1. BIOZONE: None BIOZONE: None
Sponge: Set up Cornell Notes on pg. 21
Topic: C.5 Population Ecology
Essential Question: Two centuries ago, there were only one billion people on Earth. Today, over 6 billion. Which phase of the s- curve are we in?
BIOZONE: None
C.5 Population Ecology
Two centuries ago, there were only one billion people on Earth. Today, over 6 billion. Which phase of the s-curve are we in?
Key Vocabulary:
Natality
Mortality
Immigration
Emigration
Carrying Capacity
S-shaped curve
Exponential phase
Transitional Phase
Plateau Phase
BIOZONE: None

2. PICTURES P. 20 Natality Mortality Immigration Emigration
S-shaped Curve Picture

3. Understandings- The phases show in the sigmoid curve can be explained by relative rates of natality, mortality, immigration and emigration

4. Population Dynamics
1. Natality- the # of new members of the species due to reproduction
2. Mortality- the # of deaths
Draw pictures that represent each P. 20

5. 3. Immigration- the number of individuals arriving from other places
4. Emigration- the number of individuals leaving the population
Draw pictures that represent each P. 20

6. Population Dynamics
After Mt. St. Helen’s Eruption, the massive mortality rate reduced the population #s to about zero
Emigration before and immediately following the eruption greatly decreased populations in the wider vicinity
Today, immigration and natality are improving the population #s dramatically

7. Population Growth Curve
After an event that wipes out most life (Mt. St. Helens), there can be a dramatic increase in population #s
Over the years, the # of trees and birds with rise at ever-increasing rates as the organisms reproduce and occupy available space

8. Population Growth Curve
Eventually a complete forest will grow again, and all habitats will be occupied
The numbers of organisms will stabilize and not get any bigger

9. The Sigmoid (s-Shaped) Curve
The sigmoid (s-shaped) curve shows the three stages of population growth

10. White Boards!!! Get Your Whiteboards!!!!
Remainder of p. 21
S-shaped Curve
Exponential Growth Phase
Transitional
Phase
Plateau
Phase
White Boards!!! Get Your Whiteboards!!!!

11. The Sigmoid (s-Shaped) Curve
1. Exponential Growth Phase (logarithmic phase): the numbers of individuals increases at a faster and faster rate

12. Exponential Phase
In ideal conditions, a population can double on a regular basis (not counting mortality)
What are these “ideal” conditions? (Whiteboards)
Plentiful resources (space/food/light)
Little or no competition (food/mates/…)
Abiotic resources (temp/climate)
Little or no predation
Little or no disease

13. The Sigmoid (s-Shaped) Curve
2. Transitional phase: the growth rate slows down considerably- the population is still increasing but at a slower and slower rate

14. Transitional Phase
What will begin to happen as growth rate continues to increase?
Eventually, some of the previously listed factors above will no longer be true. This leads to the transitional phase:
As population number increases, competition increases
Predators will be attracted to a growing food supply and move in
As numbers increase, and crowding occur, diseases begin to spread

15. The Sigmoid (s-Shaped) Curve
3. The Plateau Phase (Stationary phase): the number of individuals has stabilized- there is no more growth

16. Plateau Phase
Once all the fertile ground is covered with plants the space available will be occupied to its maximum (less available room for seeds)
With increasing #s of herbivores, there will be a limited supply of food (in response, animals have less offspring)
Predators and disease increase mortality rate
Growth curve tends to level off

17. Understandings- Population growth slows as a population reaches the carrying capacity of the environment

18. Carrying Capacity
Carrying capacity is the maximum # of individuals that a particular habitat can support
No habitat can accommodate an unlimited number of organisms (populations cannot grow forever)
Carrying capacity---- “K”

19. The Sigmoid (s-Shaped) Curve
Is an idealized version of population growth
Exponential phase- natality is high and mortality is low
Transitional phase- natality is lower and mortality is higher
Plateau phase- natality and mortality are equal and emigration and immigration are equal
The ideal population is in dynamic equilibrium at the carrying capacity of the environment

20. s-Shaped Curve Draw on the bottom of P. 20 USE 3 COLORS TO CODE
Carrying Capacity K

21. NEW SEATING CHART-stand in back/side of room Get out homework
Sponge: Set up Cornell Notes on pg. 23
Topic: C.5 Population Ecology
Essential Question: NONE.
BIOZONE: None
C.5 Population Ecology
None.
Key Vocabulary:
Density-independent
Density-dependent
Bottom-up control
Top-down control
BIOZONE: None
NEW SEATING CHART-stand in back/side of room
Get out homework

22. White Boards!!! Get Your Whiteboards!!!!
What are some factors that would LIMIT the carrying capacity of a habitat?

23. Factors that change the sigmoid growth curve
Availability of resources:
water
food
sunlight
shelter
space
oxygen
Build up of waste such as excrement or excess CO²
Predation
Disease

24. Examples of factors that change the sigmoid growth curve
Abiotic- temperature- cold temps could increase mortality rates
Biotic- a living organism can be introduced to “control” population #s (i.e. an invasive species)
Density independent- Any factor limiting the size of a population whose effect is NOT dependent on the number of individuals in the population. An example of such a factor is an earthquake.
Affects all of the population equally
Density dependent- Any factors where the effects on the size or growth of a population vary with the density of the population itself. An example of such a factor is loss of space.
Affects large populations and small populations differently- (i.e. disease spreading)

25. Population Dynamics Worksheet

26. Understandings- Limiting factors can be top down or bottom up.

27. Limiting Factors
The limiting factors that define the carrying capacity of a population can exert:
Top-down control
Predators
Bottom-up control
nutrients

28. Limiting Factors
Bottom-up control: refers to ecosystems in which the nutrient supply/productivity and type of primary producers control the ecosystem structure
Ex: Plankton populations are controlled by the availability of nutrients
More nutrients= more plankton
nutrients

29. Limiting Factors
Top-down control: refers to ecosystems in which a top predator controls the structure or population dynamics of the ecosystem
Ex: Sea otters in the kelp forest.
Keystone predator: prey on sea urchins which eat kelp. When otters are removed, kelp forest ceases to exist.

30. Limiting Factors
It is most common for populations to be influenced by both types of control

31. Application- Bottom-up control of algal blooms by shortage of nutrients and top-down control by herbivory

32. Skill- Modeling the growth curve using a simple organism such as yeast or species of Lemna

33. Challenge Yourself- due tomorrow
Bottom-up: Nutrients (increase algal blooms that negatively affect the coral)
Top-down: Herbivorous fish that eat the algae (keep the reef healthy)

34. Challenge Yourself- due tomorrow
1. What are your overall observations of the impact that reduced or elevated nutrients have on the algae mean percent cover?

35. Challenge Yourself
2. For study site A, compare the mean percentage cover of all three alga types with reduced and elevated nutrients. What were the resulting effects on the coral?
Crustose corallines:
Cc appears to have a much higher mean percent cover with reduced nutrients over elevated nutrients
There is much less Cc cover when nutrient levels are high
Frondose macroalgae:
Fm appears to have a much higher mean percent cover with elevated nutrient levels
Algal turfs:
At appear to have a higher mean percent cover when nutrients are reduced

36. Challenge Yourself
3. For site A, the prediction was that macroalgae would be dominant in the competition for percentage cover with elevated nutrients. Was the prediction correct? GIVE EVIDENCE to support your answer.
Yes. F. macroalgae has a mean percentage cover of 63.7 vs. 1.8 for C. corallines and 14.5 for A. turfs.

37. Challenge Yourself
4. Describe a benefit to the coral reef that occurred over the 24 months at site D.
The mean percent cover of C. corallines is dominant (71.7) over the two other (sometimes harmful) algae. F. macroalgae is at 16.9 and A. turfs is at 22.1

38. Challenge Yourself
4. Explain the conditions under which eutrophication-induced (nutrient enriched) microalgae (A. turfs) blooms decreased the growth of the reef-building corals (C. corallines).

39. BIOZONE: None. BIOZONE: None.
Sponge: Set up Cornell Notes on pg. 25
Topic: C-5 Population Ecology
Essential Question: Describe the major differences between r-strategists and K- strategists. Include examples.
BIOZONE: None.
C-5 Population Ecology
Describe the major differences between r-strategists and K-strategists. Include examples.
Key Vocabulary:
r-strategy
K-strategy
BIOZONE: None.

40. 24
Zebra mussel v Zebra

41. Understandings- The exponential growth pattern occurs in an ideal, unlimited environment

42. Which of these two organisms is most likely to survive an ecological disaster which caused extreme changes in both terrestrial (land) and aquatic ecosystems?
Zebra Mussel
Zebra

43. P. 24 Habitat (environment)
In order to answer this question properly, we need to understand some background information about the animals in question:
With your table, make a list (whiteboards- 2 per table) of everything you know about the
Habitat (environment)
Reproduction (offspring #/parenting styles/reproduction rate)
Growth rate
Food habits
Life span
Size
…. of the zebra mussel or zebra (feel free to use internet on phone)
P. 24
Zebra Mussel
Zebra

44. Known as K-strategist Known as r-strategist Live up to 40 years
Zebra
Zebra Mussel
Live up to 40 years
Requires a stable environment
Long gestation period (pregnancy) during which the mother needs good nutrition
Baby zebra need maternal care
Savannah must have enough food
In the event of an ecological disaster: The few offspring produced would NOT survive
Known as K-strategist
Live 4-5 years
Unstable environment
Lays thousands of eggs which hatch into free swimming larvae
Most of the eggs will die (eaten)
Hundreds will survive
No parental care
In the event of an ecological disaster: A few would be likely to survive
Known as r-strategist

45. K-strategist (K=carrying capacity)
r-strategist (rate)
K-strategist (K=carrying capacity)

46. r-strategists
Organisms that live in unstable environments tend to make many, "cheap" offspring
r-selected species, also called r-strategist,  are species whose populations are governed by their biotic potential or the maximum rate at which a population can increase. (r=rate)

47. K-strategists
Organisms that live in stable environments tend to make few, "expensive" offspring.
K-selected species— species whose population sizes fluctuate at or near their carrying capacity (K)

48. Assessment Statement
Discuss environmental conditions that favor either r-strategies or K-strategies
Use whiteboards to brainstorm:
Life span:
Size:
Reproduction rate:
Offspring #s:
Parental care:
Growth rate:
Type of environment they live in:
Includes examples of animals

49. r- Strategy K- Strategy Mostly insects Life span short
Many offspring- most are lost
“disposable” offspring
Early maturity-grow quickly
Small body size
Usually only reproduce once during lifetime
No parental care
Unstable environments
K- Strategy
Almost all mammals
Long life span
Few offspring
“non disposable” offspring
Later maturity-grow slowly
Larger animals
Produce offspring more than once during life span
Parental care likely-Nurturing
Stable environment

50. Ecological Disruption:
Favors r-Strategists!!!!!
If you call something a “pest”, its likely an r-strategist
It is adapted to become established quickly before its competitors get a foothold
In a balanced ecosystem, the r-strategists have interactions with other species that control their numbers (they get eaten)

51. BIOZONE: None. BIOZONE: None. Essential Question: None.
Sponge: Set up Cornell Notes on pg. 27
Topic: Population Decline Case Study: Why Have all the Sea Lions Gone?
Essential Question: None.
BIOZONE: None.
Population Decline Case Study:
Why Have all the Sea Lions Gone?
BIOZONE: None.

52. “Mystery in Alaska: Why Have All The Sea Lions Gone?”

53. Background Information: Steller Sea Lions
Please read/highlight the Steller Sea Lion information sheet
Note key details on their diet (food habits), population size, and predators/hunting

54. “A Mystery in Alaska”- Clip 3m47s
Please take 5 bullets on the video on pg. 26

55. Discussion on Monday-Finish as HW
P Mystery in Alaska
With a Partner please read and answer the questions in the case study
Part I---- Cross off #2
Part II----Cross off #4
Part III
FOR BOTH FISH:
1. Question is asking to calculate the NUMBER OF CALORIES per 100g of fish
Multiply the % of fat-proteins-carbs by the calories per gram of each
(Ex: if a certain fish has 2% fat= 2x 9 cal/g= 18 fat calories) Do this for all three.
Add all calories together for final answer (18 fat cals+____pro cals+ ____carb cals= Total # of cals)
2. Question is asking to calculate the PERCENT OF CALORIES for each
Divide the # of calories fat-protein-carbs by the TOTAL # of calories (answer from #1) (ex: 18 fat cal/ Answer from #1) Do this for all three.
Discussion on Monday-Finish as HW

57. Steller Sea Lion Population Decline and Increase

58. The Good News…