Population ecology examines populations of species and how they change over time. Key features of populations include size, density, and dispersion. Population size is affected by birth and death rates. Density is measured as the number of individuals per unit area and is affected by factors like immigration, emigration, and environmental limits. Dispersion describes how organisms are spaced relative to each other, which can be clumped, even, or random. Populations can grow exponentially at first but eventually reach carrying capacity, where growth levels off due to environmental limits.

1. POPULATION ECOLOGY

2. POPULATION ECOLOGY Population: all the individuals of a species that live together in an area Demography: the statistical study of populations, make predictions about how a population will change

3. Population Dynamics Three Key Features of Populations Size Density Dispersion (clumped, even/uniform, random)

4. Three Key Features of Populations 1. Size: number of individuals in an area

5. Growth Rate = Birth Rate - Death Rate (# individuals born - # individuals die) Age Distribution Number of individuals in different age groups of a population Indicates the potential of a population to increase, decrease or remain stable in size over time RATE OF GROWTH & AGE DISTRIBUTION

6. PRE-REPRODUCTIVE REPRODUCTIVE POST-REPRODUCTIVE

7. Population of a Stable Country

8. THREE TYPES OF POPULATIONS

9. Which is growing faster? You decide!

10. Three Key Features of Populations 2. Density: measurement of population per unit area or unit volume Pop. Density = # of individuals ÷ unit of space

12. 1. Immigration- movement of individuals into a population 2. Emigration- movement of individuals out of a population 4 Factors that affect density

13. 4 Factors that affect density 3. Density-dependent factors- Biotic factors in the environment that have a greater limiting effect as population size increases Examples: disease competition parasites

14. 4. Density-independent factors- Abiotic factors in the environment that affect populations regardless of their density Examples: temperature storms habitat destruction drought 4 Factors that affect density

15. Immigration Emigration Births Deaths Population Change + + - - Factors That Affect Future Population Growth

16. Three Key Features of Populations 3. Dispersion: describes the spacing or organisms relative to each other clumped even or uniform random

17. clumped even (uniform) random THREE TYPES OF DISPERSION

18. Population Dispersion

19. OTHER FACTORS THAT AFFECT POPULATION GROWTH Limiting factor - any biotic or abiotic factor that restricts the existence of organisms in a specific environment Examples: Amount of water Amount of food Competition Predation Amount of living space Disease Parasitism Can be density dependent or independent

20. OTHER FACTORS THAT AFFECT POPULATION GROWTH Carrying Capacity- the maximum population size that can be supported by the available space and environmental resources Carrying capacity can change as limiting factors become more or less severe for a given population

21. TWO BASIC PATTERNS OF POPULATION GROWTH Carrying Capacity (k) Nu m b e r Time J-shaped curve (exponential growth) S-shaped curve (logistic growth)

23. CARRYING CAPACITY -------------------------------------------------- CARRYING CAPACITY

24. 2 Life History Patterns 1. R Strategists short life span small body size reproduce quickly have many young little parental care Examples: cockroaches, weeds, bacteria

25. 2 Life History Patterns 2. K Strategists long life span large body size reproduce slowly have few young provides parental care Examples: humans, elephants

26. HUMAN POPULATION THROUGH THE AGES

27. HUMAN POPULATION THROUGH THE AGES

28. Human Population Growth