1. Do Now 11/10/15
Bell-Ringer
What is population Density and name two types of dispersion
Grab New Ecology Part 2 Packet

2. Population
Dynamics

3. Population Ecology
Population Ecology is the science of understanding the change in populations over time.
2 levels of study
Whole Population
Cohort- who you live
with
Each species has a unique pattern of development, reproductive rate, migration, and survivorship

4. X. Population Dynamics All species occur in groups called populations
Limiting factors = factors that are biotic or abiotic that keep a population from continuing to increase indefinitely

5. What Affects Population Size?
Some Limiting Factors
BIRTHS
DEATHS
Immigration
Emigration
“Reproduction rate”
Density
Parental ability and status
“Mortality rate”
- predation
- disease
- birth issues
Definition: Moving INTO a new area
Reasons:
Resources
Mates
Food
etc
Definition: EXITing a area
Competition
Population density
Others?

6. X. Population Dynamics 2 types of Population-Limiting Factors:
density-independent factors
density-dependent factors
BRAINSTORM IN GROUPS

7. X. Population Dynamics
Density-independent factors = Any factor in the environment that does not depend on the number of members in a population per unit area
Usually abiotic (natural phenomena)
Ex:
Weather events (tornadoes, floods, hurricanes)
Fire
Human alterations of the landscape
Air, land, and water pollution

8. X. Population Dynamics
Density-dependent factor = Any factor in the environment that depends on the number of members in a population per unit area
Usually biotic
Ex:
Predation
Disease- (high population density--> disease quickly spreads)
Parasites
Competition – food, space limitations

9. Do Now: 11/12/15
Target: I know the difference between exponential growth and logistic growth
Bell-Ringer: 20 acre farm has 20 deer, 10 acre farm has 2 deer- which has bigger density?
Get out Bio notes packet

10. X. Population Dynamics
The population growth rate (PGR) explains how fast a given population grows.

11. Four phases Lag Phase – Period of no growth
Exponential Growth Phase- Tons of growth
Deceleration Phase- slows down
Stable Equilibrium Phase - stabilizes

13. X. Population Dynamics
Exponential growth (J curve) Growth Curve is smooth and becomes infinitely steep
All populations grow exponentially until some limiting factor slows the population’s growth.

14. X. Logistic Growth ( S Curve)
The population’s growth slows or stops following exponential growth, at the population’s carrying capacity. – DUE TO LIMITING FACTORS

15. X. Population Dynamics
A population stops increasing when the number of births is less than the number of deaths or when emigration exceeds immigration.

16. X. Population Dynamics
Carrying capacity = The maximum number of individuals in a species that an environment can support for the long term.
Where Births start to relatively equal deaths in the population – write down in margin of notes

17. Carrying Capacity
limited by the energy, water, oxygen, resources, and nutrients available.
Population can also exceed carrying capacity (Overshoot)- deaths outnumber births because resources are not available to support all individuals

18. Homework
Pages in Ecology part 2 packet
Due Monday!

19. Do now 11/13/15
Bell-ringer
Which period in time correlates with the start of human exponential growth?
A) the plague
B) “the baby boom”
C) the industrial revolution

20. POPULATION PYRAMIDS

21. Human Population
Human Population Growth Rate – influenced heavily by the industrial revolution
The study of human population size, density, distribution, movement, and birth and death rates is demography.

22. Zero Population Growth
Zero population growth (ZPG) occurs when the birthrate equals the death rate.

23. What is a population pyramid?
It is a diagram that gives information about the proportion of males and females in each age group.
Also shows:
- proportion of young people (0 -14 )
- proportion of working people (15 – 59)
- proportion of elderly people (60+)

24. What is a population pyramid?
Vertical Axis - Age Groups
Elderly dependents
Working population
Young dependents
Horizontal Axis – Percentage / number

25. How to read a population pyramid?
Read the title e.g. country or city or racial group
Comment on general shape of the pyramid
Note the proportion of people in various age groups
Note the sex ratio
Interpret the data

26. Types of Population Pyramid
1. Triangular shaped
2. Beehive-shaped Pyramid
3. Rectangular-shaped Pyramid
Shape of pyramids is controlled by
births,
deaths, &
migrations.

27. You can also determine Growth Patterns by looking at these graphs

28. Population Pyramids in Transition

29. Each pyramid tells a story about the past, present & future of a country & its people.

30. Importance of Population Pyramids
Policy Planning
~ future housing estates
~ future schools
~ future jobs
Comparison with other countries
~ developed (US) vs developing (India)

31. What is biodiversity?
Biodiversity is the variety of life in an area that is determined by the number of different species in that area.
Biodiversity increases the stability of an ecosystem and contributes to the health of the biosphere.

32. Types of Biodiversity
The variety of genes or inheritable characteristics that are present in a population comprises its genetic diversity.
Genetic diversity increases the chances that some species will survive during changing environmental conditions or during the outbreak of disease.

33. Types of Biodiversity
The number of different species and the relative abundance of each species in a biological community is called species diversity.

34. With your neighbor….
What environmental factors might be involved in the increasing diversity of species as one moves from northern latitudes to the tropics?

35. How do the two compare in regards to species diversity?

36. The Importance of Biodiversity
Most of the world’s food crops come from just a few species.
Wild species serve as reservoirs
of desirable genetic traits that
might be needed to improve
domestic crop species.

37. A disease comes through that only effects people with blue eyes – Brainstorm in your groups why genetic diversity is important for this issue? Would species diversity be helpful here?

38. What things do you think have greatly impacted changes on Earth?
Extinction Rates
The gradual process of species becoming extinct is known as background extinction.
Mass extinction is an event in which a large percentage of all living species become extinct in a relatively short period of time.
What things do you think have greatly impacted changes on Earth?

40. Overexploitation
Overexploitation, or excessive use, of species that have economic value is a factor increasing the current rate of extinction.
Examples
Bison
Passenger pigeons
Rhinoceros
Ocelot

41. Habitat Fragmentation
The separation of an ecosystem into small pieces of land is called habitat fragmentation.
Carving the large ecosystem into small parcels increases the number of edges—creating edge effects.

42. Biological magnification
Biological magnification is the increasing concentration of toxic substances in organisms as trophic levels increase in a food chain or food web.

43. Eutrophication
Eutrophication occurs when substances rich in nitrogen and phosphorus flow into waterways, causing extensive algae growth.

44. Introduced Species
Nonnative species that are either intentionally or unintentionally transported to a new habitat are known as introduced species.

45. Other threats Habitat Loss Destruction of Habitat
Disruption of Habitat
Pollution
Acid Precipitation