population Distribution  Three main ways –Clumped –Random –Uniform/Even  Most common? Rare?

4. Distribution patterns

5. Population Dynamics  Birth rate = number of births over time  Death rate = deaths over a period of time  Life expectancy = how long individuals in pop. are expected to live –Take a guess: life expectancy for men and women in United States  Men = 72 years  Women = 76 years

6. Population Growth Rate  Growth rate= change in population size over time  Depends upon the following: –Birth –Death –Immigration –Emigration

7. Age Structures

9. Effects of AIDS on a Population

10. Questions- be ready to answer  What is a rate?  What is birth rate?  What is death rate?  What are two additional factors that cause a population to increase? Decrease?  What does per capita or % annual growth rate mean?

11. Growth Rate  What is a rate? –Change over time –In math terms = slope  What is birth rate? death rate? –Number of births over a period of time –Number of deaths over a period of time

12. Growth Rate Growth Rate  Two factors that increase population growth –Births –Immigration  Two factors that decrease population growth –Deaths –Emmigration

13. Growth rate %%%% GROWTH RATE? - takes into account total growth (births and immigration) minus decline (death and emmigration) –C–C–C–Change in growth over time  L L L Look at fig 5-14 on page 132 WWWWhat does ZPG mean? –Z–Z–Z–Zero population growth WWWWhat years had the highest % growth rate?

14. Population Growth can be represented bycharacterized by represented by which cause a Exponential growth Logistic growth Falling growth rate S-shaped curve Limits on growth No limits on growth J-shaped curve Constant growth rate Unlimited resources Section 5-1 Concept Map

15. Exponential Model for Population Growth  Says that populations grow rapidly after only a few generations  Bacteria follow this model

16. Logistic Model  Populations are limited by their environment  Any factor that limits population growth is called a limiting factor  Limiting factors include things like food, habitat availability, water, predators

17. Carrying Capacity (K)  The number of individuals the environment can support over a long period of time.  This number is due to birth rates, death rates, and limiting factors

19. Humans – how long?

20. HW – CH 5 Study Guides due Tues!

21.  5–2Limits to Growth A.Limiting Factors B.Density-Dependent Factors 1.Extinction 2. Competition 3.Predation 4.Parasitism and Disease C.Density-Independent Factors Section 5-2 Section Outline

22. Population Fluctuations 1. Density-independent factors- reduce population by the same proportion regardless of population size; ex. Cold winter effects the squirrel population –It doesn’t matter the size of the population 2. Density-dependent factors- resource limits due to increase in population density; ex. Shortage of food due to too many deer in the area causes some deer to starve.

23. Fluctuations Change the Graph

24. Extinction  What if an organism went extinct?  What would the graph look like?

25. What about small populations?  Very vulnerable to extinction  Why is that?  Inbreeding  Something bad happens in the environment and too many die to sustain the population  Ex. Cheetahs, sea otters, CA Condors, Siberian tigers

26. 60 50 40 30 20 10 0 195519601965197019751980198519901995 2000 1600 1200 800 400 0 2400 MooseWolves Section 5-2 Figure 5-7 Wolf and Moose Populations on Isle Royale

27. Human Populations

28.  They have exploded over the last 1000 years  The death rates have decreased and the birth rates have increased. This makes the overall growth rate increase.  Do you think that this current human population is sustainable?  Do you think that we are way past our carrying capacity and it will go down?

29. Agriculture begins Plowing and irrigation Bubonic plague Industrial Revolution begins Section 5-3 Human Population Growth