1. Wednesday, January 18, 2017 Ecology Unit 5 TARGETS:
I: Identify and define different levels of ecological organization
III: Analyze and explain survivorship curves: Types I, II, & III. Explain how r-selected & K-selected species relate to specific curve types
IV: Analyze and explain logistic and exponential growth curves
V: discuss how biotic & abiotic limiting factors (density dependent & density independent) affect population size
HOMEWORK:
*SEE ONLINE CALENDAR – complete virtual pop. growth pre-lab pages 1-3. Show formulae & work for each pre-lab problem

2. Levels of ecological organization
DEFINITION
LEVEL
EXAMPLE(S)
INDIVIDUAL
POPULATION
COMMUNITY
ECOSYSTEM
BIOME
One member of a species
A group of the same species that live in the same area
Many different populations that live together in the same area
All organisms AND their physical environment in a particular place
Major terrestrial & aquatic zones of life based on vegetation type

3. INDIVIDUAL
POPULATION
COMMUNITY
ECOSYSTEM
BIOME
BIOSPHERE

4. Limiting Factors Target V
BIOTIC
_____________Factors: Any living part of the environment with which an organism and or a population might interact
Predators, Prey
EXAMPLES:
Mates
Other, competing species
Trees (forest habitat)

5. Limiting Factors Target V
ABIOTIC
_____________Factors: Any non-living part of the environment with which an organism and or population might interact
Temperature (daily, seasonally)
EXAMPLES:
Amt O2, CO2, sunlight
pH of water, soil
Type, mineral content, & amt of soil
Amount, type, & frequency of precipitation
Amt of sunlight
Amt & quality of water
Wind speed & direction

6. Population dispersion and density relate to limiting factors
Dispersion – pattern of spacing among individuals within the boundary of a population area
EXAMPLES: clumped, uniform, or random
Density - # of individuals / area (or volume)
EXAMPLE:

7. Survivorship Curves
Target III
How long are members of a certain age (and of a certain gender) within a population expected to live?
Three types
TYPE I
TYPE II
TYPE III
Generate many examples of species that exhibit each type

8. Figure 53.6: Survivorship Curves Target III
What are other organisms have a Type I survivorship curve?
What are other organisms have a Type III survivorship curve?

9. Survivorship Curves Relate to Life History
How long do organisms live?
How long does it take for organisms to reach sexual maturity?
How often do organisms reproduce in their life time?
How many offspring are produced per reproductive event?
For how long is parental care provided to offspring?
How much time & energy do parent(s) spend feeding, raising, & teaching offspring?
K-selected life history
r-selected life history

10. Figure 53.6: Survivorship Curves Target III
Which curve best represents r-selected species? WHY?
Which curve best represents K-selected species? WHY?

11. Survivorship Curves Relate to Life History
LIFE HISTORY: relates to reproduction strategies, environmental selection pressures, AND evolution
SEMELPARITY: “big bang,” all or none reproduction
Occurs for TYPE III survivorship curve species
Occurs when there is a low chance offspring will live to adulthood
Environment is unpredictable, unstable
ITEROPARITY: repeated reproduction over lifetime
Occurs for TYPE I survivorship curve species
Occurs when there is a high chance offspring will live to adulthood
Environment is stable

12. How Populations Grow EXPONENTIAL GROWTH LOGISTIC GROWTH Target IV
Figure: 29-05
Title:
Three models of growth for natural populations.
Caption:

13. How Populations Grow Target IV EXPONENTIAL GROWTH J-shaped curve
New generation is double the size of the last
Growth occurs if organisms move to a new environment
•Seems like there are no limiting factors regulating the population size; unlimited resources are available
Figure: 29-05
Title:
Three models of growth for natural populations.
Caption:

14. Figure 53.10: Exponential Growth (J-curve) Target IV

15. How Populations Grow Target IV LOGISTIC GROWTH S- shaped curve
Slow growth at first
Short period of rapid
growth
Growth levels off at
carrying capacity
•Limiting factors
prevent population
from exponential
Figure: 29-05
Title:
Three models of growth for natural populations.
Caption:

16. Figure 53.12: Logistic Growth (S-curve) Target IV

17. How Populations Grow Target IV
Figure: 29-05
Title:
Three models of growth for natural populations.
Caption:
CARRYING CAPACITY
•The maximum number of organisms of a particular species that can be supported by an ecosystem
•NOT constant: can be altered by changes in biotic & abiotic factors within an ecosystem (annually)

18. How Populations Grow Target IV
Figure: 29-05
Title:
Three models of growth for natural populations.
Caption:
What kind of growth does the human population demonstrate? Explain your answer.

19. Draw on the board a J-curve and guide students through the exponential growth handout (last page of the packet they got on Wednesday with the levels of ecological organization on the first page)
Then, do the logistic growth

20. Limits to Growth Target V
CARRYING CAPACITY is determined by LIMITING FACTORS
DENSITY-DEPENDENT LIMITING FACTORS
Limit the size of a population when the number of organisms in a given area reaches a high level
Intra-species and interspecies competition
Predation
Figure: 29-05
Title:
Three models of growth for natural populations.
Caption:
Parasitism
Disease
Herbivory

21. Predator – prey interaction between moose and wolves
Limits to Growth Target V
CARRYING CAPACITY is determined by LIMITING FACTORS
Figure: 29-05
Title:
Three models of growth for natural populations.
Caption:
Predator – prey interaction between moose and wolves
As number of moose increase, the # of wolves increase.
As # of moose decrease, the number of wolves decreases.

22. Limits to Growth Target V
CARRYING CAPACITY is determined by LIMITING FACTORS
DENSITY-INDEPENDENT LIMITING FACTORS
Affect all populations equally regardless of population size and population density
Unusual weather/storms: hurricanes, tornadoes
Droughts
Figure: 29-05
Title:
Three models of growth for natural populations.
Caption:
Floods
Wildfires
Volcanic eruptions, earthquakes