1. Population Ecology

2. Ecology
ecology
environment
components
biotic
abiotic

3. Ecology Hierarchy of Ecology biosphere ecosystem community population
individual

4. Population Ecology 2 characteristics of a population: density
dispersion

5. Density we measure density by sampling mark and recapture method
line intercept method
point count method

6. Population Distribution
distribution patterns
clumped
uniform
random

7. Age Distribution
distribution of males and females in each age group of a population
used to predict future population growth

9. Survivorship mirrors mortality expressed in survivorship curves
plots surviving individuals at different age groups

10. Survivorship three types of survivorship curves late loss (Type I)
constant loss (Type II)
early loss (Type III)

13. Changes in a Population
3 factors determine population changes
births
deaths
migration
immigration
emigration

14. Population Dynamics measures optimal population growth J curve
exponential growth
measures optimal population growth
rmax = intrinsic rate of increase

15. Population Growth example: 10,000 birds in a population
1500 births and 500 deaths per year
1500/10, /10,000 = .10 or 10%
expressed by saying there is a 10% increase per bird per year

17. Population Dynamics size of a population is limited to:
intrinsic rate of increase
environmental resistance
includes limitations the environment imposes on birth rate and death rate in a population
food
space
predation
parasitism

18. Population Growth and Regulation
carrying capacity (K)
determined by
renewable resources like water, nutrients, and light
nonrenewable resources such as space

19. Carrying Capacity logistic population growth
r decreases as N increases
K-N tells us # of individuals population can accommodate
S curve

21. Population Growth Models
K selected
equilibrial populations
live at density near limit imposed by resources
r selected
opportunistic populations
live in environments where little competition is present

22. Density Influence on Birth and Death Rates
2 mechanisms
density independent
density dependent

23. Density Independent Factors
unrelated to population size
most important:
weather
climate

24. Density Dependent Factors
increase effectiveness as population density increases
especially affects long lived organisms
include
predation
parasitism
competition

25. Human Population Growth
J curve growth
grows at a rate of about 80 million yearly (r=1.3%)
Why doesn’t environmental resistance take effect?

26. Human Population Growth
altering their environment
technological advances
the cultural revolution
the agricultural revolution
the industrial-medical revolution